the mul(-func(onal brassinosteroid biosmulant , vitazyme, …€¦ · growth, soil health and...

TheMul(-Func(onalBrassinosteroidBios(mulant,Vitazyme,ImprovesPlantGrowth,SoilHealthandTolerancetoGlyphosateHerbicideStress

RobertJ.Kremera,bManjulaV.Nathana,b,PaulW.Syl(ec,TimReinboIb,KellyNelsonb,andXiaoweiPanbaUniversityofMissouri,SchoolofNaturalResourcesandbDivisionofPlantSciences,Columbia,Missouri,USA

cVitalEarthResources,Gladewater,Texas,USA

Introduc(on

Results

Figure2.Soilhealthbiologicalindicatorsformaizeproduc(onwithglyphosateherbicideandVitazymebios(mulant

a

9.56 9.31

19.9

8.75

1614.3

19.7

14

0

5

10

15

20

25

Control Vitazyme Glyphosate Vita+Gly

Fusariu

mco

lonies/100cmro

ot

2014

2016

13.4 13.5

11

20

7.9759.4

6

8.6

0

5

10

15

20


RootDryM

assg

/plant 2014

2016

2521.8

6.5

41

62.6

76.6

29.4

64.5

0

10

20

30

40

50

60

70

80


IAA-prod

ucingBa

cteriacfu/gX10

4

2014

2016

132

158

103

175

0

30

60

90

120

150

180


SoilglucosidaseugPNP/gdrysoil

2016

Figure1.Soilhealthbiologicalindicatorsforsoybeanproduc(onwithglyphosateherbicideandVitazymebios(mulant

0

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Control VitazymeGlyphosate Vita+Gly

PLFA

nmole/gdrysoil

Pro(st

AMF

Fungi

Ac(no

Gpos

Gneg

2016139

154

115

144

SoybeanrhizospheresoilmicrobialdiversityexpressedassoilmicrobialPLFAcomponents.Barvalues=TotalPLFA(microbialbiomass)

0

20

40

60

80

100

120

140

PLFA

nmole/gdrysoil

Pro(st

AMF

Fungi

Ac(no

Gpos

Gneg

2016176166

136

168

Maizerhizospheresoilmicrobialdiversity.Barvalues=TotalPLFA(microbialbiomass)

36.6

43

11.3

4139.3

41.5

19.4

47.5

0

10

20

30

40

50


Rhizosph

erePseu

domon

adsC

FU/g 2014

2016

IAAbacteriadetectedviapinkcolorreac(onwithSalkowskireagentonmembranetemplate

Vitazyme Glyphosateonly

FluorescentpseudomonadsdetectedviaUVlight

Soybeanrootcoloniza(onbyFusariumspp.

Vitazyme+Glyphosate Glyphosate

Mn-transformingbacteriaonselec(vemedium;Mnoxidizersappearblack;Mnreducersform

halos

Glyphosateonly Vitazyme0

5

10

15

20

25

30


MnReducers

MnOxidizers

MnTran

sformingBa

cteriacfuX103/gso

il

1.57 2.17

0.38

1.772016

Barvalues=Mnred/Mnoxra(o

51.0

63.3

43.3

56.1

71

90

55

83

0

10

20

30

40

50

60

70

80

90


MaizeRoo

tDryM

assg

/plant

2016

2017

17.817

21.3

15.8

9.5 10.15

16.5

10.25

0

5

10

15

20

25


Fusariu

mcolon

ies/100cm

root

2016

2017

51.455.5

30.5

66.3

10.5

18.6

2.5

16.25

0

10

20

30

40

50

60

70


Rhizosph

erepseu

domon

adsc

fu/g

X104

20162017

29.1

35

20.8

41.4

7.125

11.62

2

10.75

0

5

10

15

20

25

30

35

40

45


IAA-prod

ucingBa

cteriacfu/gX10

4

2016

2017

0

2

4

6

8

10

12

14

16

18

20


Mn-tran

sformBacteria

cfu/gX1

04

MnReducers

MnOxidizers2016

1.42.1

0.6

1.6

Figure3.Poten(aleffectofVitazymeonrela(onshipofsoilresidualglyphosateandsoybeangrainyield(2014&2016).Individualplotdata)

Maizerootcoloniza(onbyFusariumspp.

GlyphosateVitazyme+Glyphosate

A

B

C

D

E

F G

Soybeanrhizospheresoilmicrobialac(vityindicatedbysoilglucosidase,aC-cyclingenzyme.

A

B

C D

E F

SoybeanrootbiomassenhancedbyVitazyme

Pseudomonadbacteriainmaizerhizosphere IAAbacteriainmaizerhizosphere

Mn-transformingbacteriainmaizerhizospherewithred/oxra(os

Bios3mulantsenhancenutrientuptakeandcropquality,however,knowledgeofeffectsonsoilhealthislimited(Kremer2017a).Thebios3mulantVitazymeprovides several modes of ac3on mediated by mul3ple ac3vebrassinosteroids. AKributes of brassinosteroid-based bios3mulants includeenhanced root development, improved nutrient uptake efficiency, diseasesuppression, and environmental stress tolerance (Hayat & Ahmad 2011).Limited research has shown that brassinosteroids may regulate pes3cidemetabolisminplants(Zhouetal.2015),however,noinforma3onisavailableonpoten3alforovercomingstressoftheherbicideglyphosateonrhizospherebiology in transgenic (gene3cally-modified, [GM]) cropping systems.Glyphosate affects rhizosphere microbial diversity and ac3vity, increasedfungal root coloniza3on, decreased beneficial bacterial components, anddetrimentaleffectsoncroprootgrowth(Kremer&Means2009;Wagneretal.2003).VitazymewasappliedinsoybeanandmaizefieldtrialsinMissouriUSAduring2014-2017,withandwithoutglyphosateapplica3on.

•  DetermineeffectsofVitazymeonselectedsoilhealthindicators•  DetermineeffectsofVitazymeonrhizospherebiologyin

transgenicsoybeanandmaizereceivingglyphosateinfieldtrials•  Determinepoten3aleffectsofVitazymeoncropgrowthinsoils

withresidualglyphosatecontents

Vitazyme-improvedsoilhealthindicatorandovercameglyphosateeffectsonmaizeandsoybeanatallsitesacrossyears:•  Rootgrowth(drybiomass)improved(Figs.1A&2A)whilecoloniza3onbypoten3allypathogenicFusariumfungiwassignificantly(p<0.05)reduced(Figs.1B&2B),rootnodula3ononsoybeanimprovedordidnotdecreasewithglyphosate+Vitazyme(datanotshown)

•  Rhizospherefluorescentpseudomonads,themajoritycontributebeneficialplantgrowth-promo3ngfunc3ons,andIAA-producingbacteria,significantlyincreasedinbothglyphosate-treatedcrops(Figs.1C&2CandFigs.1D&2D,respec3vely)

•  MaintainedhighMnreducerstoMnoxidizersra3o,notablyinpresenceofglyphosate,sugges3ngadequateavailableMn(reduced)forplantandmicrobialuptakeandmetabolism,andlimi3ngunavailable,immobilizedMn(oxidized)associatedwithglyphosateandoxidizingbacteria(Figs.1Eand2E)

•  Maintainedsoilmicrobialcommunitycomposi3on(PLFAgroups)andtotalmicrobialbiomassinglyphosatetreatedcropsatsimilarlevelsofcontrol,non-glyphosatesoils,whichtendedtoimprovemycorrhizalcomponent(Figs.1F&2F)

•  Enhancedglucosidaseac3vity,indicatorofsoilmicrobialfunc3on,inbothcontrolandglyphosatetreatments(Fig.1G)

GlyphosateSoilResiduesandGrainYields:•  Residualglyphosatecontentsinsoilrangedfrom0to>1000μg/

kg(ppb)ofsoil,whichwasrandomlydistributedamongplotsatfieldsites,regardlessofglyphosateapplica3on3ming

•  Soybeangrainyieldsincreased1to4%withVitazymewhilemaizeyieldsincreased1to4%(datanotshown)

•  Norela3onshipbetweenyieldsofindividualplotswithsoilglyphosatecontentwasfoundformaize(2016)

•  Apparentrela3onshipbetweensoybeanyieldinindividualplotswithsoilglyphosate-tendencyforloweryieldwithhighersoilglyphosate;Vitazymemayoffsetpoten3alyielddeclineduetoglyphosatebuildupinaMexicosiltloam(6of8plots;Fig.3)

S065

Experimental• FieldtrialsconductedatColumbia(2014)andNovelty(2016-17)MissourionMexicosilsoil(fine,smec33c,mesicVer3cEpiaqualfs),maizeandsoybeanplantedconven3onallyusingminimum3llage;plantsandsoilscollectedatR2soybean&V10maizegrowthstage• Root-colonizingFusariumassessedbyselec3veculturetechnique(Levesqueetal.1993)• RhizospherepseudomonadsdeterminedusingS1agarmedium(Gouldetal.1985)•  Indoleace3cacid-producing(IAA)bacteriadetectedonnitrocellulosemembranesreactedwithSalkowskireagentforcolordevelopment(Bricetal.1991)• Mn-transformingbacteriadetectedonGerretsen’smedium(Huber&Graham1992)• Glucosidaseac3vitydetectedusingenzymeassayofEivazi&Tabatabai(1988)• SoilmicrobialcomponentsandbiomassdeterminedusingphospholipidfaKyacid(PLFA)analysis(Buyer&Sasser2012;PritcheKetal.2011)

Conclusions•  Apolyphasicmicrobialanalysisentailingmul3pleassessments

ofsensi3vesoilhealthindicators,previouslyusedtoevaluateGMcropeffectsonsoilbiologyandecology(Kremer&Means2009),wassuccessfullyadaptedforevalua3ngthebios3mulantVitazymeasameansofsuppressingeffectsofglyphosateonrootgrowthandrhizospherebiologyin(GM)croppingsystemsandmaintainingorimprovingsoilhealth.

•  SoilmicrobialdiversitybasedonPLFAanalyseswasrestoredbyVitazymeinsoilsplantedtomaizeandsoybeantreatedwithglyphosate;ahighmicrobialdiversityisessen3altomaintainastableecosystemandcropproduc3vity(Graystonetal.1998).

Conclusionscon(nued:•  GlyphosateresiduebuildupinsoilsunderGMcropsisareality

(Kremer2017b)andmayaffectcropgrowthandyieldsinfutureseasons.Bios3mulantssuchasVitazymemightoffseteffectsofresidualglyphosate(Fig.3),howevermoreevalua5onunderrigorousexperimentalcondi5onsisrequiredtoconfirmeffects.

•  Resultsfromthisprojectdemonstratethatbios3mulantscanbeamajormanagementfactorforaddressingrecurrentproduc3vityproblemsanddecliningsoilhealthassociatedwithGMcropsincurrentcropproduc3onsystems

Note:Referencescitedhereinareavailableashardcopyhandoutsorasapdfuponrequest.

Objec(ves

y=-5.6766x+4544.4R²=0.31405

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SoybeanGrainYield(k

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SoilResidualGlyphosate(μg/kgsoil)

uGlyphosateonlyuGlyphosate+Vitazyme

the mul(-func(onal brassinosteroid biosmulant , vitazyme, …€¦ · growth, soil health and...

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