This AHRI insight is not for the faint-hearted. This recent AHRI research by Chinese postdoc Hongju Ma and others documents the first case of metabolic resistance to metribuzin in ryegrass in Australia. The ryegrass in this population was only about 3 fold resistant to Atrazine and Metribuzin. The researchers used a P450 inhibitor, PBO, and radiolabelled metribuzin to help determine that the resistance is metabolism-based, likely due to P450 enzyme activity.   

This AHRI insight is not for the faint-hearted. It is the work of AHRI researcher, Dr Danica Goggin who has dedicated many years to working out how auxin herbicides such as 2,4-D and Dicamba work, and how plants evolve resistance to them. Danica’s research found that plants with fewer receptors on their cell membranes were resistant to 2,4-D due to reduced perception of the 2,4-D. Putting this molecular biology research into words is challenging, so we have created some videos that explain it.