Planta

, Volume 239, Issue 4, pp 793–801

No fitness cost of glyphosate resistance endowed by massive EPSPS gene amplification in Amaranthus palmeri

  • Martin M. Vila-Aiub
  • Sou S. Goh
  • Todd A. Gaines
  • Heping Han
  • Roberto Busi
  • Qin Yu
  • Stephen B. Powles
Original Article

DOI: 10.1007/s00425-013-2022-x

Cite this article as:
Vila-Aiub, M.M., Goh, S.S., Gaines, T.A. et al. Planta (2014) 239: 793. doi:10.1007/s00425-013-2022-x

Abstract

Amplification of the EPSPS gene has been previously identified as the glyphosate resistance mechanism in many populations of Amaranthus palmeri, a major weed pest in US agriculture. Here, we evaluate the effects of EPSPS gene amplification on both the level of glyphosate resistance and fitness cost of resistance. A. palmeri individuals resistant to glyphosate by expressing a wide range of EPSPS gene copy numbers were evaluated under competitive conditions in the presence or absence of glyphosate. Survival rates to glyphosate and fitness traits of plants under intra-specific competition were assessed. Plants with higher amplification of the EPSPS gene (53-fold) showed high levels of glyphosate resistance, whereas less amplification of the EPSPS gene (21-fold) endowed a lower level of glyphosate resistance. Without glyphosate but under competitive conditions, plants exhibiting up to 76-fold EPSPS gene amplification exhibited similar height, and biomass allocation to vegetative and reproductive organs, compared to glyphosate susceptible A. palmeri plants with no amplification of the EPSPS gene. Both the additive effects of EPSPS gene amplification on the level of glyphosate resistance and the lack of associated fitness costs are key factors contributing to EPSPS gene amplification as a widespread and important glyphosate resistance mechanism likely to become much more evident in weed plant species.

Keywords

Evolution Fitness traits Gene over-expression Herbicide resistance Target-site resistance Weeds 

Abbreviations

ALS

Acetolactate synthase

DAT

Days after treatment

EPSPS

5-Enolpyruvylshikimate-3-phosphate synthase

LD50

Lethal dose fifty

PCR

Polymerasa chain reaction

R

Glyposate resistant

S

Glyphosate susceptible

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Martin M. Vila-Aiub
    • 1
    • 2
  • Sou S. Goh
    • 1
  • Todd A. Gaines
    • 1
  • Heping Han
    • 1
  • Roberto Busi
    • 1
  • Qin Yu
    • 1
  • Stephen B. Powles
    • 1
  1. 1.Australian Herbicide Resistance Initiative (AHRI)-School of Plant BiologyUniversity of Western Australia (UWA)CrawleyAustralia
  2. 2.Facultad de Agronomía, Departamento de Ecología, IFEVA-CONICETUniversidad de Buenos Aires (UBA)Buenos AiresArgentina