Australian study finds glyphosate resistance mechanism in brome
Researchers in Australia have shown that resistance to the herbicide, glyphosate, in two populations of great brome (Bromus diandrus) has been caused by gene amplification. Both populations showed amplification of a gene coding for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), with resistant plants having an average of 20 times the number of EPSPS copies compared with susceptible plants. EPSPS expression was increased in resistant plants in both populations, but expression levels were not correlated with the number of EPSPS copies. The research was conducted at the University of Adelaide. Associate professor Christopher Preston, who led the research, says that it underlines the importance of using diverse practices for brome management to reduce the risk of resistance developing. "The bad news for farmers is that brome is another weed that will become increasingly harder to control," he says. The study has been published in Pest Management Science.