Evolution of a Double Amino Acid Substitution in the 5-Enolpyruvylshikimate-3-Phosphate Synthase in Eleusine indica Conferring High-Level Glyphosate Resistance1
Naturally evolved double mutants in 5-enolpyruvylshikimate-3-phosphate synthase mimic engineered glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate synthase in crops and confer high-level glyphosate resistance. Glyphosate is the most important and widely used herbicide in world agriculture. Inte...
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Published in | Plant physiology (Bethesda) Vol. 167; no. 4; pp. 1440 - 1447 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
American Society of Plant Biologists
25.02.2015
|
Online Access | Get full text |
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Summary: | Naturally evolved double mutants in 5-enolpyruvylshikimate-3-phosphate synthase mimic engineered glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate synthase in crops and confer high-level glyphosate resistance.
Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant
Eleusine indica
population, we identified a double amino acid substitution (T102I + P106S [
TIPS
]) in the 5-enolpyruvylshikimate-3-phosphate synthase (
EPSPS
) gene in glyphosate-resistant individuals. This
TIPS
mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant
EPSPS
in corn (
Zea mays
) and now in other crops. In
E. indica
, the naturally evolved
TIPS
mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The
E. indica
TIPS
EPSPS
showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the
TIPS
mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant
TIPS
EPSPS
. The sequential evolution of the
TIPS
mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. |
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Bibliography: | The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Stephen B. Powles (stephen.powles@uwa.edu.au). www.plantphysiol.org/cgi/doi/10.1104/pp.15.00146 |
ISSN: | 0032-0889 1532-2548 |
DOI: | 10.1104/pp.15.00146 |