lotus newsletter 2007 volume 37, number 2 - … · lotus newsletter.(2007). volume 37. number 2....

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LOTUS NEWSLETTER 2007Volume 37, Number 2

Editor: M. Rebuffo INSTITUTO NACIONAL DE INVESTIGACION AGROPECUARIA

Editorial OfficeINIA La EstanzuelaColonia, UruguayPhone: +598-574-8000Email: [email protected] No.: +598-574-8012Web: http://www.inia.org.uy/sitios/lnl/

The opinions in this publication are those of the authors and not necessarily those of the Lotus Newsletter. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Newsletter concerning the legal status of any country, territory, city, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. Where trade names are used this does not constitute endorsement of or discrimination against any product by the Newsletter.

Front cover: Juan Ramón Acebes Ginovés and Felicia Oliva Tejera spoke about the endemic Lotus species of the Canary Islands (pp. 14-15) at the Workshop: Lotus as a model legume and a sustainable alternative for marginal land reclamation (Botanic Garden of the University of Valencia, Spain, September 6-7 2007). The photograph on the front cover shows flowers of Lotus berthelotii, one of the species from the Canary Islands. The picture was recorded at the Jardin Mundani, Mallorca, Islas Baleares, Spain, and authorized by its publication at Lotus Newsletter 37(2) by Juan Bibiloni Pou.

This Newsletter consists of informal reports which are presented to further the exchange of ideas and information between research workers. Consequently the data presented here are not to be used in publications without the consent of the authors. Images are copyright of the authors, and their reproduction is strictly prohibited without their consent.

Editor: M. Rebuffo INSTITUTO NACIONAL DE INVESTIGACION AGROPECUARIA

mailto:[email protected]

http://www.inia.org.uy/sitios/lnl/

http://www.jardin-mundani.com/


Lotus Newsletter (2007) Volume 37 (2), i-iv.

SEPTEMBER 6-7, 2007. VALENCIA, SPAIN

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ORGANIZADORES DEL WORKSHOP: WORKSHOP ORGANIZERS:

DR. JUAN SANJUÁN (EEZ-CSIC)

DR. OSCAR A. RUIZ (UNIVERSITAT DE VALENCIA)

SECRETARÍA DEL WORKSHOP: WORKSHOP SECRETARIAT:

ROSA FRÁPOLLI (EEZ-CSIC)

ENTIDADES COLABORADORAS: UNDER THE SPONSORSHIP OF:

MINISTERIO DE EDUCACION Y CIENCIA

Cátedra UNESCO de Estudios sobre el Desarrollo

CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS

ESTACION

EXPERIMENTAL DEL ZAIDIN

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Programme Thursday, September 6 8:30-9:00 Welcome. Manuel Costa Talens, Vicerector de Relacions Internacionals i

Cooperació, Universitat de València 9:00-9:30 Opening: Arnoldo Santos (Tenerife, Spain) A global survey of genus Lotus (Loteae-Fabaceae) Session 1: Lotus spp. Genetic and Genomic Resources 9:45-10:15 Jens Stougaard (Aarhus, Denmark) Lotus genetics and genomics: Resources and approaches 10:30-11:00 Coffee Break 11:00-11:30 Mónica Rebuffo (Colonia, Uruguay)

Genetic resources of forage legumes for agriculture-pastoral system in Uruguay 11:45-12:15 Hernán Acuña (Chillán, Chile)

Genetic resources and agropastoral systems in Chile 12:30-13:00 Miguel Dall’Agnol (Porto Alegre, Brasil)

Legume Utilization in Grazing Systems in Southern Brazil 13:15-15:00 Lunch Session 2: Taxonomy and Ecophysiology

15:00-15:30 Francisco Escaray (Chascomús, Argentina) Biodiversity of Lotus spp. in Devesa of l`Albufera (Valencia, Spain) 15:45-16:30 Josep Roselló Picornell (Valencia, Spain)

Evolution in insular Mediterranean Lotus. What we know and what should be known 16:45-17:15 Coffee Break 17:15-17:45 Juan R. Acebes (Tenerife, Spain) Lotus endémicos de Canarias, situación y potencial aprovechamiento. 18:00-18:30 Rolando León (Argentina) Río de la Plata grasslands and Lotus tenuis 18:45-19:45 Round Table. Chair Oscar Ruiz

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Friday, September 7 Session 3: Biochemistry and Biotechnology

8:30-9:00 Carmen López-Valiente (Valencia, Spain)

Germinative response of Lotus creticus to different temperatures and salinity conditions 9:00-9:30 Antonio Márquez (Sevilla, Spain)

Primary and secondary nitrogen assimilation in Lotus japonicus and the relationship with drought stress

9:45-10:15 Oscar Ruiz (Chascomús, Argentina) Lotus tenuis as keystone species for the Salado River Basin (Argentine) 10:30.11:00 Coffee Break 11:00-11:30 Carmen Lluch (Granada, Spain) Saline stress tolerance in legumes 11:45-12:15 Esther González (Pamplona, Spain) Legume carbon metabolism under stress: Lotus japonicus features 12:30-13:00 Francisco Escaray (Chascomús, Argentina) Condensed tannins in the Genus Lotus 13:00-13:30 Francesco Paolocci (Perugia, Italy) Genetic manipulation of condensed tannin biosynthesis in Lotus spp 13:30-15:00 Lunch Session 4: Microbiology

15:00-15:30 Milagros León Barrios (Tenerife, Spain)

Genetic diversity in the rhizobia isolated from endemic Lotus to the Canary Islands 15:45-16:15 Isabel Videira e Castro (Oeiras, Portugal) Use of Lotus/Rhizobium Symbiosis in Regeneration of Polluted Soils 16:30-17:00 Coffee Break 17:00-17-30 Nuria Ferrol (Granada, Spain)

Legumes as model plants to study nutrient transport processes in arbuscular mycorrhiza 17:45-18:45 Round Table, Chair Juan Sanjuán 18:45-19:00 Conclusions

Lotus Newsletter. (2007). Volume 37. Number 2.

Contents

Workshop: Lotus as a model legume and a sustainable alternative for marginal land reclamation

Program i

A. SANTOS. A global survey of genus Lotus (Loteae-Fabaceae). [Una visión global del género Lotus (Loteae, Fabaceae)] 52 Session 1: Lotus spp. Genetic and Genomic Resources [Recursos Genéticos y Genómicos en Lotus spp.].

J. STOUGAARD, N. SANDAL, N. JØRGENSEN, S. DAM, G. NAUTROP, J. FREDSLUND, B.K. HOUGAARD, S. RADUTOIU, L. TIRICHINE, L.H. MADSEN, E.B. MADSEN, Y. KEISUKE, P. ROMERO, A. JURKIEWICH, A. ALBREKTSEN, E.M.H. QUISTGAARD and E. FUKAI. Lotus genetics and genomics: Resources and approaches. 54 M. REBUFFO, R. ZARZA, O. BORSANI, E. CASARETTO, A. MESSA, M.M. SAINZ, R. SALDIAS, R. ALZUGARAY, F. CONDÓN, P. DIAZ, J. MONZA, D. RISSO, M. BEMHAJA, R. BERMUDEZ, W. AYALA, N. ALTIER, M. ZARZA. Genetic resources of forage legumes for agriculture-pastoral system in Uruguay. [Recursos genéticos de leguminosas forrajeras para sistema agro-pastoriles en Uruguay] 56 H. ACUÑA. Genetic resources and agropastoral systems in Chile. [Recursos genéticos y sistemas agro-pastoriles en Chile.] 57 M. DALL’AGNOL and S.M.S. BASSO. Legume Utilization in Grazing Systems in Southern Brazil. [Utilização de Leguminosas em Sistemas Pastoris do Sul do Brasil.] 59 Session 2: Taxonomy and Ecophysiology [Taxonomía y Ecofisiología]. F. ESCARAY, A. SCAMBATO, P. COLLADO ROSIQUE, A. VIZCAINO MATARREDONA, J. ROSELLO PICORNELL, M. ROSATO, C. ANTOLÍN TOMÁS, P. CARRASCO SORLI and O.A. RUIZ. Biodiversity of Lotus spp. in Devesa of l`Albufera (Valencia, Spain). [Biodiversidad de Lotus spp. En la Devesa de l`Albufera (Valencia, España)] 62 J.A. ROSELLÓ. Evolution in insular Mediterranean Lotus. What we know and what should be known. [Evolución en Lotus insulares Mediterráneos. Qué conocemos y qué deberíamos conocer] 64

J.R. ACEBES GINOVÉS and FELICIA OLIVA TEJERA. Current status and uses of the endemic Lotus to the Canary Islands. [Lotus endémicos de Canarias, situación y potencial aprovechamiento.] 65 R.J.C. LEÓN, G. STRIKER, P. INSAUSTI and S.B. PERELMAN. Río de la Plata grasslands and Lotus tenuis. [Pastizales del Río de la Plata y Lotus tenuis] 67 Session 3: Biochemistry and Biotechnology [Bioquímica y Biotecnología]. C. LÓPEZ VALIENTE, E. ESTRELLÉS, P. SORIANO and J. PICÓ. Germinative response of Lotus creticus to different temperatures and salinity conditions. [Respuesta germinativa de Lotus creticus a distintas temperaturas y condiciones de salinidad] 69 A.J. MÁRQUEZ, M. BETTI, M. GARCÍA-CALDERÓN, A. CREDALI, P. DÍAZ and J. MONZA. Primary and secondary nitrogen assimilation in Lotus japonicus and the relationship with drought stress. [Asimilación primaria y secundaria de nitrógeno en Lotus japonicus e interrelación con el estrés hídrico] 71 F.L. PIECKENSTAIN, M.J. ESTRELLA, A. SANNAZZARO, A. MENÉNDEZ, V. FRACAROLI, N. CASTAGNO, M. ECHEVERRÍA, J. PESQUEIRA, P. VERTIZ, R. PAZ, M.E. MICIELI, F. ESCARAY, V. BERGOTTINI, S. SCHULMEISTER, P. UCHIYA, B. ROSSO, A. ANDRES and O.A. RUIZ. Lotus tenuis as keystone species for the Salado River Basin (Argentine). [Lotus tenuis como especie clave para la Pampa deprimida del Salado (Argentina).] 74 C. LLUCH, N. TEJERA, J.A. HERRERA-CERVERA, M. LOPEZ, J.R. BARRANCO-GRESA, F.J. PALMA, M. GOZÁLVEZ, C. IRIBARNE, E. MORENO and A. OCAÑA. Saline stress tolerance in legumes. [Tolerancia al estrés salino en leguminosas] 76 E.M. GONZÁLEZ, E. LARRAINZAR, R. LADRERA, C. DE MIGUEL and C. ARRESE-IGOR. Legume carbon metabolism under stress: Lotus japonicus features. [Metabolismo del carbono en leguminosas bajo estrés: características de Lotus japonicus] 78 F. ESCARAY, J. PESQUEIRA, F. DAMIANI, F. PAOLOCCI, P. CARRASCO SORLI and O.A. RUIZ. Condensed tannins in Lotus species under salt stress. [Taninos condensados en especies de Lotus en condiciones de estrés salino] 81 F. PAOLOCCI, S. ARCIONI and F. DAMIANI. Genetic manipulation of condensed tannin biosynthesis in Lotus spp. 84

Lotus Newsletter. 2007. Volume 37. Number 2.

Session 4: Microbiology [Microbiología]. M. LEÓN BARRIOS and J. DONATE CORREA. Genetic diversity in the rhizobia isolated from endemic Lotus to the Canary Islands [Diversidad genética de los rizobios aislados de Lotus endémicos de las Islas Canarias] 86 I. VIDEIRA E CASTRO, P. SÁ-PEREIRA, F. SIMÕES, J.A. MATOS and E. FERREIRA. Use of Lotus/Rhizobium Symbiosis in Regeneration of Polluted Soils. [Utilização da Simbiose Lotus/Rhizobium na Regeneração de Solos Poluídos.] 87 N. FERROL. Legumes as model plants to study nutrient transport processes in arbuscular mycorrhiza. [Las leguminosas como plantas modelo para estudiar los procesos de transporte de nutrientes en micorrizas arbusculares.] 89

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Lotus Newsletter (2007) Volume 37 (2), 52 - 53.

Abstract, Workshop held at Valencia, 6-7 September 2007

A global survey of genus Lotus (Loteae-Fabaceae)

ARNOLDO SANTOS *

Unidad de Botánica-Instituto Canario de Investigaciones Agrarias (ICIA). Jardín de Aclimatación de La Orotava, Calle Retama 2, 38400 Puerto de la Cruz (Tenerife). Canary Islands- Spain. * Corresponding author click here for Spanish version Lotus (Fabaceae: Loteae) is a moderate size genus comprising 125 – 180 spp. (Sokoloff and Lock, 2005). It includes herbs, suffrutices, and small shrubs; some of the species have ornamental values (i.e., specially the Rhyncholotus group from Canary Islands), others have broad use as forage (i.e., particularly the L. corniculatus –birdstrefoil-complex, L. pedunculatus –bigtrefoil- and L. tenuis), and others are used as cosmetics. The tribe Loteae is closely related to Sesbaniea and Robineae. The genus is composed of several subgenera, although their boundaries are not clearly understood and additional taxonomic research is needed at supra-generic level. For instance, the latest edition of Flora Europaea does not recognize any subgenus and divide the genus into six sections (i.e., Lotus, Erythrolotus, Krokeria, Lotea, Pedrosia and Quadrifolium). In addition, Flora Europaea considers Dorycnium as a distinct genus. This taxonomic treatment is also followed by Flora Iberica. Lotus is mostly confined to the northern hemisphere with a few species in southern one (South America, Africa and Australia). Flora Europea distinguishes over 30 species in Europe, and the genus also occurs in North Africa and the Atlantic archipelagos of Azores, Madeira, Salvajes, Canaries and Cape Verde Macaronesian Islands. Over 20 species are endemic to these islands. Few species of the genus occur in East Africa, although some of them are found on high altitudes areas of the Somalia-Masai massif. The Arabia peninsula, Sokotra, and South Africa have a very limited number of species. This pattern is also found in the New World, where there are few species on North America, Central America, and/or South America. Hosackia, a genus previously placed within Lotus, has over 11 species in SW Canada, W USA, Mexico and Guatemala, although most of them are in California areas. Among them, Lotus corniculatus and relatives have been the subject of intensive research because their value as cash-crops. A main limitation for the agriculture exploitation of these species concerns the presence of cianogenetic compounds, and several research programs are under development at different countries to explore and increase its use. Nucleotide sequences of the ITS region of the nuclear ribosomal DNA have been used to obtain phylogenetic reconstructions. These molecular phylogenies have included species from North America (Allan and Porter, 2000) and from the Atlantic Islands (Allan et al., 2004). A recent taxonomic study by Sandral et al. (2006) concerned Lotus section Pedrosia, this study included all of the Macaronesian species, a selection of the North-western African ones and two species with a Mediterranean distribution, Lotus arenarius and L. creticus. Recent taxonomic research has relied mostly on flower, leaves and stipules traits and has been recently published by Kramina (2006). This recent study has helped to clarify taxonomic boundaries within the L. angustissimus complex, a taxon mostly found in Eurasia. Types of


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Lotus taxonomy 53

indumentum have been tacked in account by Mader and Podlech (1989) to differentiate marrocan species. Molecular systematic and morphological taxonomy research is currently been undertaken by Graeme Sandral (Australia), Botanical Gardens Orotava and Viera y Clavijo at Canary Is., and Isidro Ojeda (Vancouver, Canada). Several projects are trying to get commercial cultivar(s) that will help to reduce soil water recharge and salinity problems (Graeme Sandral and collaborators, Australia). Other projects are under development at Uruguay, Chile and Argentine trying to get a better use of Lotus spp. as forage plants including nitrogen fixation capacity. References ALLAN G.J. and PORTER J.M. 2000. Tribal delimitation and phylogenetic relationships of

Loteae and Coronilleae (Faboideae: Fabaceae) with special reference to Lotus : evidence from nuclear ribosomal ITS sequences. American Journal of Botany, 87, 1871-1881.

ALLAN G.J., FRANCISCO-ORTEGA J., SANTOS-GUERRA A., BOERNER E. and ZIMMER E.A.

2004. Molecular phylogenetic evidence for the geographic origin and classification of Canary Island Lotus (Fabaceae: Loteae). Molecular Phylogenetics and Evolution, 32, 123-138.

KRAMINA T.E. 2006. A contribution to the taxonomic revision of the Lotus

angustissimus-complex (Leguminosae, Loteae). Wulfenia, 13, 57-92. MADER U. and PODLECH D. 1989. Revision der marokkanischen Arten von Lotus L.

subgen. Pedrosia (R. Lowe) Brand (Leguminosae).- Mitt. Bot. Staatssamml. München., 28, 513-567.

SANDRAL G., REMIZOWA M.V. and SOKOLOFF D.D. 2006. A taxonomy survey of Lotus

section Pedrosia (Leguminosae, Loteae). Wulfenia, 13, 97-192. SOKOLOFF D.D. and LOCK J.M. 2005. Loteae. In LEWIS G., SCHRIRE B., MACKINDER B.

and LOCK M. (Eds.). Legumes of the world. BATH Press: United Kingdom. pp. 455-466.



Lotus genetics and genomics: Resources and approaches

JENS STOUGAARD*, NIELS SANDAL, NIELS JØRGENSEN, SVEND DAM, GITTE NAUTROP, JAKOB FREDSLUND, BIRGIT K. HOUGAARD, SIMONA RADUTOIU, LEILA TIRICHINE, LENE H. MADSEN, ESBEN B. MADSEN, YOKOTA KEISUKE, PALOMA ROMERO, ANNA JURKIEWICH, ANITA ALBREKTSEN, ESBEN M.H. QUISTGAARD and EIGO FUKAI. Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10, DK-8000 Aarhus, Denmark. * Corresponding author The molecular genetics of Lotus is focused on three diploid species: Lotus japonicus, Lotus filicaulis and Lotus burttii. In addition to the inbred germplasm of these species a resource of recombinant inbred lines has also developed from L. filicaulis x L. japonicus ecotype Gifu, from L. japonicus ecotype Gifu x L. burttii and from L. japonicus ecotype Gifu x L. japonicus ecotype MG20. In parallel several methods for genetic analysis of gene function have been established within the Lotus community. Insertion mutagenesis with T-DNA, transposable elements and retrotransposons have all been used in Lotus japonicus and an EMS mutagenesis machine for reverse genetics has been established at the John Innes Centre. To enable map-based cloning genetic maps are constructed and different methods for positional cloning of symbiotic loci are currently applied in order to clone genes involved in nodule initiation, nodule function as well as autoregulation (Tirichine et al., 2006). At the Kazusa DNA Research Institute the genome of the model Lotus japonicus is under sequencing and the complete sequence of substantial parts of the genome is already available in public databases. The sequencing program is focused on gene rich regions and an approach using seed points anchoring sequences onto the genetic map has been developed. Taking advantage of the available genome and EST sequences a proteomic program has been initiated on seed proteins and a transcriptome analysis based on Affymetix will soon be available. A summary of the structural and functional genomics within the Lotus community and the future perspectives will be given together with a discussion of the possibilities for transfer of information into cultivated legumes (Fredslund et al., 2006). References TIRICHINE L., IMAIZUMI-ANRAKU H., YOSHIDA S., MURAKAMI Y., MADSEN L.H., MIWA

H., NAKAGAWA T., SANDAL N., ALBREKTSEN A., KAWAGUCHI M., DOWNIE A., SATO S., TABATA S., KOUCHI H., PARNISKE M., KAWASAKI S. and STOUGAARD J. 2006. Deregulation of a Ca2+/calmodulin-dependent kinase leads to spontaneous nodule development. Nature, 441, 1153-1156.


Lotus genomics 55

FREDSLUND J., MADSEN L.H., HOUGAARD B.K., NIELSEN A.M, BERTIOLI D., SANDAL N., STOUGAARD J. and SCHAUSER L. 2006. A general strategy for the development of anchor markers for comparative genomics in plants. BMC Genomics, 2006, 7, 207.

Lotus Newsletter (2007) Volume 37 (2), 56.


Genetic resources of forage legumes for agriculture-pastoral

system in Uruguay MÓNICA REBUFFO*1, RODRIGO ZARZA1, OMAR BORSANI2, ESTEBAN CASARETTO2, ALVARO MESSA1, MARIA M. SAINZ2, RODRIGO SALDIAS1, ROSARIO ALZUGARAY1, FEDERICO CONDÓN1, PEDRO DIAZ2, JORGE MONZA2, DIEGO RISSO1, MARIA BEMHAJA1, RAUL BERMUDEZ1, WALTER AYALA1, NORA ALTIER1, MAURO ZARZA1. 1 Instituto Nacional de Investigación Agropecuaria (INIA), INIA La Estanzuela, Colonia, Uruguay 2 Laboratorio de Bioquímica. Departamento de Biología Vegetal. Facultad de Agronomía. Av. E. Garzón 780. CP 12900. Montevideo, Uruguay. * Corresponding author click here for Spanish version Animal production in Uruguay is limited by the productivity and quality of natural pastures that represent more than 70% of the grazing area. Temperate forage legumes have been adopted since the 60, particularly in intensive systems with cereal - perennial pastures rotations. Forage legumes are important in the sustainability of agricultural systems and natural ecosystems, with increments of up to 8 folds in the organic matter of agricultural rotations compared with monoculture systems. However, the low proportion of cultivated pastures reflects the difficulties in the establishment and persistence of introduced legumes. The main cultivated legumes in rotation with cereals are Lotus corniculatus (LC), Trifolium repens (TR) and T. pratense (TP), while L. subbiflorus (LS) and more recently L. uliginosus (LU) are sown in natural pastures. The wide utilization of LC, LS, LU, is due to their adaptation to soils with low P availability and the presence of tannins that diminish bloat occurrence in cattle. The production of perennial legumes is limited by several environmental restrictions (drought and flooding, acid soils, diseases and pests), even in the adapted species. An additional restriction in Uruguay is the incompatibility of rhizobia strains between species of the same genus. Strains of LC are parasitic in LS and LU; similar incompatibility takes place with the introduction of TR or TP in areas with T. polymorphum, a perennial native species. Plant breeding (PB) during the last decade has concentrated on Lotus and Trifolium whose distribution varies with soil and climatic conditions. The collection of landvarieties increases the possibility to generate differences due to natural selection, through the adaptation to specific edaphic and climatic conditions. The strategy to evaluate those differences is centered in the use of biochemical, physiologic and genetic markers. Naturalized populations have been used in the past in PB (LC cv INIA Draco, a cultivar more persistent and tolerant to short periods of drought in the summer). Farmers’ participation in collection and characterization of LC and TP assures a quick adoption of the generated products (Project LESIS - FONTAGRO FTG 787/2005). The integration of a multidisciplinary team carries out the research for water stress in the genus Lotus (Project LOTASSA - FP6-2003-INCO-DEV2 PL-517617). Research advances in breeding of LC and TP are described during the presentation.

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Lotus Newsletter (2007) Volume 37 (2), 57 – 58.


Genetic resources and agropastoral systems in Chile

HERNAN ACUÑA*

Instituto de Investigaciones Agropecuarias, CRI Quilamapu. Chillán, Chile * Corresponding author click here for Spanish version Three Lotus species known as high value forage plants are present in Chile, L. corniculatus (Lc), L. glaber (Lg) and L. uliginosus (Lu). There is no record of the date of their introduction in the country but it would have happened in the first half of the twentieth century. Today these species are naturalized in specific environments between 32° and 38° S latitude. Lc is cultivated, but its spontaneous propagation is limited. Lg and Lu are broadly distributed in mediterranean and southern humid climates, on neutral to moderately acidic and acidic soils, respectively. One Lc cv. originated in Chile is available, Quimey. During recent years the performance of 12 cvs., from north and south-America and Australia, has been evaluated in Chile compared to Quimey (Acuña et al.,2002a). A naturalized germplasm collection of Lg (11 accessions) and Lu (21 accessions) was characterized for agronomic trait in different environments within the distribution area of each species is available (Acuña et al., 2002b). The Lg accessions differ in plant hight, phytomass production and N-fixation rate but show similar concentrations of condensed tannins (CT) in herbage (lower than Lc and Lu). The Lu germplasm is in general of postrate growth habit contrasting with the semierect New Zealand cv. Maku, but there are differences in plant hight among accessions. They differ in fitomass production, N-fixation rate and CT concentration in most of the environments. The Lg and Lu germplasm concentrate the herbage production in spring more than Lc, but both species have accessions with an acceptable equilibrium between the spring and summer production. These species are well adapted to soil with limitations as texture, depth, acidity or Al toxicity and deficiencies of P, K, S and other elements, as well as to water deficit caused by water shortage for irrigation or low rain condition. When the Lg and Lc are the pasture´s (natural or sown) basic legumes, which improves N plant nutrition and forage quality, they are mainly used in beef cattle production systems. This occurs in rice crop areas where lotus use the land for two or three years in rotation with the cereal, and in volcanic soil areas with irrigation water restrictions and in sandy soil areas with water table near surface, all of them located in the Central –South zone of the country (potential: 500.000 ha). In the humid zone of Southern Chile there are extensive areas of acidic soils with high levels of Al saturation and P deficiencies where Lu is broadly distributed and plays an important role in beef cattle production (potential: 1000.000 ha). On average, these kind of pastures produce 8 to 10 tons of DM per ha/year and the live weight yield is around 350 to 500 kg per ha /year, depending on the zone and the production phase – growing or finishing.

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58 H. Acuña

References ACUÑA P.H., FIGUEROA M., DE LA FUENTE A., ORTEGA F., y FUENTES C. 2002a.

Comportamiento de cvs. de Lotus corniculatus L. en diferentes ambientes de la VIII y IX Regiones de Chile. [Performance of cvs of Lotus corniculatus L. in different environments of the VIII and IX regions of Chile] Agro-Ciencia, 18(2), 75-84. [Spanish]

ACUÑA P. H., FIGUEROA M., DE LA FUENTE A., ORTEGA, F., SEGUEL I. y MUNDACA R.

2002b. Caracterización agronómica de accesiones de Lotus glaber Mill. y Lotus uliginosus Schkur. naturalizadas en Chile. [Agronomic characterization of accessions of Lotus glaber Mill. and Lotus uliginosus Schkur. Naturalized in Chile] Agro-Ciencia, 18(2), 63-74. [Spanish]



Legume Utilization in Grazing Systems in Southern Brazil MIGUEL DALL’AGNOL*1 and SIMONE M.S. BASSO2.

1Universidade Federal do Rio Grande do Sul, Brasil, bolsista CNPq. 2Universidade de Passo Fundo, bolsista CNPq. * Corresponding author click here for Portuguese version The Brazilian subtropical region is limited northwise by the Tropic of Capricorn (24 o S) and in the south by the extreme south of the state of RS, which borders Uruguay. Despite this political limitation, the “Campos” area, in a broad sense, at the southern cone of South America, encompasses an area of about 45million of ha with an enormous potential of improvement and utilization. The natural pastures are still the most important forage resource for animal production in the Brazilian subtropics. In the case of the state of RS, the initial participation of the native pastures, that was of about 60% of all of the area, decreased to about 10,5 million in 1995/96 and it is calculated today in less than 8 million of ha, in its majority substituted by summer crops (soybeans, maize and rice), fruits (specially with temperate species) and more recently by the aggressive advance of forestry (Pinnus, Eucalyptus and Acacia). Despite all of this, this entire region could potentially be improved by the introduction of temperate legumes due to its high forage value. The use of cultivated temperate pastures of winter is also a good alternative to compose integrated crop-grazing systems, since from the total area of approximately six million of ha cultivated with summer crops in the state, only 12% are cultivated with wheat or other cultures in the winter, being the rest rarely used (CONAB, 2007). This clearly indicates the great potential of use of winter pastures that we have and that are not used, especially if legumes are incorporated to the production systems. Despite its recognized importance, the use of legumes in practically all the grazing systems is very limited. Although the legumes are extremely important species in any system of utilization, its lack of persistence has been pointed as the biggest limitation to its use and inadequate practices of management have been considerate as the main cause of this failure at the level of the farmers. (Beuselinck et al., 1994). Rochon et al.,(2004) consider that the benefits provided by the use of legumes partially are counterbalanced, in tempered regions as well as in the Mediterranean regions, due to the difficulties in the establishment, maintenance and management under grazing. Therefore, it seems clear that, although the innumerable benefits of the use of legumes, its lack of persistence has been an important factor that has limited the expansion of its use in different regions. In global terms, recent data (Shelton et al., 2005) indicate that, in Brazil, only around 2% of its 130 million of ha of cultivated tropical pastures possess some participation of legumes. In the Southern of Brazil, even though reliable estimates are not available, the picture is not very different. Therefore, it seems important that, at this moment, the causes of the small use of legumes in grazing systems be studied and understood, and it is important as well to have a re-study of the potential areas of use and the benefits from them. In this context, one of the important temperate groups of forage species is the genus Lotus. The genus Lotus possesses more than 170 species, presenting varied forms of growth, and cycles

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of life, distributed throughout different climatic regions. Amongst these species one of the most important for the south region of Brazil is the Lotus corniculatus. Hopkins et al. (1996) reported that the pastures formed with Lotus can play a significant role in situations in which fertilizers and the management, necessary to support fertilized grasses with N or mixed with white clover, cannot be justified by economic or environmental reasons. Despite all this potential, Brazil possesses only one cultivar commercially available, a material that was developed and released in the decade of 1960, lacking, therefore, a more modern germoplasm, with superior characteristics. Compared with other tempered species, the bidsfoot trefoil is a much less demanding species in soil fertility, demanding a lower amount of inputs, although it requires more care about management related to frequency and intensity of utilization. Moreover, it is a species very well adapted to most of our climatic conditions, presenting an excellent natural reseeding and not causing bloating to the animals. Despite these advantages, its use in production systems has been very limited and its lack of persistence for long periods also has been observed, mainly due to problems of management and the presence of diseases. Therefore, the possibilities of use of legumes with proven forage potential and that require less amount of inputs should be stimulated and at the same time we should try to understand the reasons for its low use. Moreover, some native species, as for example, those that belong to the genus Trifolium, Adesmia, and Desmodium, whose productive potential have been indicated many years ago, and that are also species with less requirements in terms of soil fertility, must also be present in the evaluation programs and breeding programs of all research institutions, at least in the public ones. Currently, due to the pressure imposed by the expansion of crop areas, the areas of pastures have been dislocated to marginal areas, in degraded soils with low fertility. As a consequence of this, the pastures have been constantly defied in their adaptative capacity to the different conditions of stress, as salinity, alkalinity, drought, acidity, amongst others, generating frustrating results. Therefore, an alternative would be the use of species that already possess some degree of tolerance to these stresses or even the improvement of species, aiming at the adaptation in these stressful environments. Since many years, the traditional concept of, adapting the environment to the plant, in accordance with its requirements has shown its incapacity to deal with the problem, especially in developing countries. Therefore, a new alternative is been seeked for many years, that is, to adapt the plant to the stressful environment, always remembering that minimum levels of production are necessary to reach sustainable levels of production. That is, some amount of inputs must be added, even to the plants that are considered tolerant or adapted, otherwise, zero input, generally results in zero output! (Sanchez and Salinas, 1981). References BEUSELINCK P.R. (Ed.) 1999. Trefoil: the science and technology of the Lotus. Madison,

CSSA, 267pp BEUSELINCK P.R., BOUTON J.H., LAMP W.O., MATCHES A.G., MCCASLIN M.H., NELSON

C.J., RHODES L.H., SHEAFFER C.C., and VOLENEC J.J. 1994. Improving legume persistence in forage crops systems. Journal of Production Agriculture, 7, 311-322.

Temperate forage legumes in Brazil 61

CONAB. Produção Agropecuária: Safra de grãos 2006/2007. Disponível www.conab.gov.br/conabweb. Acesso em junho de 2007.

HOPKINS A., MARTYN T.M. JOHNSON R.H. SHELDRICK R.D. and LAVENDER R.H. 1996.

Forage production of two Lotus species as influenced by companion grass species. Grass and Forage Science, 51, 343-349.

ROCHON J.J., DOYLE C.J., GREEF J.M., HOPKINS A., MOLEE G., SITZIA M., SCHOLEFILED

D., and SMITH C.J. 2004. Grazing legumes in Europe: a review of their status, management, benefits, research needs and future prospects. Grass and Forage Science, 59, 197-214.

SANCHEZ J.G. and SALINAS P.A. 1981. Low-input technology for managing oxisoils and

ultisoils in tropical America. Advances in Agronomy, 34, 279-406 SHELTON H.M., FRANZEL S. and PETERS M. 2005. Adoption of tropical legume

technologies around the world: analysis of success. In: MC GILLOWAY D.A. (Org.). Grassland: a global resource, Wageningen, p.149-166.

http://www.conab.gov.br/conabweb



Biodiversity of Lotus spp. in Devesa of lÀlbufera (Valencia,

Spain) FRANCISCO ESCARAY1, AGUSTINA SCAMBATO1, PACO COLLADO ROSIQUE2, ANTONIO VIZCAINO MATARREDONA2, JOSEP ROSELLO PICORNELL3, MARCELA ROSATO3, CARMEN ANTOLÍN TOMÁS4, PEDRO CARRASCO SORLI5 and OSCAR A. RUIZ1* 1 IIB-INTECh; UNSAM-CONICET CC 164 (7130) Chacomús, Argentine. 2 Devesa-Albufera Service of Ayuntamiento de Valencia (Spain). 3 Jardí Botànic, Universitat de València (Spain). 4 CIDE (Centro Investigación Desertificación). Universitat de València (Spain). 5 Director del Departament de Bioquímica i Biología Molecular. Universitat de València (Spain). * Corresponding author click here for Spanish version The Devesa of lÀlbufera is an area of “restinga” of the Natural Parq of lÀlbufera (Valencia, Spain), in which four ecosystems are present as strips parallel to the sea: the beach, movable dunes or first cord of dunes, “malladas” and fixed dunes. The extreme environmental conditions typical of the Devesa (soil dryness, low organic matter content and high permeability, action of the marine wind and constant mobility of the substrate) determine the presence of a particular type of vegetation (Benavent et al. 2004). Predominating soil types are the Calcaric Arenosols, although in the “malladas”, which exhibit greater hydromorphism, Calcaric Gleysols or Gleyic Solonchaks can be found, the latter having high salinity levels (FAO-UNESCO classification, 1988; Rubio Delgado et al. 1998). This system of dunes constitutes an ecosystem of great ecological value, but unfortunately it was quite modified during the Urban Developing Plan onset around 45 years ago, as a result of which, the beach and front dune cord were the most affected sectors. Since 1980, the Technical Office Devesa-Albufera (OTDA) is in charge of the management of the natural spaces of Valencia and one of its high-priority objectives is the restoration of the first dune front. This process consists of three stages: restoration of dune morphology by means of mechanical sand accumulation, dune fixing by construction of fences and plantation of native psamophile species and, finally, the adaptation of the area recovered for public use. One of the species used for dune plantation is the native legume Lotus creticus L., a typical component of the vegetal associations Medicago marinae-Ammophiletum arundinaceae Br.-Bl. (1931) 1933 and Crucianelletum maritimae Br.-Bl. (1931) 1933. The distribution and relation of L. creticus with other vegetal species was studied and it was found to be associated with other psamophile species (Elymus farctus, Otanthus maritimus, Ammophila arenaria and Malcolmia littorea) in movable dunes (Costa and Mansanet, 1981). Also, by means of the linear interception method, cover by L. creticus and the other two legumes present (Medicago marine L. and Ononis natrix L.) was evaluated in three sectors of the first dune-front. L. creticus was the legume showing greater cover and reached its maximum

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Dunes restoration at Valencia 63

value in the windward sector and crest of the primary dune. Cover by L. creticus gradually decreased when approaching to the fixed dunes, being minimum or null in the woody plant communities. On the other hand, the “malladas” are another type of ecosystem present in the Devesa, which are located in the depressions between dunes. Soils in the “malladas” are muddy, with variable salinity levels and become flooded as a consequence of rain. In zones of medium salinity that conserve certain degree of humidity throughout the year, the vegetal alliances developed are Juncion maritimi Br.-Bl. 1931 and Plantaginion crassifoliae Br.-Bl. 1931, to both of which a Lotus species was associated. This species was described in the literature to be Lotus corniculatus crassifolius (2n=24) (Grant, 1995). However, chromosomal counts performed in our laboratory found it to have 2n=12. The location of populations of this species within the Devesa was determined and the conductivity of soils in which they are developed was analyzed and found to be very variable (0.2 to 13.0 ds/m). Finally the biodiversity study was completed by taking samples of L. creticus plants for the analysis of root colonization by mycorrhyzal fungi and the isolation of rhizobia from root nodules of both Lotus species, which are currently being characterized. References BENAVENT OLMOS J.M., COLLADO ROSIQUE P., MARTÍ CRESPO R.M., MUÑOZ

CABALLER A., QUINTANA TRENOR A., SÁNCHEZ CODOÑER A y VIZCAINO MATARREDONA A. 2004. La restauración de las dunas litorales de la Devesa de l`Albufera de Valencia. Ajuntament de Valencia. 65 p. [http://www.albufera.com].

COSTA M. y MANSANET J. 1981. Los ecosistemas dunares levantinos: la Dehesa de la

Albufera de Valencia. [The dunar ecosystems: the “Dehesa de la Albufera” of Valencia]. Actas III Congreso Optima. Anales Jardín Botánico Madrid, 37 (2), 277-299. [Spanish].

FAO-UNESCO. 1988. Soil Map of the World. Revised Legend FAO. Roma. GRANT W.F. 1995. A chromosome atlas and interspecific-intergeneric index for Lotus and

Tetragonolobus (Fabaceae). Canadian Journal of Botany 73, 1787-1809. RUBIO DELGADO J.L., ANDREU PÉREZ V. y SANCHIS DUATO E. 1998. Los suelos de la

Devesa de la Albufera. [The soils of Devesa de la Albufera]. Revista Valenciana d´Estudis Autonòmics, 22, 129-144. [Spanish]



Evolution in insular Mediterranean Lotus. What we know and

what should be known JOSEP A. ROSSELLÓ*

Jardín Botánico, Universidad de Valencia, c7Quart 80, E-46008 Valencia, Spain. * Corresponding author click here for Spanish version The Mediterranean basin is one of the hot-spots of diversification of Lotus. Recent studies using nuclear ribosomal markers have clarified generic delimitations and phylogenetic relationships with the related Tetragonolobus and Dorycnium. However, documented patterns of intraspecific variation concerning karyological and molecular markers are scanty. In this talk we provide molecular evidence documenting patterns of reticulate hybridization in sympatric populations of Lotus from the Balearic Islands (Lotus dorycnium and Lotus fulgurans). Nuclear markers from ribosomal ITS sequences suggest asymmetric gene flow between widespread, non-endangered species and endemic species. Contrary to expectations, asymmetric pollen flow is from the rare species to the widespread one. Patterns of chloroplast and nuclear variation at pseudogenized loci suggest the presence of a clear phylogeographic scenario in these continental islands.

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Current status and uses of the endemic Lotus to the Canary

Islands.

JUAN RAMÓN ACEBES GINOVÉS1* and FELICIA OLIVA TEJERA2

1Departamento de Biología Vegetal (Botánica). Facultad de Farmacia. Universidad de La Laguna. 38072 La Laguna. Tenerife. Islas Canarias. España. 2Jardín Botánico CanarioViera y Clavijo, Ap. de correos 14 de Tafira Alta, 35017 Las Palmas de Gran Canaria, Gran Canaria, Islas Canarias, España. * Corresponding author click here for Spanish version The genus Lotus in the Canary Islands is represented by 24 species, being seventeen of them endemic (Acebes et al., 2004). According to other authors (Sandral et al., 2006) the number is lesser (14 species and some infraspecific taxa). They are included in several sections o subgenera depending on the taxonomic view of diverse authors. The Canary endemic Lotus, including L. glaucus and L. lancerottensis which are also present in Madeira, are included in two taxa: Sect. Pedrosia (Lowe) Christ or subgen. Pedrosia (Lowe) Brand and subgen. Rhyncholotus Monod or sect. Rhyncholotus (Monod) Sokoloff. The non endemic species are included in some infrageneric taxa. Regarding to the taxonomic treatment of sect. Pedrosia the publication of Sandral et al. (2006) has produced several taxonomical changes. The main changes are: L. glaucus is considered endemic to Madeira and Salvagen Islands, and consequently not represented in Canary Islands (although they mention a record for L. glaucus s.l. to Fuerteventura, as a possible synonym of L. erythrorhizus Bolle). The records of L. glaucus mentioned for Canaries are now considered to belong to L. tenellus (Lowe) Sandral, Santos & Sokoloff. Major changes are made in the group of the typical Lotus of the Canary pine woodland: L. holosericeus Webb & Berthel. is included as synonym of L. spartioides Webb & Berthel, an endemic taxon of the Gran Canaria pine woodland. L. hillebrandii Christ, endemic of La Palma, is included as a subspecies of L. campylocladus Webb & Berthel., and the type subspecies remain as endemic of Tenerife. Currently Felicia Oliva Tejera is carrying out the studies of her PhD in our Department at the University of La Laguna in collaboration with the Botanical Garden “Viera y Clavijo” of Las Palmas de Gran Canaria which is entitled “Morphological and molecular studies of the endemic Canary Lotus (Fabaceae: Loteae) of the pine woodland”. The first results of the mollecular (isoenzymes) and morphological studies (Oliva Tejera, 2006) indicate that L. holosericeus, an endemic of the south pine woodland of Gran Canaria, is different to L. spartioides, an endemic of the north and northwest pine woodland of that island. The infraspecific status of L. hillebrandii is also considered. We do not know other different use that ornamental for the Canary Lotus although could be used as a fodder. Mainly Lotus section Rhyncholotus, commonly called “picos de paloma” are used for such purpose. We think they could play a role in the soil conservation in arid, semiarid and dry areas, ranging from pine woodland to the coast in the Canary Islands.

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References ACEBES GINOVÉS J.R., ARCO AGUILAR M. DEL, GARCÍA GALLO A., LEÓN ARENCIBIA

M.C., PÉREZ DE PAZ P.L., RODRÍGUEZ DELGADO O., WILDPRET DE LA TORRE W., MARTÍN OSORIO V.E., MARRERO GÓMEZ M.C. and RODRÍGUEZ NAVARRO M.L.. 2004. División Spermatophyta. In IZQUIERDO I., MARTÍN J.L, ZURITA N. and ARECHAVALETA M. (eds.) Lista de especies silvestres de Canarias (hongos, plantas y animales terrestres) 2004. Consejería de Política Territorial y Medio Ambiente. Gobierno de Canarias. p: 99-140.

OLIVA-TEJERA F., CAUJAPÉ-CASTELLS J., NARANJO-SUÁREZ J., NAVARRO-DÉNIZ J.,

ACEBES-GINOVÉS J.R. and BRAMWELL D. 2005. Population genetic differentiation in the taxa of Lotus (Fabaceae: Loteae) endemic from the Gran Canarian pine forest. Heredity, 94(2), 199-206

OLIVA-TEJERA F., CAUJAPÉ-CASTELLS J.J., NAVARRO-DÉNIZ J., REYES-BETANCORT A.,

SCHOLTZ S., BACCARANI-ROSAS M. and CABRERA-GARCÍA N. 2006. Patterns of genetic divergence of three Canarian endemic Lotus (Fabaceae:) : implications for the conservation of the endangered L. Kunkelii. American Journal of Botany, 93(8), 1116-1124.

SANDRAL G., REMIZOWA M.V. and SOKOLOFF D. 2006. A taxonomic survet of Lotus

section Pedrosia (Leguminosae, Loteae). Wulfenia 13: 97-102.



Río de la Plata grasslands and Lotus tenuis

ROLANDO J.C. LEÓN*, GUSTAVO STRIKER, PEDRO INSAUSTI and SUSANA B. PERELMAN

IFEVA – CONICET, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, CP1417DSQ Buenos Aires, Argentina.

* Corresponding author click here for Spanish version Temperate subhumid grasslands, in the eastern part of South America, cover the vast plains of central-eastern Argentina, Uruguay and southern Brazil. This grassland region can be divided into two subregions: (1) the pampas, in Argentine and (2) the campos of Uruguay and Southern Rio Grande do Sul (Brazil) (Soriano, 1991). In the Pampas, some of the areas have seldom or never been cultivated. Grazing has been the only modifying agent in these areas, which are mostly in low-lying locations of the flooding Pampa, the western portion of the Pampa (Soriano, 1991). In the flooding Pampa, the natural grasslands and pastures constitute the basis of cattle breeding. These grasslands show a great floristic heterogeneity in which herbaceous plant communities are arranged forming intricate landscape mosaics (Burkart et al., 1990). Four major grasslands habitat types have been defined: mesophyte prairies (MP), humid prairies (HP), meadows (M) and halophyte steppes (HS) (Ghersa et al., 2007). In comparison to other grasslands in the world, these ones show a great proportion of exotic species: 10% within perennial grasses, 16% within annual grasses, 19% within perennial dicots and 55% within annual dicots. Native legumes in these communities are very scarce (7 species), the exotic ones are more numerous (14 species) and they are more significant in produced biomass (Ghersa et al., 2007). The species of the Lotus genus are of the most recent introduction. In the north of the region, in 1968, Lotus tenuis (Lotus glaber Mill.) showed different constancy values in each one of the communities: MP=8.6, HP=11%, M=8%, HS=1%. In recent evaluations carried out in 51 sites of two of such communities, considerable increases were registered in the presence of L. tenuis: from 4 to 99% in MP and from 4 to 50% in HS (Ghersa et al., 2007). In the south of the region the presence of this legume was already important 30 years ago: MP=8.5%, HP=34%, M=24% and HS=7% (Ghersa et al., 2007). The wide distribution of Lotus tenuis in the humid prairies and meadows is considered of great relevance for forage production. The reason behind such distribution is the high tolerance of L. tenuis to long-term flooding, one of the major disturbances affecting these plant communities. In experiments carried out in these communities we have advanced in the identification of anatomical, morphological and physiological attributes conferring to L. tenuis tolerance to the lack of oxygen due to the flood (Striker et al., 2005). In this sense, we have found that the flooded plants of L. tenuis increase the porosity notably in the stems (porosity 13%) and roots (porosity 28%), they locate a high proportion of their leaves above the water level (53%) and they can maintain unaffected their stomatal conductance and photosynthesis for more than three weeks (Striker et al., 2005). These responses tend to facilitate the capture and transport of oxygen to roots and maintain carbon fixation and biomass production under flooding conditions. Besides,


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68 R.J.C. León, G. Striker, P. Insausti and S.B. Perelman

we have studied the interaction between flooding and trampling, an unavoidable sequel of cattle grazing (Striker et al., 2006). In this sense, we found that the roots of L. tenuis possess a low mechanical resistance (250 KPa) with relationship to the pressure that can generate on them the hoof of a cow (>300 KPa) (Striker et al., 2006), in consequence their plants are much damaged when both disturbances are combined. This aspect should be taken into account for grassland management. References BURKART S.E., LEÓN R.J.C. and MOVIA C.P. 1990. Inventario fitosociológico del pastizal

de la Depresión del Salado (Prov. de Bs. As.) en un área representativa de sus principales ambientes. Darviniana, 30, 27–69.

GHERSA C.M, PERELMAN S.B., BURKART S.E. and LEON R.J.C. 2007. Floristic and

structural changes related to opportunistic soil tilling and pasture planting in grassland communities of the Flooding Pampa. Biodiversity and Conservation, 16, 1575-1592.

SORIANO A. 1992. Río de la Plata Grasslands. Ecosystems of the world 8A. COUPLAND R.T.

(ed.) Natural grasslands. Introduction and Western Hemisphere. Elsevier, Amsterdam. pp. 367–407.

STRIKER G.G., INSAUSTI P., GRIMOLDI A.A., PLOSCHUK E.L. and VASELLATI V. 2005.

Physiological and anatomical basis of differential tolerance to soil flooding of Lotus corniculatus L. and Lotus glaber Mill. Plant and Soil, 276, 301-311.

STRIKER G.G., INSAUSTI P., GRIMOLDI A.A. and LEON R.J.C. 2006. Root strength and

trampling tolerance in the grass Paspalum dilatatum and the dicot Lotus glaber in flooded soil. Functional Ecology, 20, 4–10.



Germinative response of Lotus creticus to different temperatures

and salinity conditions CARMEN LÓPEZ VALIENTE *1, ELENA ESTRELLÉS1, PILAR SORIANO1 and JESÚS PICÓ2

1 ICBiBE. Botanic Garden, University of Valencia, Quart 80, 46008 Valencia, SPAIN 2 Dept. of Systems Eng. & Control, Technical University of Valencia, Camí de Vera 14, 46022 Valencia, SPAIN * Corresponding author click here for Spanish version The flora at the coastal dunes ecosystems in the Valencian Community has a great biological interest. These ecosystems are suffering in the last decades a strong harassment and urban pressure, leading to their massive and continuous destruction. Therefore, all studies towards the knowledge of the vegetal species living in these dunes, and their conservation, are of great interest (Harris and Davy, 1986; Jusaitis et al., 2004; Carter and Ungar, 2004). The dunes cords are important, for they receive the direct impact of wind protecting the ecosystems placed behind. Dunes plants are specialized as a function of their proximity to the seacoast. Factors most influencing this specialization are the soil mobility, salinity (Katembe et al., 1998; Gulzar and Khan, 2001; Debez et al., 2004), abrasive effect of wind and low retention of water in sandy soils (Khan and Ungar, 1984; Khan et al., 2000; Zia et al., 2004). The distribution of the species in the different areas of the dunes results from their physiological requirements and their interaction with other species (Costa et al., 1982). Thus, Lotus creticus belongs to the association Medicagini mariane-Ammophiletum australis, found in the embryonic dunes and in those in movement. The aim of the study performed was to find the values of temperature and salinity leading to optimal germination. To this end, scarified seeds were germinated in Petri dishes during one month. A wide set of temperature and salinity conditions were applied. The percentage of germinated seeds is close to 100% in all the conditions studied, with very low variance, with the exception of the extreme conditions corresponding to the alternating temperatures 40º/20ºC, and the low constant temperature 10ºC. The same trend is observed in the velocity of germination. With the exception of the extreme conditions mentioned, there is a high correlation between the percentage of germination and its velocity. Though Medicago marina is the representative plant in the association Medicagini mariane-Ammophiletum australis, Ammophila arenaria the dominant, and Lotus creticus an accompanying one, it turns out that it presents higher velocities of germination than M. marina in a wider range of conditions. Thus, for instance, Lotus creticus covers the void left by M. marina in extreme conditions. Concerning tolerance to different salt concentrations, a high percentage and velocity of germination is observed at 100mM. At 200 mM the percentage of germination remains high, yet the velocity of germination decreases notably. At higher salt concentrations both percentage and velocity of germination are very low. More details about the experimental conditions, indices used, and results obtained will be presented complementary.

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References CARTER C.T and UNGAR I.A. 2004. Relationship between seed germinability of Spergularia

marina (Caryophyllaceae) and formation of zonal communities in an inland salt marsh. Annals of Botany. 93, 119-125.

COSTA M.J., PERIS J.B., y FIGUEROLA R. 1982. La vegetación de la devesa de La Albufera

de Valencia. [The vegetation of La devesa de La Albufera de Valencia] Dpto. Botánica, Facultad de Farmacia, Universitat de València. Delegación del Medi Ambient i Espais Oberts. Ayto de Valencia. [Spanish Monography] 87 pp.

DEBEZ A., HAMED K.B., GRIGNON C. and ABDELLY C. 2004. Salinity effects on

germination, growth, and seed production of the halophyte Cakile maritime. Plant and soil, 262, 179-189.

GULZAR S. and KHAN M.A. 2001. Seed germination of a halophytic grass Aeluropus

lagopoides. Annals of Botany, 87, 319-324. HARRIS D. and DAVY A.J. 1986. Regenerative potential of Elymus farctus from rhizome

fragments and seed. Journal of Ecology, 74, 1057-1067. JUSAITIS M., POLOMKA L., SORENSEN B. 2004. Habitat specificity, seed germination and

experimental translocation of the endangered herb Brachycome muelleri (Asteraceae). Biological Conservation, 116, 251-266.

KATEMBE W.J., UNGAR I.A. and MITCHELL J.P. 1998. Effect of salinity on germination

and seedling growth of two Atriplex species (Chenopodiaceae). Annals of Botany, 82, 167-175.

KHAN M.A. and UNGAR I.A. 1984. The effect of salinity and temperature on the

germination of polymorphic seeds and growth of Atriplex triangularis Willd. American Journal of Botany, 71, 481-489.

KHAN M.A., GUL B. and WEBER D.J. 2000. Germination responses of Salicornia rubra to

temperature and salinity. Journal of Arid Environments, 45, 207-214. ZIA S. and KHAN M.A. 2004. Effect of light, salinity, and temperature on seed germination

of Limonium stocksii. Canadian Journal of Botany, 82, 151-157.



Primary and secondary nitrogen assimilation in Lotus japonicus

and the relationship with drought stress

ANTONIO J. MÁRQUEZ*1, MARCO BETTI1, MARGARITA GARCÍA-CALDERÓN1; ALFREDO CREDALI1, PEDRO DÍAZ2 and JORGE MONZA2 1 Departamento ed Bioquímica Vegetal y Biología Molecular, Facultad de Química, Universidad de Sevilla, C/ Profesor García González 1, 41071-Sevilla, España. 2 Departamento de Biología Vegetal, laboratorio de Bioquímica, Av. Garzón 780 CP12900 Montevideo, Uruguay * Corresponding author click here for Spanish version In our laboratories we carry out research on nitrogen assimilation in Lotus plants and the possible relationships with drought stress situations that become a likely cause of the loss of these forage plants when they are cultivated (Díaz et al., a, b). Some of our research has been conducted with the model legume Lotus japonicus, while other research was done on cultivated species. Lotus japonicus plants are able to use both nitrate and ammonium as inorganic nitrogen sources for ulterior assimilation, or, alternatively, they can also use atmospheric dinitrogen through Mesorhizobium loti symbiosis. Primary nitrate assimilation takes place predominantly in the roots of the plant, being strongly dependent on the age and limitation of space for root growth (Orea et al., 2001; Pajuelo et al., 2002). Attempts of genetic manipulation of root-shoot partitioning of nitrate assimilation, either by increasing external nitrogen availability (Orea et al., 2005a), or using a transgenic approach (Orea et al., 2005b), were not able to shift this partitioning to the aerial part of the plant, thus suggesting the existence of ecophysiological adaptations for a preferential use of external nitrogen in the root (Márquez et al., 2005). This situation makes crucially important the mobilization of nitrogen from roots to shoots of the plant, particularly with regard to asparagine metabolism. On the other hand, in our laboratory we have also recently shown the importance for this plant of other forms of secondary nitrogen assimilation such as reassimilation of ammonium released by photorespiration. We have used a mutagenesis approach to demonstrate the essentiality of plastidic glutamine synthetase in this process. However, this was not the case for primary ammonium assimilation, a process which can rely basically on cytosolic glutamine synthetase (Orea et al., 2002; Betti et al; 2006). There is also some influence of photorespiration on the level of different ammonium transporters (D'Apuzzo et al., 2004). Nitrogen metabolism in Lotus plants shows also a strong connection with drought stress situations, mainly through the biosynthesis of proline, which becomes a very nice marker of osmotic stress situations in this plant (Díaz et al., 2005 b,c). Proline metabolism is greatly influenced by the type of nitrogen nutrition provided to the plant (Díaz et al., 2005c). At present we are also investigating the possible interconnection between photorespiration and drought stress situations in these plants.

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72 A.J. Márquez, M. Betti, M. García-Calderón, A. Credali, P. Díaz and J. Monza

References BETTI M., ARCONDEGUY T. and MÁRQUEZ A.J. 2006. Molecular analysis of two mutants

from Lotus japonicus deficient in plastidic glutamine synthetase: functional properties of purified GLN2 enzymes. Planta, 224, 1068-1079.

D'APUZZO E., ROGATO A., SIMON U., ALAOUI H.E., BARBULOVA A., BETTI M., DIMOS

M., KATINAKIS P., MARQUEZ A.J., MARINI A., UDVARDI M.K. and CHIURAZZI M. 2004. Characterisation of three functional high affinity ammonium transporters in Lotus japonicus with differential transcriptional regulation and spatial expression Plant Physiology, 134, 1763-1774.

DIAZ P., BORSANI O. and MONZA J .2005a. Lotus-related species and their agronomic

importance. In MÁRQUEZ A.J. (Ed.) Lotus japonicus Handbook. Springer, The Netherlands, pp. 25-37.

DIAZ P., MONZA J. and MÁRQUEZ A.J. 2005b. Drought and saline stress in Lotus japonicus

In MÁRQUEZ A.J. (Ed.) Lotus japonicus Handbook. Springer, The Netherlands, pp. 39-50.

DIAZ P., BORSANI O., MÁRQUEZ A.J. and MONZA J . 2005c. Osmotically induced proline

accumulation in Lotus corniculatus leaves is affected by light and nitrogen source. Plant Growth Regulation, 46, 223-232.

MÁRQUEZ A.J., BETTI M., GARCÍA-CALDERÓN M., PALOVE-BALANG P., DIAZ P. and

MONZA J. 2005. Nitrate assimilation in Lotus japonicus. Journal of Experimental Botany, 56, 1741-1749.

OREA A., PAJUELO P., PAJUELO E., MÁRQUEZ A.J. and ROMERO J.M. 2001.

Characterisation and expression studies of a root cDNA encoding for ferredoxin-nitrite reductase from Lotus japonicus. Physiologia Plantarum, 113, 193-202.

OREA A., PAJUELO P., PAJUELO E., QUIDIELLO C., ROMERO J.M. and MÁRQUEZ A.J. 2002.

Isolation of photorespiratory mutants from Lotus japonicus deficient in glutamine synthetase Physiologia Plantarum, 115, 352-361.

OREA A., PROSSER I., ROMERO J.M. and MÁRQUEZ A.J. 2005a. Transgenic plants affected

in nitrate assimilation. In MÁRQUEZ A.J. (Ed.) Lotus japonicus Handbook. Springer, The Netherlands, pp. 329-340.

OREA A., PAJUELO P., ROMERO J.M. and MÁRQUEZ A.J. 2005b. Nitrate assimilation:

influence of nitrogen supply In MÁRQUEZ A.J. (Ed) Lotus japonicus Handbook. Springer, The Netherlands, pp. 329-340.

Nitrogen assimilation in Lotus and drought stress 73

PAJUELO P., PAJUELO E., OREA A., ROMERO J.M. and MÁRQUEZ A.J. 2002. Influence of plant age and growth conditions on nitrate assimilation in roots of Lotus japonicus plants. Functional Plant Biology, 29, 485-494.



Lotus tenuis as a keystone species for the Salado River Basin

(Argentine)

FERNANDO L. PIECKENSTAIN1, MARÍA J. ESTRELLA1, ANALÍA SANNAZZARO1, ANA MENÉNDEZ1, VANINA FRACAROLI1, NAZARENO CASTAGNO1, MARIELA ECHEVERRÍA1, JULIETA PESQUEIRA1, PATRICIO VERTIZ1, ROSALÍA PAZ1, MARÍA EUGENIA MICIELI1, FRANCISCO ESCARAY1, VERÓNICA BERGOTTINI1, SILVANA SCHULMEISTER1, PATRICIA UCHIYA1, BEATRIZ ROSSO2, ADRIANA ANDRES2 and OSCAR A. RUIZ1*

1 Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh) Camino de Circunvalación de La Laguna Km 5. Casilla de Correo 164 (B7130IWA) Chascomús. Provincia de Buenos Aires. Argentina. 2 Instituto Nacional de Tecnología Agropecuaria Estación Experimental Agropecuaria Pergamino, CC 31, (2700), Pergamino, Provincia de Buenos Aires, Argentina * Corresponding author click here for Spanish version Agricultural expansion to areas traditionally devoted to animal production in the Argentinean Pampas generates the need to increase forage production in restrictive environments and conditions. In order to improve pasture productivity, Lotus tenuis (=L. glaber Mill.) germplasm was collected, characterized and selected. L. tenuis is a perennial legume naturalized in saline-alkaline lowlands in the Salado River Basin, highly valuable because of its contribution to forage offer in the region and its influence on growth of associated species. For this reason, L. tenuis is considered as a “Keystone species”. Taking into account that L. tenuis is alogamous, it can be supposed that during naturalization, diverse ecotypes have developed different aptitudes to tolerate stress conditions typical of the region, including soil alkalinity and salinity, flooding and summer droughts, among others. In order to select for tolerant materials and to better understand the mechanisms involved in the response to salinity, different L. tenuis accessions were exposed to salinity under controlled conditions. Stress responses of the model species L. japonicus, Lotus burtii and Lotus filicaulis were also evaluated. Growth parameters, osmolites, ion (Na+, K+ and Ca++) and polyamine levels (Cuevas et al., 2004; Sanchez et al., 2005) were determined. L. tenuis and L. corniculatus transgenic lines harboring the oat arginine decarboxylase gene (coding for a key enzyme involved in polyamine biosynthesis) under the control of the stress inducible promoter RD29A have been obtained (Chieza et al., 2004) and their response to salinity is under evaluation at the present. In addition, the biodiversity of symbiotic microorganisms (rhizobia and vesicular arbuscular mycorrhizal fungi) associated to L. tenuis has been studied and the influence of these organisms on salt stress tolerance will be discussed (Estrella et al., 2007; Echeverría et al., 2006; Sannazzaro et al., 2004, 2006, 2007).

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Lotus tenuis under saline stress 75

References CHIESA, M.A., RUIZ, O.A. and SÁNCHEZ, D.H. 2004. Lotus hairy roots expressing inducible

arginine decarboxylase activity. Biotechnology Letters, 26, 729-733. CUEVAS J.C., SÁNCHEZ D.H., MARINA M. and RUIZ O.A. 2004. Do polyamines modulate

the Lotus glaber NADPH oxidation activity induced by the herbicide methylviologen?. Functional Plant Biology (ex-Australian Journal of Plant Physiology), 31, 921-928.

ECHEVERRÍA M., MARINA M., MENÉNDEZ A., MONTES M., RUIZ O.A., SANNAZZARO A.,

SCAMBATO A. and SOSA M. 2006. Plant polyamine metabolism and arbuscular mycorrhizal colonization. 5th International Conference on Mycorrhiza, Granada, España. 23-27 July 2006.

ESTRELLA M.J., CASTAGNO L.N., MUÑOZ S., CASSAN F., RUIZ O.A., OLIVARES J., SOTO

M.J. and SANJUÁN J. 2007. Evaluación taxonómica, simbiótica y fisiológica de simbiontes de L. tenuis para la formulación de inoculantes de alta calidad en la región de la Pampa Deprimida del Salado. Reunión Latinoamericana de Rizobiología – RELAR 2007. Los Cocos, Córdoba, Argentina. 25 – 28 Marzo 2007.

SÁNCHEZ D.H., CUEVAS J.C., CHIESA M.A. and RUIZ O.A. 2005. Free spermidine and

spermine content in Lotus glaber under long-term salt stress. Plant Science, 2, 541-546. SANNAZZARO A., ECHEVERRÍA M., EDGARDO A., RUIZ O.A, and MENÉNDEZ A. 2007.

Modulation of polyamine balance in Lotus glaber by salinity and arbuscular mycorrhiza. Plant Physiology and Biochemistry, 45, 39-46.

SANNAZZARO A., RUIZ O. A., ALBERTÓ E. and MENÉNDEZ A. 2004. Presence of different

arbuscular mycorrhizal infection patterns in Lotus glaber growing in the Salado River Basin. Mycorrhiza, 14, 139-142.

SANNAZZARO A., RUIZ O.A, ALBERTÓ E. and MENÉNDEZ A. 2006. Lotus glaber salt stress

alleviation by Glomus intraradices. Plant and Soil, 285, 279-287.



Saline stress tolerance in legumes

CARMEN LLUCH*, NOEL TEJERA, JOSÉ A. HERRERA-CERVERA, MIGUEL LOPEZ, JOSÉ R. BARRANCO-GRESA, FRANCISCO J. PALMA, MONICA GOZÁLVEZ, CARMEN IRIBARNE, EMILIO MORENO and ANTONIO OCAÑA. Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada. Campus de Fuentenueva s/n. 18071. Granada. * Corresponding author click here for Spanish version The economic importance of legumes is related with their capacity to fix atmospheric nitrogen, thereby reducing agricultural cost through a reduction of fertilizer inputs and decreasing environmental contamination. The process of biological nitrogen fixation is present in many ecosystems and it is efficiency is determined by the environmental conditions. Saline stress is one of the main factors limiting legume productivity in arid and semi-arid regions affected by water or soil salinity, particularly when plant growth depends on symbiotic nitrogen fixation, since high salt concentrations in soil is also a negative factor for growth and activity of soil bacteria that establish symbiosis with legumes, collectively called rizobia (Asraf and Harris, 2004). The area of land affected by secondary salinity (salinity caused by human activity) is steadily increasing, with recent worldwide estimates that over 70 million ha of agricultural land is affected (FAO, 2005). Salinity impact on plants in two main ways: osmotic stress and ion toxicity (Munns, 2005). Osmotic stress is caused by ions (mainly Na+ and Cl-) in the soil solution decreasing the availability of water to roots. Ion toxicity occur when plant roots take up Na+ and/or Cl- and these ions accumulated to detrimental levels in leaves. Ion imbalances and nutrient deficiency, particularly for K+ nutrition, can be also occur (Tejera et al., 2006). The accumulation of compatible solutes in considered an adaptative response and therefore, molecular indicators of tolerance to salt stress and solutes should be studied within the highly specialized structures of legumes, the root nodules. The capacity of nodules to maintain a significant level of nitrogen fixation under salt conditions is determined by the energetic processes (nodule and bacteroid responses) and metabolic processes that lead to the export and import of photosynthesized and by the senescent processes. At the cellular level, the information on nodule and bacteroid metabolites, the enzymes involved in carbohydrate metabolism and enzymes required for assimilation of fixed nitrogen are essential to understand the consequences of saline stress on nodule functioning and therefore on the symbiosis. Salinity induces changes in the plant hormonal balance not only by the accumulation of ABA but also inducing a reduction of the levels of growth-activating hormones such as auxins and cytokinins. Ethylene and other growth regulators like salicylic acid play an important role in the response to salt stress (Glyan´ko et al., 2005) due to its ability to induce a protective effect on plant under stress. In addition, it has been reported the efficiency of pre-treatments with different phytohormones for restoration of metabolic alterations induced in some legumes by NaCl, such as Vicia faba, Vigna and Phaseolus vulgaris (Khadri et al., 2006). Recent research on high salinity responses in Medicago truncatula and Lotus japonicus implied that

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77

a large proportion of the genome is involved in high-salinity stress responses (Udvardi et al., 2007). Genome-wide identification of genes regulated by drought of high salinity conditions has manifold significance. References ASRAF M. and HARRIS P. J.C. 2004. Potential indicators of salinity tolerance in plants. Plant

Sciences, 166, 3-16. FAO 2005. Global network on integrated soil management for sustainable use of

salt-affected soils. FAO Land and Plant Nutrition Management Services, Rome Italy. http://www.fao.org/ag/agl/agll/spush.

GLYAN´KO A.K., MAKAROVA L.E., VASILÉVA G.G. and MORONOVA N.V. 2005. Possible

involvement of hydrogen peroxide and salicylic acid in the legume –Rhizobium symbiosis. Biology Bolletin, 32, 245-249

KHADRI M., TEJERA N.A. and LLUCH C. 2006. Alleviation of salt stress in common bean

(Phaseolus vulgaris) by exogenous abscisic acid supply. Journal of Plant Growth Regulation, 25, 110-119.

MUNNS R. 2005. Genes and salt tolerance: bringing them together. New Phytologist, 167,

645-663. TEJERA N.A., SOUSSI M. and LLUCH C. 2006. Physiological and nutritional indicators of

tolerance to salinity in chickpea plants growing under symbiotic conditions. Environmental and Experimental Botany, 58, 17-24.

UDVARDI M.K., KAKAR K., WANDREY M., MONTANARI O., MURRAY J., ANDRIANKAJA

A., ZHANG JI-YI., BENEDITO V., HOFER J.M.I., CHUENG F. and TOWN C.D. 2007. Legume Transcription Factors: Global Regulators of Plant Development and Response to the Environment. Plant Physiology, 144, 538-549.

http://www.fao.org/ag/agl/agll/spush



Legume carbon metabolism under stress:

Lotus japonicus features

ESTHER M. GONZÁLEZ *, ESTÍBALIZ LARRAINZAR, RUBÉN LADRERA, CRISTINA DE MIGUEL and CESAR ARRESE-IGOR.

Universidad Pública de Navarra, Campus Arrosadia, E-311006, Pamplona, España * Corresponding author click here for Spanish version The effect of drought on nitrogen fixation (NF) has been widely reported (see Zahran, 1999). Among the factors, such as oxygen limitation and nitrogen feedback, a shortage in nodule carbon flux has also been related to the inhibition of NF under drought (Arrese-Igor et al., 1999). In these conditions, nodule sucrose synthase (SS) activity sharply declines (González et al., 1995), thus limiting the carbon flux required for bacteroid respiration. Indeed sucrose accumulation and malate depletion take place in nodules as a result of SS down-regulation (González et al., 1998; Gálvez et al., 2005). Recently, by using a split root system in pea plants, it has been shown that the cause of NF inhibition under drought is of a local origin, rather than relying on a systemic signal (Marino et al., 2007). Key parameters of carbon metabolism showed also a local regulation, correlated to NF inhibition, although nitrogen feedback regulation needs to be further explored in this split root system. Both factors seem to be crucial for the regulation of NF under drought (Ladrera et al, 2007). However, carbon metabolism has been shown to play not such a main but a secondary role in plants of the genus Medicago. Naya et al. (2007) concluded that a decrease in SS expression and activity, although relevant, was not the cause of the drought-induced loss of nitrogenase activity in alfalfa. Interestingly, a similar response has been found in the model legume Medicago truncatula (R. Ladrera, E.M. González, and C. Arrese-Igor, unpublished data). A recent proteome analysis (Larrainzar et al., 2007) of plant and bacteroid fractions of Medicago truncatula root nodules under drought stress reveals that both plant and bacteroid fractions respond simultaneously to water-deficit at the protein level. It can be inferred from the proteomic analysis that the plant response in nodules involves a global reduction of plant protein biosynthesis and a down-shift of cellular carbon and nitrogen metabolism and also sulfur metabolism, thus reducing the energy-demanding process of NF. Drought response of nodule metabolism in Lotus japonicus has not been extensively approached by now. However, several evidences suggest that alkaline invertase could play a relevant role in nodule carbon metabolism (Horst et al., 2007; Flemetakis et al., 2006), diminishing the exclusive role of SS, as carbon supplier of nodule metabolism in the model legume Lotus japonicus. References ARRESE-IGOR C., GONZÁLEZ E.M., GORDON A.J., MINCHIN F.R., GÁLVEZ L., ROYUELA

M., CABRERIZO P.M. and APARICIO-TEJO P.M. 1999. Sucrose synthase and nodule

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Carbon metabolism and water stress 79

nitrogen fixation under drought and other environmental stresses. Symbiosis, 27, 189-212.

FLEMETAKIS E., EFROSE R.C., OTT T., STEDEL C., AIVALAKIS G., UDVARDI M.K. and

KATINAKIS P. 2006. Spatial and temporal organization of sucrose metabolism in Lotus japonicus nitrogen-fixing nodules suggests a role for the elusive alkaline/neutral invertase. Plant Molecular Biology, 62, 53-69.

GÁLVEZ L., GONZÁLEZ E.M. and ARRESE-IGOR C. 2005. Evidence for carbon flux shortage

and strong carbon/nitrogen interactions in pea nodules at early stages of water stress. Journal of Experimental Botany, 56, 2551-2561.

GONZÁLEZ E.M., GORDON A.J., JAMES C.L. and ARRESE-IGOR C. 1995. The role of

sucrose synthase in the response of soybean nodules to drought. Journal of Experimental Botany, 46, 1515-1523.

GONZÁLEZ E.M., APARICIO-TEJO P.M., GORDON A.J., MINCHIN F.R., ROYUELA M. and

ARRESE-IGOR C. 1998. Water-deficit effects on carbon and nitrogen metabolism of pea nodules. Journal of Experimental Botany, 49, 1705-1714.

HORST I., WELHAM T., KELLY S., KANEKO T., SATO S., TABATA S.. PARNISKE M. and

WANG T.L. 2007. TILLING mutants of Lotus japonicus reveal that nitrogen assimilation and fixation can occur in the absence of nodule-enhanced sucrose synthase. Plant Physiology, 144, 806–820.

LADRERA R., MARINO D., LARRAINZAR E., GONZÁLEZ E.M. and ARRESE-IGOR C. 2007.

Reduced carbon availability to bacteroids and elevated ureides in nodules, but not shoots, are involved in the nitrogen fixation response to early drought in soybean. Plant Physiology, (Under review, provisionally accepted)

LARRAINZAR E., WIENKOOP S., WECKWERTH W., LADRERA R., ARRESE-IGOR C. and

GONZALEZ E.M. 2007. Medicago truncatula Root Nodule Proteome Analysis Reveals Differential Plant and Bacteroid Responses to Drought Stress. Plant Physiology, 144, 1495–1507.

MARINO D., FRENDO P., LADRERA R., ZABALZA A., PUPPO A., ARRESE-IGOR C. and

GONZÁLEZ E.M. 2007 Nitrogen fixation control under drought stress: localized or systemic? Plant Physiology, 143, 1968-1974.

NAYA L., LADRERA R., RAMOS J., GONZÁLEZ E.M., ARRESE-IGOR C., MINCHIN F.R. and

BECANA M. 2007. The Response of Carbon Metabolism and Antioxidant Defenses of Alfalfa Nodules to Drought Stress and to the Subsequent Recovery of Plants. Plant Physiology, 144, 1104-1114.

80 E. M. González, E. Larrainzar, R. Ladrera, C. de Miguel and C. Arrese-Igor.

ZAHRAN H.H. 1999. Rhizobium-legume symbiosis and nitrogen fixation under severe conditions and in an arid climate. Microbiology and Molecular Biology Reviews, 63. 968-989.

Acknowledgement Funded by grants DGI-MEC AGL2005-00274/AGR and EC FOOD-CT-2004-506223. E Larrainzar (Formación de Profesorado Universitario), R Ladrera (Formación de Personal Investigador) and C de Miguel (Formación de Personal Investigador) are granted by Ministerio de Educación y Ciencia. Authors thank to Arantza Ederra, Joseba Aldasoro and Gustavo Garijo for technical support.



Legume carbon metabolism under stress:

Lotus japonicus features

ESTHER M. GONZÁLEZ *, ESTÍBALIZ LARRAINZAR, RUBÉN LADRERA, CRISTINA DE MIGUEL and CESAR ARRESE-IGOR.

Universidad Pública de Navarra, Campus Arrosadia, E-311006, Pamplona, España * Corresponding author click here for Spanish version The effect of drought on nitrogen fixation (NF) has been widely reported (see Zahran, 1999). Among the factors, such as oxygen limitation and nitrogen feedback, a shortage in nodule carbon flux has also been related to the inhibition of NF under drought (Arrese-Igor et al., 1999). In these conditions, nodule sucrose synthase (SS) activity sharply declines (González et al., 1995), thus limiting the carbon flux required for bacteroid respiration. Indeed sucrose accumulation and malate depletion take place in nodules as a result of SS down-regulation (González et al., 1998; Gálvez et al., 2005). Recently, by using a split root system in pea plants, it has been shown that the cause of NF inhibition under drought is of a local origin, rather than relying on a systemic signal (Marino et al., 2007). Key parameters of carbon metabolism showed also a local regulation, correlated to NF inhibition, although nitrogen feedback regulation needs to be further explored in this split root system. Both factors seem to be crucial for the regulation of NF under drought (Ladrera et al, 2007). However, carbon metabolism has been shown to play not such a main but a secondary role in plants of the genus Medicago. Naya et al. (2007) concluded that a decrease in SS expression and activity, although relevant, was not the cause of the drought-induced loss of nitrogenase activity in alfalfa. Interestingly, a similar response has been found in the model legume Medicago truncatula (R. Ladrera, E.M. González, and C. Arrese-Igor, unpublished data). A recent proteome analysis (Larrainzar et al., 2007) of plant and bacteroid fractions of Medicago truncatula root nodules under drought stress reveals that both plant and bacteroid fractions respond simultaneously to water-deficit at the protein level. It can be inferred from the proteomic analysis that the plant response in nodules involves a global reduction of plant protein biosynthesis and a down-shift of cellular carbon and nitrogen metabolism and also sulfur metabolism, thus reducing the energy-demanding process of NF. Drought response of nodule metabolism in Lotus japonicus has not been extensively approached by now. However, several evidences suggest that alkaline invertase could play a relevant role in nodule carbon metabolism (Horst et al., 2007; Flemetakis et al., 2006), diminishing the exclusive role of SS, as carbon supplier of nodule metabolism in the model legume Lotus japonicus. References ARRESE-IGOR C., GONZÁLEZ E.M., GORDON A.J., MINCHIN F.R., GÁLVEZ L., ROYUELA

M., CABRERIZO P.M. and APARICIO-TEJO P.M. 1999. Sucrose synthase and nodule

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Carbon metabolism and water stress 79

nitrogen fixation under drought and other environmental stresses. Symbiosis, 27, 189-212.

FLEMETAKIS E., EFROSE R.C., OTT T., STEDEL C., AIVALAKIS G., UDVARDI M.K. and

KATINAKIS P. 2006. Spatial and temporal organization of sucrose metabolism in Lotus japonicus nitrogen-fixing nodules suggests a role for the elusive alkaline/neutral invertase. Plant Molecular Biology, 62, 53-69.

GÁLVEZ L., GONZÁLEZ E.M. and ARRESE-IGOR C. 2005. Evidence for carbon flux shortage

and strong carbon/nitrogen interactions in pea nodules at early stages of water stress. Journal of Experimental Botany, 56, 2551-2561.

GONZÁLEZ E.M., GORDON A.J., JAMES C.L. and ARRESE-IGOR C. 1995. The role of

sucrose synthase in the response of soybean nodules to drought. Journal of Experimental Botany, 46, 1515-1523.

GONZÁLEZ E.M., APARICIO-TEJO P.M., GORDON A.J., MINCHIN F.R., ROYUELA M. and

ARRESE-IGOR C. 1998. Water-deficit effects on carbon and nitrogen metabolism of pea nodules. Journal of Experimental Botany, 49, 1705-1714.

HORST I., WELHAM T., KELLY S., KANEKO T., SATO S., TABATA S.. PARNISKE M. and

WANG T.L. 2007. TILLING mutants of Lotus japonicus reveal that nitrogen assimilation and fixation can occur in the absence of nodule-enhanced sucrose synthase. Plant Physiology, 144, 806–820.

LADRERA R., MARINO D., LARRAINZAR E., GONZÁLEZ E.M. and ARRESE-IGOR C. 2007.

Reduced carbon availability to bacteroids and elevated ureides in nodules, but not shoots, are involved in the nitrogen fixation response to early drought in soybean. Plant Physiology, (Under review, provisionally accepted)

LARRAINZAR E., WIENKOOP S., WECKWERTH W., LADRERA R., ARRESE-IGOR C. and

GONZALEZ E.M. 2007. Medicago truncatula Root Nodule Proteome Analysis Reveals Differential Plant and Bacteroid Responses to Drought Stress. Plant Physiology, 144, 1495–1507.

MARINO D., FRENDO P., LADRERA R., ZABALZA A., PUPPO A., ARRESE-IGOR C. and

GONZÁLEZ E.M. 2007 Nitrogen fixation control under drought stress: localized or systemic? Plant Physiology, 143, 1968-1974.

NAYA L., LADRERA R., RAMOS J., GONZÁLEZ E.M., ARRESE-IGOR C., MINCHIN F.R. and

BECANA M. 2007. The Response of Carbon Metabolism and Antioxidant Defenses of Alfalfa Nodules to Drought Stress and to the Subsequent Recovery of Plants. Plant Physiology, 144, 1104-1114.

80 E. M. González, E. Larrainzar, R. Ladrera, C. de Miguel and C. Arrese-Igor.

ZAHRAN H.H. 1999. Rhizobium-legume symbiosis and nitrogen fixation under severe conditions and in an arid climate. Microbiology and Molecular Biology Reviews, 63. 968-989.

Acknowledgement Funded by grants DGI-MEC AGL2005-00274/AGR and EC FOOD-CT-2004-506223. E Larrainzar (Formación de Profesorado Universitario), R Ladrera (Formación de Personal Investigador) and C de Miguel (Formación de Personal Investigador) are granted by Ministerio de Educación y Ciencia. Authors thank to Arantza Ederra, Joseba Aldasoro and Gustavo Garijo for technical support.



Condensed tannins in Lotus species under salt stress

FRANCISCO ESCARAY1, JULIETA PESQUEIRA1, FRANCESCO DAMIANI2, FRANCESCO PAOLOCCI2, PEDRO CARRASCO SORLI3 and OSCAR A. RUIZ1 1IIB-INTECh; UNSAM-CONICET CC 164 (7130) Chascomús, Argentine. 2Instituto di Genética Vegetale – Perugia, Consiglio Nazionale delle Ricerche (CNR), Via Madonna Alta n. 130, 06128 Perugia, Italy 3Director del Departament de Bioquímica i Biología Molecular. Universitat de València (Spain). * Corresponding author click here for Spanish version Condensed Tannins (CTs) are polymeric flavanols formed by condensation of monomeric units such as flavan-3-ols and flavan-3-4-diols (Foo et al., 1996). In Lotus species used as forages, a CT content in the range of 1 to 5 mg/g DM is beneficial, in that it prevents cattle bloating and intestinal invasion by parasites (Niezen et al., 1995; Li et al., 1996; Waghorn and Shelton, 1997; Otero and Hidalgo, 2004). In addition, CTs have been proposed to play a role in the interactions between plants and microorganisms, either pathogenic or mutualistic, as well as in plant responses to abiotic stresses (Panckurst and Jones, 1979; Barry and Manley, 1986; Dixon and Paiva, 1995; Gebrehiwot et al., 2002; Reinoso et al., 2004; Paolocci et al., 2005). Lotus species exhibit significant variations in shoot and root CT content, both between and within populations (Sivakumaran et al., 2006). Within this genus, the forage species L. tenuis (=L. glaber Mill.) is particularly important, due to its good adaptation to saline-alkaline soils of the Salado River Basin (Buenos Aires Province, Argentina). One of the aims of our work is to determine the relations between TC metabolism and plant responses to soil salinity. In relation with this topic, experiments were performed using different Lotus species, some of them used as forage crops (L. tenuis and L. corniculatus), some others considered as models for studies on molecular biology and genetics (L. burttii, L. filicaulis, L. japonicus ecotypes Gifu and MG-20) and other species such as L. creticus. These species and ecotypes were exposed to salinity, by employing a progressive salinization protocol that reached a final NaCl concentration of 150 mM. Plants irrigated with a nutrient solution without NaCl were used as controls. Twelve replicates (plants) from each species/ecotype were harvested and TC content was determined in shoots, leaves and roots. Significant and contrasting modifications were detected in foliar TC content of L. creticus and L. corniculatus. L. japonicus ecotypes Gifu and MG-20 differed in their foliar TC content, although the levels of these metabolites were not affected by salinity in these ecotypes. Interestingly, differences in shoot anthocyanin contents of these two L. japonicus ecotypes were also detected. Salinity induced and increase in shoot TC content of L. burttii and both L. japonicus ecotypes, which ranged between 21 and 28 %, as compared with controls irrigated without NaCl. Regarding L. filicaulis, salinity increased shoot TC content by 87%. Root TC content diminished in a variable degree in L. burttii, L. japonicus

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82 F. Escaraay, J. Pesqueira, F. Damiani, F. Paolocci, P. Carrasco Sorli and O.A. Ruiz

and L. tenuis plants exposed to salinity, while this parameter increased by 27% in L. filicaulis plants. References BARRY T.N. and MANLEY T.R. 1986. Interrelationships between the concentrations of total

condensed tannin, free condensed tannin and lignin in Lotus sp. and their possible consecuences in ruminant nutrition. Journal of the Science of Food and Agriculture, 37, 248-254.

DIXON R.A. and PAIVA N.L. 1995. Stress-induced phenylpropanoid metabolism. The Plant Cell, 7, 1085-1097.

FOO L.Y., NEWMAN R., WAGHORN G., MCNABB W.C. and ULYATT M.J. 1996.

Proanthocyanidins from Lotus corniculatus. Phytochemistry, 41, 617-624. GEBREHIWOT L., BEUSELINCK P.R. and ROBERTS C.A. 2002. Seasonal variations in

condensed tannin concentration of three Lotus species. Agronomy Journal, 94, 1059-1065.

LI YU-GUANG, TANNER G. and LARKIN P. 1996. The DMACA-HCl protocol and the

threshold proanthocyanidin content for bloat safety in forage legumes. Journal of the Science of Food and Agriculture, 70, 89-101.

NIEZEN J.H., WAGHORN T.S., WAGHORN C.G. and CHARLESTON W.A.G. 1995. Growth

and gastrointestinal nematode parasitism in lambs grazing either Lucerne (medicago sativa) or sulla (Hedysarum coronarium) which contains condensed tannins Journal of agricultural cience, 125 (2), 281-289.

OTERO M.J. and HIDALGO L.G. 2004. Taninos condensados en especies forrajeras de clima

templado: efectos sobre la productividad de rumiantes afectados por parasitosis gastrointestinales (una revisión) Livestock Research for Rural Development, 16 (2). Art. #13.

PANCKURST C.E. and JONES W.T. 1979. Effectiveness of Lotus root nodules. Journal of

Experimental Botany, 30, 1095-1107. PAOLOCCI F., BOVONE T., TOSTI N., ARCIONI S. and DAMIANI F. 2005. Light and an

exogenous transcription factor qualitatively and quantitatively affect the biosynthetic pathway of condensed tannins in Lotus corniculatus leaves. Journal of Experimental Botany, 56, 1093-1103.

REINOSO H., SOSA L., RAMÍREZ L. and LUNA V. 2004. Salt-induced changes in the

vegetative anatomy of Prosopis strombulifera (Leguminosae). Canadian Journal of Botany 82 (5), 618-628.

Tannins in saline stress 83

SIVAKUMARAN S., RUMBALL W., LANE G.A., FRASER K., FOO L.Y., YU M. and MEAGHER P. 2006. Variation of Proanthocyanidins in Lotus Species. Journal of Chemical Ecology, 32, 1797-1816.

WAGHORN C.G. and SHELTON I.D. 1997. Effect of condensed tannins in Lotus corniculatus

on the nutritive value of pasture for sheep. Journal of Agricultural Science, 128, 365-372.

Lotus Newsletter (2007) Volume 37 (2), 84-85.


Genetic manipulation of condensed tannin biosynthesis in Lotus

spp.

FRANCESCO PAOLOCCI*, SERGIO ARCIONI and FRANCESCO DAMIANI

National Research Council, Plant Genetics Institute- Perugia, Via Madonna Alta, 130 06128 Perugia, Italy * Corresponding author Condensed tannins (CTs), also known as proanthocyanidins (PAs), are plant secondary metabolites that share most of their biosynthetic pathway with anthocyanins. CTs are polymeric flavonoids composed primarly of epicatechin and/or catechin units. They act as antioxidants with beneficial effects on human and animal health. In planta, CTs act as protective agents against pathogens, pests and diseases and control seed permeability and dormancy. These compounds strongly affect plant quality traits: the palatability and nutritive value of forage legumes are highly influenced by their concentration and structure. High concentrations of CTs can decrease the palatability and digestibility of plants. Conversely, moderate quantities of CTs (2-4% dry matter) in forage prevent proteolysis during ensiling and rumen fermentation, thereby protecting ruminants against pasture bloat (Tanner, 2004). Unfortunately, CTs are not accumulated in leaves of the most valuable forage species such as alfalfa and clovers. The genus Lotus offers a wide range of options for studying the regulation of CTs as it includes species which accumulate CTs only in flowers and stems (L. japonicus, L. tenuis) or in flower, stems and leaves (L. corniculatus). Equally interesting is that, as opposed to Arabidopsis that has yielded critical information regarding the transcriptional control of genes involved in CT biosynthesis in seed coats, in L. corniculatus and L. japonicus CT polymers are synthesised from both epicatechin and catechin starter units and not only from epicatechin. We aimed to understand the genetic and environmental determinants controlling leaf CT accumulation in L. corniculatus. To this purpose, either partial or full length cDNAs from the structural genes of the CT pathways (PAL, CHS, DFR, ANS, ANR, LAR1 and LAR2) were cloned. Their expression patterns were studied under different growth conditions and in different genetic backgrounds resulting from the transformation of wild type genotypes, polymorphic for the levels of leaf CTs, with exogenous regulators of anthocyanins belonging either to the bHLH or MYB gene families. More specifically, here we show that in L. corniculatus it is possible to specifically up- and down-regulate leaf CT biosynthesis using heterologous activator/repressor genes, without inducing significant alteration on levels of other flavonoid end products. We also show that the epicatechin (via ANR) and catechin (via LAR) branches of the CT pathways are subjected to a coordinate transcriptional regulation (Paolocci et al., 2007). Strategies to switch on the CT pathway in legume species that don’t synthesize these polymers in leaves are also discussed.


Título abreviado del resúmen 85

References TANNER G.J. 2004. Condensed Tannins. In Davies K.M. (Ed). Plant pigments and their

manipulation. Annual plant reviews Vol 12. Blackwell Publishing-CRC press, Boca Raton, FL, USA pp 150-184.

PAOLOCCI F., ROBBINS M.P., MADEO L., ARCIONI S., MARTENS S. and DAMIANI F. 2007.

Ectopic expression of a bHLH gene transactivates parallel pathways of proanthocyanidin (PA) biosynthesis. Structure, expression analysis and genetic control of LAR and ANR genes in Lotus corniculatus. Plant Physiology, 143, 504-516.



Genetic diversity in the rhizobia isolated from endemic Lotus to

the Canary Islands

MILAGROS LEÓN BARRIOS * and JAVIER DONATE CORREA.

Departamento de Microbiología y Biología celular. Universidad de La Laguna. 38071 La Laguna. Tenerife. Islas Canarias. España.

* Corresponding author click here for Spanish version The genus Lotus includes numerous endemic species in the Canary Islands. They usually show an island distribution pattern, which is exclusive of single Island and has a reduced area, being many of them threatened or in danger of extinction. The rhizobia were obtained from root nodules of plants collected from their native locations. When this was not possible due to the reduced number of specimens, germinated seeds or cuttings were used as tramp-plant on soils where the wild populations were growing. In this study the rhizobia were isolated from L. callis-viridis, L. kunkelii and L. arinagensis in Gran Canaria Island, from L. berthelotii, L. sessilifolius and L campylocladus in Tenerife, from L. pyranthus in La Palma and from L. lancerottensis in Lanzarote. The isolates were characterized through their restriction patterns and sequencing of the 16S ribosomal DNA and the symbiotic gene nodC. The results showed a great diversity among the rhizobia nodulating the different Lotus species in the Canary Islands, finding that they belong to different species from the genera Mesorhizobium, Sinorhizobium and Rhizobium. The genus Mesorhizobium was more frequently isolated, appearing in all the Lotus species tested. This rhizobia genus was represented by genotypes that belong to several different species, many of which may constitute new species for this genus. In general, the genotypes detected did not correlate with a particular Lotus species nor with a single Island, although some seem to correlate with a particular environment. Thus, one genotype dominated in the halopsamophile environments. Symbiotic genes do not correlate with the rhizobial classification and intrageneric horizontal gene transfer seems to be a usual phenomenon in these natural environments.

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Use of Lotus/Rhizobium Symbiosis in Regeneration of Polluted

Soils ISABEL VIDEIRA E CASTRO*1, PAULA SÁ-PEREIRA2, FERNANDA SIMÕES2, JOSÉ A. MATOS2 and EUGÉNIO FERREIRA1 1Dep. Ecologia, Recursos Naturais e Ambiente, Laboratório de Microbiologia, INRB, Av. da República, Nova Oeiras, 2780-159 Oeiras, Portugal 2Dep. Biotecnologia, Grupo de Biologia Molecular, INETI, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa, Portugal * Corresponding author click here for Portuguese version In polluted soils the presence of toxic inorganic compounds such as heavy metals has an important impact on the resident microflora, which seems to be much less varied in polluted areas. In last years, our group has been involved in projects aimed to evaluate the harmful effects of long term heavy metals contamination of soils on the Rhizobium-legume symbiosis, mainly those ones with R. leguminosarum bv. trifolii and Trifolium sp. (Castro et al., 1997; 2003). An important activity for regeneration soils polluted by industrial activities is the establishment of vegetation. Leguminous plants can have, here, an important role due their interesting agricultural potential, their capacity to fix atmospheric nitrogen and adaptation to low input agricultural systems. Particularly in the case of Lotus species, some of them are present in rather extreme conditions such as those existing in contaminated soils. The aim of this work was to examine the effects of soil pollution on the genetic and phenotypic characteristics of rhizobial population isolated from Lotus sp. growing in contaminated soils (mainly with Hg and As). The soils were selected from an industrial area with known environmental pollution problems, where heavy metals and other pollutants have been emitted for nearly 40 years. This area is particularly affected by the release of liquid effluents from fertilizer and chemical industries. Taking in account that symbiotic interactions between species of the genus Lotus and Rhizobium strains can be effective, ineffective or parasitic according with to combination, nodulation tests were evaluated with different lotus species. Several parameters were also analysed such as population size, nitrogen fixation capacity, genetic diversity and mercury and arsenic tolerance. The results suggested that some of the Lotus/Rhizobium symbioses seem to be particularly well adapted to adverse environmental conditions and can be an adequate tool for bioremediation of polluted soils. References CASTRO I.V., FERREIRA E.M. and MCGRATH S.P. 1997. Effectiveness and genetic diversity

of Rhizobium leguminosarum bv. trifolii isolates in portuguese soils polluted by industrial effluents. Soil Biology & Biochemistry, 29, 1209-1213.

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88 I. Videira E Castro, P. Sá-Pereira, F. Simões, J.A. Matos and E. Ferreira

CASTRO I.V., FERREIRA E.M. and MCGRATH S.P. 2003. Survival and plasmid stability of rhizobia introduced into a contaminated soil. Soil Biology and Biochemistry, 35, 49-54.

This work was supported by FCT, POCTI (AGG/4607/2002) and FEDER



Legumes as model plants to study nutrient transport processes in

arbuscular mycorrhiza NURIA FERROL*

Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Profesor Albareda 1, 18008 Granada, Spain * Corresponding author click here for Spanish version Many microorganisms form symbioses with plants that range, on a continuous scale, from parasitic to mutualistic. Among these, the most widespread mutualistic symbiosis is the arbuscular mycorrhiza (AM), formed between some soil-borne fungi (AM fungi) belonging to the phylum of the Glomeromycota and most vascular flowering plants. These associations occur in terrestrial ecosystems throughout the world and have a global impact on plant mineral nutrition and health, as well as on the structure of plant communities. The main physiological basis for mutualism in the AM symbiosis is bi-directional nutrient transfer. The plant supplies the fungus with carbon (from its fixed photosynthates) while the fungus assists the plant on its uptake of mineral nutrients from the soil. During the root colonization process, the AM hyphal branches penetrate the cortical cell wall and differentiate within these cells to form highly branched structures, known as arbuscules. These fungal structures, which establish a large surface of contact with the plant protoplast, play a key role in reciprocal nutrient exchange between the plant cells and the AM fungal symbiont. Simultaneously to intraradical colonization, the fungus develops an extensive network of hyphae in the soil surrounding the root. This extraradical mycelium explores and exploits soil microhabitats for nutrient acquisition and its function is critical for the absorption low mobility nutrients, mainly phosphorus, ammonium, and some micronutrients such as copper and zinc. AM fungi, as obligate symbionts, rely on the plant host for the supply of carbon assimilates required for their growth, maintenance and function. Development of this highly compatible association requires the coordinate molecular and cellular differentiation of both symbionts to form specialized interfaces over which bi-directional nutrient transfer occurs. Despite the agronomic and ecological importance of the AM symbiosis, the molecular and cellular events associated with the establishment and functioning of the association are poorly understood. Progress in understanding the genetic and molecular basis of this important symbiotic association has been hampered by the obligate biotrophy of the fungal partner, the difficulties to isolate the intraradical fungal structures and by the lack of mycorrhiza formation on the plant model species Arabidopsis thaliana. In recent decades, the use of legume plants, such as Medicago truncatula and Lotus japonicus, as experimental systems for research of the AM symbiosis, as well as the application of powerful molecular techniques to study the genome of AM fungi has increased our understanding of the molecular mechanisms underlying bi-directional nutrient transport processes in a mycorrhizal plant. Current knowledge on the mechanisms of phosphate and nitrogen uptake

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90 N. Ferrol

and transport by AM fungi as well as on carbon transfer from the plant to the fungus will be presented.

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