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Evaluation of glyphosate resistance in Arabidopsis thaliana expressing an altered target site EPSPS
Author(s) -
Sammons R Douglas,
You Jinsong,
Qi Youlin,
Flasinski Stanislaw,
Kavanaugh Christina,
Washam Jeannie,
Ostrander Elizabeth,
Wang Dafu,
Heck Greg
Publication year - 2018
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.4654
Subject(s) - biology , glyphosate , arabidopsis thaliana , weed , pesticide resistance , transgene , mutant , herbicide resistance , pest analysis , genetically modified crops , genetics , botany , gene , pesticide , microbiology and biotechnology , agronomy
BACKGROUND Glyphosate‐resistant goosegrass has recently evolved and is homozygous for the double mutant of EPSPS (T 102 I, P 106 S or TIPS). These same mutations combined with EPSPS overexpression, have been used to create transgenic glyphosate‐resistant crops. Arabidopsis thaliana (Wt EPSPS K i ∼ 0.5 μM) was engineered to express a variant At EPSPS‐T 102 I, P 106 A (TIPA K i = 150 μM) to determine the resistance magnitude for a more potent variant EPSPS that might evolve in weeds. RESULTS Transgenic A. thaliana plants, homozygous for one, two or four copies of At EPSPS‐TIPA, had resistance (IC 50 values, R/S) as measured by seed production ranging from 4.3‐ to 16‐fold. Plants treated in reproductive stage were male sterile with a range of R/S from 10.1‐ to 40.6‐fold. A significant hormesis (∼ 63% gain in fresh weight) was observed for all genotypes when treated at the initiation of reproductive stage with 0.013 kg ha –1 . At EPSPS‐TIPA enzyme activity was proportional to copy number and correlated with resistance magnitude. CONCLUSIONS A. thaliana , as a model weed expressing one copy of At EPSPS‐TIPA (300‐fold more resistant), had only 4.3‐fold resistance to glyphosate for seed production. Resistance behaved as a single dominant allele. Vegetative tissue resistance was 4.7‐fold greater than reproductive tissue resistance and was linear with gene copy number. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.