Han Heping, Vila-Aiub Martin M, Jalaludin Adam, Yu Qin, Powles Stephen B
Australian Herbicide Resistance Initiative (AHRI)-School of Agriculture and Environment, University of Western Australia (UWA), Perth, Australia.
IFEVA-CONICET-Faculty of Agronomy, Department of Ecology, University of Buenos Aires (UBA), Buenos Aires, Argentina.
Plant Cell Environ. 2017 Dec;40(12):3031-3042. doi: 10.1111/pce.13067. Epub 2017 Oct 6.
A novel glyphosate resistance double point mutation (T102I/P106S, TIPS) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene has been recently identified for the first time only in the weed species Eleusine indica. Quantification of plant resistance cost associated with the TIPS and the often reported glyphosate resistance single P106S mutation was performed. A significant resistance cost (50% in seed number currency) associated with the homozygous TIPS but not the homozygous P106S EPSPS variant was identified in E. indica plants. The resistance cost associated with the TIPS mutation escalated to 85% in plants under resource competition with rice crops. The resistance cost was not detected in nonhomozygous TIPS plants denoting the recessive nature of the cost associated with the TIPS allele. An excess of 11-fold more shikimate and sixfold more quinate in the shikimate pathway was detected in TIPS plants in the absence of glyphosate treatment compared to wild type, whereas no changes in these compounds were observed in P106S plants when compared to wild type. TIPS plants show altered metabolite levels in several other metabolic pathways that may account for the expression of the observed resistance cost.
最近首次在杂草物种稗草中鉴定出5-烯醇丙酮酸莽草酸-3-磷酸合酶（EPSPS）基因中的一种新型抗草甘膦双点突变（T102I/P106S，TIPS）。对与TIPS相关的植物抗性代价以及经常报道的草甘膦抗性单P106S突变进行了量化。在稗草植株中，鉴定出与纯合TIPS相关的显著抗性代价（以种子数量计为50%），但与纯合P106S EPSPS变体无关。在与水稻作物资源竞争的情况下，与TIPS突变相关的抗性代价在植株中升至85%。在非纯合TIPS植株中未检测到抗性代价，这表明与TIPS等位基因相关的代价具有隐性性质。与野生型相比，在未进行草甘膦处理的情况下，TIPS植株中莽草酸途径中的莽草酸过量11倍以上，奎尼酸过量6倍，而与野生型相比，P106S植株中这些化合物没有变化。TIPS植株在其他几种代谢途径中显示出代谢物水平的改变，这可能解释了观察到的抗性代价的表达。
