chemical ecology and biodiversity · chemical ecology and biodiversity martine hossaert-mckey...
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Chemical Ecology and Biodiversity
Martine HOSSAERT-McKEYCentre
Fonctionnelle et Evolutive-CNRS, Montpellier, France
Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010
Chemical mediation and the dynamicsof biodiversity
At the heart of fundamental questions in
evolutionary biology and functional ecology
The functioning of ecosystems
The origin and maintenance of biodiversity
Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010
Practical applications: « ecological
chemistry », « green chemistry »
Incredible diversity of natural substances
potentially useful to humans
How to inventory them ?
Going beyond inventory
Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010
How to inventory them ?
- Random (screening)
- Use chemotaxonomy as a guide
“Ecology-driven”: use the exceptional metabolic creativity that organisms employ in mediating their biotic interactions
“Ethnobiology-driven”: use folk knowledge as a guide
Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010
“Natural substances" : Products of natural selection
The principle of biomimicry : Natural selection has had
millions of years to invent solutions to problems.
“Imitating nature” is often the most efficient means to
resolve some problems.
Sharkskin and the high performance of a new
kind of swimsuit
Moth cocoons and a next-generation glue
Natural substances are also at the foundation of biotic
interactions
GDR Ecologie Chimique – created in 2003
15 laboratories
Exchanges and collaborative research
Shared tools: Plate-formes for chemical analysis, MS
libraries, GC-EAD, ….
A website: www.gdrec.univ-rennes1.fr
Annual meetings
‘Eco-chimiothèque’ (see poster at this meeting)
Organization of this meeting!
Chemical mediation in mutualistic interactions
Chemical mediation in insect societies
Functional ecology of chemical mediation
Sensory ecology of chemical mediation
Chemical communication in vertebrates
GDR Ecologie Chimique: principal researchthemes
Collaborations with the Chinese
Academy of Science :
Xishuangbanna Tropical Botanical Garden Yunnan
Kunming Institute of Botany, Yunnan
Pollen transport
Breeding site
Obligatory & specific
Insect Plant
Fig/fig wasp mutualism: a model system in evolutionary
biology
Roughly this coevolved mutualism
NURSERY POLLINATION MUTUALISMSThe pollinators reproduce in the flowers they pollinate
The fig / fig wasp mutualism
Development of wasps and seeds
Female pollinators
Receptive fig
Male-phase fig
A new generation of pollinating wasps
Pollination and oviposition
Signal facilitating the encounter of the two mutualists
- Mutualism : the two partners benefit from the encounter
- Species-specific interactions :
A strong signal
A specific signal
Collection of volatile compounds by headspace
Figs enclosed in a bag
made of inert plastic
Filter retaining the
molecules of volatile
compounds
(adsorption)
Charcoal filter to purify
the entering air
Ficus semicordata at XTBG4-methylanisole = 90% of the floral scent of figs atreceptivity
(Chen Chun et al. Functional Ecology 2009)
Species-specific mutualisms: both partners have an interest in efficient signal transmission and reception
Selection favours a strong and SIMPLE signal
SIMPLE signal: unambiguous signal in complex
environments
« Private channels » (Soler et al. 2010)
Biosynthesis of rose scent compounds
Sylvie Baudino-CaissardLaboratoire Bvpam
Université de Saint-Etienne
Laboratoire Reproduction et Développement des Plantes
ENS Lyon
Laboratoire GenhortINRA Angers
W.-B. Sun Botanical Institut
Kumning
Introduction
2 very different fragrances in different rose species
Typical rose scent
Rosa gallicaRosa gigantea
PE
G
Ci
H3CO OCH3
Geraniol and derivatives2-Phenylethanol
3,5 Dimethoxytoluene
DMT
« Tea scent »
Benzenoids/
Phenylpropanoids
Monoterpenealcohols
DMT
GDIo
Diversity of scent and phylogeny
ChinenseSynstylaeCaninae
Genus Rosa : 150 species, 10 sections
Gallicanae
Banksiae
Bracreatae
Caninae
CaninaeGallicanae
LaevigataeSynstylae
SynstylaeSynstylae
PimpinellifoliaePimpinellifoliae
Cinnamomeae
CinnamomeaeCinnamomeae
SynstylaeCinnamomeae
Carolinae
Tea scent
Roses from the Chinense section
OH
2-phenylethanol
Roses from other sections : Synstylae, Cinnamomeae, Pimpinellifoliae, Caninae, Gallicanae, Carolinae
Question n°1
Why don’t they make DMT ?
3HCO
CH3
3,5-dimethoxytoluene
HO OCH3
CH3
orcinolHO OH
CH3
MHT DMT
OOMT1 OOMT2OCH31 2
Chinese section
R. chinensiscvOld Blush
R. gigantea R. chinensis spontanea
R. xodorata R. xodorataochroleuca
Tyr Phe
ߟ Roses from the Chinense section have both OOMT1 and OOMT2 genes
ߟ Roses from other sections only have OOMT2 genes
Sca
lliet
et a
l., P
NA
S 2
008
OOMT1 & OOMT2
Phe
Tyr Phe
ancestral OOMT2 gene
OOMT2
OOMT1 - OOMT2
3HCO
CH3
3,5-dimethoxytoluene
HO OCH3
CH3
orcinolHO OH
CH3
MHT DMT
OOMT1 OOMT2
OCH3
Petal specificOOMT2 gene
Hypothesis on OOMTs evolution
An association between soil fungi and roots of >85% of plants
Reciprocal nutrient exchanges + protection:
PLANT FUNGUS
Sugars, B vitamins
Water and N, P, K
Protection against soil pathogens and abiotic stress
MYCORHIZAL SYMBIOSIS
MYCOHETEROTROPHY
400 forest species in 87 genera (Leake 1994)
Achlorophyllous, without stomata: heterotrophic
Not direct parasites on other plants : a fungus is providing food to the roots: mycoheterotrophy (MH)
Sarcodessanguinea
Gymnosiphon minutus
MYCOHETEROTROPHY
Mycorrhizal association
GREENTREE
MYCOHETERO-TROPHIC PLANT
FUNGUSMycorrhizal association
Carbon flow
Cf. 14C labelling (McKendrick et al., 2000and 13C abundance (Trudell et al., 2003)
Under (or at) compensation point, for various reasons
Partial heterotrophy, by using fungal carbon (0-80%):
Curious green orchids ?
Mixotrophic plant, performing photosynthesis andcarbon compounds from its fungal symbiont(s)
Carbon flow
Mycorrhizal association
GREENPLANT
MIXOTROPHIC, GREEN PLANT
FUNGUSMycorrhizal association
Photosyntheticcarbon
The ubiquity of chemical mediation
Chemical mediation plays key roles in these
interspecific interactions
These interactions are the structural « glue » that
binds ecological communities and determines their
functioning
Biodiversity and natural resources management3rd Sino-French seminar – October 5th to 8th , 2010