the mul(-func(onal brassinosteroid biosmulant , vitazyme, …€¦ · growth, soil health and...
TRANSCRIPT
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
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10
15
20
Control Vitazyme Glyphosate Vita+Gly
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
Control Vitazyme Glyphosate Vita+Gly
IAA-prod
ucingBa
cteriacfu/gX10
4
2014
2016
132
158
103
175
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30
60
90
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Control Vitazyme Glyphosate Vita+Gly
SoilglucosidaseugPNP/gdrysoil
2016
Figure1.Soilhealthbiologicalindicatorsforsoybeanproduc(onwithglyphosateherbicideandVitazymebios(mulant
0
20
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120
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
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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
Control Vitazyme Glyphosate Vita+Gly
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
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15
20
25
30
Control Vitazyme Glyphosate Vita+Gly
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
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20
30
40
50
60
70
80
90
Control Vitazyme Glyphosate Vita+Gly
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
Control Vitazyme Glyphosate Vita+Gly
Fusariu
mcolon
ies/100cm
root
2016
2017
51.455.5
30.5
66.3
10.5
18.6
2.5
16.25
0
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20
30
40
50
60
70
Control Vitazyme Glyphosate Vita+Gly
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
Control Vitazyme Glyphosate Vita+Gly
IAA-prod
ucingBa
cteriacfu/gX10
4
2016
2017
0
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6
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Control Vitazyme Glyphosate Vita+Gly
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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