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Overview on glyphosate resistant weed mechanisms

Overview on glyphosate resistant weed mechanisms

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D Sammons D Sammons Presentation Transcript

  • Overview on glyphosate resistant weed mechanisms Dr. Doug Sammons 23/3/2010 Monsanto Company
  • Glyphosate Global Resistance (17) Weedscience.org, 2/25/2010 * Target site mutant, † Exclusion Plantago C3-(2003), Buckhorn plantain (S. Africa) Parthenium * C3/C4-(2004), Ragweed parthenium (Columbia ) Examples of 1-3X Eleucine * C4-(1997), Goosegrass (Malaysia, Columbia,Taiwan) magnitude Echinochloa C4-(2007), Barnyard grass (Australia) resistance Euphorbia C4-(2006), Wild Poinsettia (Brasil) Kochia C4-(2007), Tumbleweed (KS) Lolium * C3-(2001), Italian Ryegrass (S. America, France , Italy, Spain, 6 States) Lolium * † C3-(1996), Rigid Ryegrass (Aus.,4 prov., CA, S. Africa, France, Italy,Spain) Amaranthus C4-(2005), Waterhemp (5 States) Amaranthus* † C4-(2005), Palmer pigweed (10 States) Sorghum † C4-(2005), Johnsongrass (Argentina, MS, AR) Digitaria C4-(2008), Sourgrass (Brazil, Paraguay) Examples of 6-8X Ambrosia † C3-(2004), Giant ragweed (6 States) magnitude Ambrosia C3-(2004), Common ragweed (6 States) resistance Conyza † C3-(2000), Horseweed (17 states, Brasil, China, Spain) Conyza C3-(2003), Hairy fleabane (S. Africa, Spain, Brasil, Columbia, CA)) Urochloa panicoides C4-(2008), Liverseedgrass (Aust- NSW)
  • Herbicide Resistance in Key Glyphosate Resistant Weeds Europe(115) ALS(24) ACCase(13) Photo(63) Glyp(4) Lolium multiflorum - 3 1 1 Lolium rigidum 1 4,1 2,1 5 Bipyridilium(4) Conyza canadensis 1,1 1 8,1 2 Conyza bonarensis 1 - 2 2 Growth Reduction has a Lower Comparing Sensitive Line to the Resistant Line to Dose Response than Survival the label Rate Label Rate 100% Resistant/ Label Rate 75% ~10X 16X Resistant(?) Percent Effect 50% Survival 25% Dry Wgt 4X 0% 0.01 0.1 1 10 100 3 Glyphosate Dose (kg/ha) View slide
  • Weed Resistant Species in Europe 55 C1-Triazine 50 ALS 45 ACCase 40 C2 Urea 35 DNA Species 30 ~90% Target Site Auxins 25 and Metabolism Bipyridil. 20 Glycine 15 10 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 Years of Use View slide
  • Resistance Mechanisms are not Equal in Magnitude or Probability Target Site Mutations • Weak to IMMUNE • ALS, ACCase, •Photosystem 2 •DNA Metabolism Exclusion • Weak Resistance • Weak Resistance; Very Rare •ALS, ACCase, •Active (sequestration) •Photosystem 2 •Passive (cuticle ) •DNA •Most others Combinations Possible 11/6/2008 MONSANTO CONFIDENTIAL 5
  • EPSPS, The Lock and Key Mechanism free EPSP Synthase EPSP Phosphate S-3-P Glyphosate Herbicidal Dead-End Complex PEP busy with chemical CP4 catalysis Doug Sammons Company Confidential Resistant EPSPS, RR
  • Target Site Resistance has 4 Factors 1.) Binding Site Conservation Polymorphic Conserved 2.) Herbicide 3.)Contact Amino 4.) Amino Acid Structure Acids Function Large More Scaffold Small Few Function MONSANTO Unique =high specifity Catalytic 0 CONFIDENTIAL
  • Conserved Amino Acids in EPSPS Consurf: Surface-Mapping of Conservation Glaser, F., T. Pupko, I. Paz, R. E. Bell, D. Bechor-Shental, E. Martz and N. Ben-Tal. Bioinformatics. 19:163-164 (2003).
  • Glyphosate mimics the Tetrahedral Intermediate of the reaction. Schönbrunn et al. 2001, PNAS 98:1376 [EPSPS:Tetrahedral Intermediate] [ EPSPS:S3P:Glyphosate ] 9 complex
  • In Planta Point mutations in EPSPS Consensus Plant Site: G T A M R P L 102 106 Resistant Eleusine indica: G T A M R S L Baerson et al., 2002 Plant Phys. 129:1265 Ng et al., 2004 Aust. J. Ag. Res. 55:407 G T A M R T L Yuan et al., 2005 Plant Prot. Bul. 47:251 G T A M R A L Resistant Lolium rigidum: G T A M R A L Yu et al., 2007 Planta 225:499. Wakelin & Preston, 2006 Weed Res. 46:432. G T A M R T L Resistant Lolium multiflorum: G T A M R S L Perez-Jones et al.,2007 Planta Resistant Oryza sativa: G T A M R L L Zhou et al. 2006 Plant Phys. 140:185 Directed evolution Overall 2-3X Resistance Recorded
  • Metabolic Resistance has 3 Plant factors 1.) Time to Die Based on the 2.) Neutralizing Enz MOA & Species Long More Short Less Mechanism Seed Size Metabolism 3.) Herbicide in the Plant is easier for some Lower Rates Higher Rates Use Rate
  • Glyphosate Can be Metabolized in some Legume sp. Vigna uniguiculata Senna obtusifolia Cassia occidentialis 25% Sesbania herbacea Desmanthus illinoensis 50% Abutilon theophrasti Conyza canadensis O O H Lolium multiflorum C N P C OH HO C H H2 2 OH O H2N P C OH Reddy, K.N., A.M. Rimando, S.O. Duke, and V.K. Nandula. 2008. H2 Aminomethylphosphonic acid accumulation in plant species treated with OH glyphosate. Journal of Agricultural and Food Chemistry 56:2125-2130.
  • Vacuole Hypothesis for Horseweed Resistance MOA Chloroplast Cytoplasm pH ~7 pH ~7 Vacuole pH 4.5-6 Spongy Palisade Mesophyl Cells Cells Dr. Neela Shivakumar and Dr. Cristina Ubach, confocal microscopy
  • 31P NMR Measures Glyphosate pH O O -O P O- N OH H O H P HO O- OH pH 7.0 G Gcyt Gvac vacuole pH 4.5
  • Xia Ge, Andre' d'Avignon, Joseph Ackerman Chemistry Department Washington University, St. Louis, MO USA 11/6/2008 15
  • In vivo 31P-NMR of Horseweed treated with WeatherMAX®. G Sensitive Gcyt Resistant Source Leaves Gvac Source Leaves Gcyt vacuole Gvac Gcyt G Gvac Gcyt G vac vacuole Rapid vacuolar sequestration: the horseweed glyphosate resistance mechanism, Pest Management Science, 66, p 345-348, 2010. Xia Ge, D André d'Avignon, Joseph JH Ackerman, R Douglas Sammons Published Online: Jan 8 2010 9:54AM
  • 8C Resistant Horseweed is sensitive 24 hr when cold 0.5 0.75 1 2 4 8 acclimated 0 lb/a 25C 12 hr 2 hr Resistance mechanism is not ON in the cold 42 DAT
  • Ryegrass also uses the Vacuole for Resistance S332(sensitive) R332(medium) R336 High Glyphosate Resistant Ryegrass, Italy % Mortality 0.34 kg 1.6 kg 7.9 kg ae/ha ae/ha ae/ha Dr. Maurizio Sattin Dr. Alberto Collavo Consiglio Nazionale delle Ricerche Institute of Agro-Environmental and Forest Biology Legnaro, Italy 18
  • Glyphosate Resistant Palmer amaranth in cotton PNAS | January 19, 2010 | V107 | no. 3 | 1029–1034
  • EPSPS Gene Amplification as the Mechanism of Glyphosate Resistance in Palmer amaranthus EPSPS western blot EPSPS genomic copy# Susceptible vs mRNA expression Resistant 1 6 15 39 54 60 copies EPSPS enzyme activity 0.24 0.22 1 copy 0.2 7.5 copies 0.18 (uM Pi / ug / min) EPSPS activity 0.16 39 copies 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0.1 1 10 100 1000 glyphosate (uM)
  • Control +0.75lb S ae/a R 2 DAT Glyphosate resistant Giant Ragweed, Indiana 7 DAT 14 DAT Dr. Steve Weller and Renae Robertson, Purdue University
  • Glyphosate Resistance Mechanisms Exclusion Target Site Extracellular Mutations • Hypersensitive, excission • Pro106X 1 4 2 •Slow across plasmalema 2 2 Over Expression 0 • Copy number • Expression level Intracellular Metabolism • Vacuole accumulation ~8 • Legumes Single gene, Dominant • Very SLOW Combinations Known 22
  • Summary 1.) Glyphosate is Unique 2.) New Mechanisms of Resistance, weaker in magnitude, low dose selection. 3.) Mechanism studies could lead to better management strategies.
  • A Global Commitment To Growing Yield Sustainably® THREE MAIN GOALS ARE AT THE HEART OF THIS EFFORT Help farmers REDUCE by 1/3 the DOUBLE YIELDS inputs required per in corn, cotton & unit of output soybeans by 2030 IMPROVE THE LIVES of farmers around the world
  • Cold Weather Management Horseweed control appears to be 100 % for first 3 application dates. This is the Jan application. Applied another on 2/28/2010 Jan close up 4 Fall applications to Feb Jan Dec Nov horseweed Bob Montgomery, Fall 2009, West TN
  • Weed Resistance Incidents in Europe 140 C1-Triazine (52) ALS 120 ACCase 100 C2 Urea auxins Incidents 80 DNA (2) (4) Bipyridil. 60 (24) (13) Glycine 40 (11) 20 (4) (5) 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 Years of Use
  • Target Site High-level Resistance is Efficiently Selected ACC’ase Resistance fops, dims 1000 • 87% of the herbicide resistance is like this, very high in magnitude Reported 100 • 5 43 casesHerbicide classes are Common NOT controlled, Fold dominated by thisselected resistance IS kind of Resistance resistance 10 •ALS 7 cases < 3X •ACCase Only these cases Ureas controlled •Triazine and can be 1 0 1 Published Data for 48 Cases •Dinitroanilines Gressel, Molecular Biology of Weed Control, Taylor & Francis, London, 2002
  • Crop and Weed Metabolism are Related Genome Sequencing is • Until Biotech, Crop safety revealing how similar plant species are required metabolism • Genomic similarity means weeds have the same metabolism 2 Possibilities 1.) Reaction; Is there enough? Bennetzen and Freeling 1997. 2.) No reaction; requires Genome Research 7:301-306 mutation to gain function 28