non-target-site resistance

This Special Issue of Plants comprises papers that describe the current status and future outlook of herbicide resistance research and development in weedy and domestic plants, with topics covering the full spectrum from resistance mechanisms to resistance management.

Herbicide resistance in weeds is perhaps the most prominent research area within the discipline of weed science today. Incidence, management challenges, and the cost of multiple-resistant weed populations are continually increasing worldwide.

Earlier papers by Gaines et al 2012 Weed Technology and Goh et al 2016 Pest Management Science, documented a glyphosate resistance Echinochloa population from the irrigated north-west Ord River irrigation region of Western Australia. AHRI PhD student Sou Sheng Goh studied this population for his PhD research. Among other studies, Goh completed excellent work to identify the mechanistic basis of glyphosate resistance in this Echinochloa population. Goh examined for but did not find EPSPS resistance gene mutations and/or EPSPS gene amplification. Thus Goh established that glyphosate resistance in this particular resistant biotype is NON-target site based. 

In a large cropping area of northern Argentina, Sorghum halepense (Johnsongrass) has evolved towards glyphosate resistance. This study aimed to determine the molecular and biochemical basis conferring glyphosate resistance in this species. Experiments were conducted to assess target EPSPS gene sequences and 14C-glyphosate leaf absorption and translocation to meristematic tissues.

Narrow-leafed lupin (Lupinus angustifolius L.) is an important grain legume crop in Australia. Metribuzin is an important herbicide used to control weeds in lupin crops. This study investigated metribuzin tolerance mechanism in narrow-leafed lupin by comparing two induced mutants (Tanjil-AZ-33 and Tanjil-AZ-55) of higher metribuzin tolerance with the susceptible wild type.