The first reported occurrence of EPSPS gene amplification in a field-evolved weed species was a glyphosate-resistant (GR) Amaranthus palmeri population from Georgia, USA.  The additional EPSPS gene copies were inserted on all chromosomes.  Subsequently GR A. palmeri populations have been reported from three additional states with EPSPS gene amplification from 2- to 63-fold.  Additional species have been reported with EPSPS gene amplification in GR populations, including Lolium multiflorum, Bromus diandrus, Kochia scoparia, A. tuberculatus, and A. spinosus.  In A. palmeri, L. multiflorum, and K. scoparia populations, EPSPS mRNA expression and EPSPS protein levels have a linear correlation with EPSPS genomic copy number.  Two recent studies have reported no fitness penalty in GR A. palmeri with EPSPS gene amplification.  This glyphosate resistance mechanism is becoming increasingly widespread.  Gene amplification can occur through unequal crossing over events, and/or transposable element activity, and these hypotheses are being tested in GR species.

Update on <i>EPSPS</i> gene amplification in glyphosate-resistant weeds

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Update on EPSPS gene amplification in glyphosate-resistant weeds