Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China.
Sci Rep. 2017 Nov 27;7(1):16380. doi: 10.1038/s41598-017-16655-0.
D. Sophia is one of the most problematic weed species infesting winter wheat in China, and has evolved high resistance to tribenuron-methyl. Amino acid substitutions at site of Pro197, Asp376 and Trp574 in acetohydroxyacid synthase (AHAS) were mainly responsible for D. sophia resistance to tribenuron-methyl. In this study, D. sophia plant individually homozygous for specific AHAS mutation (Pro197Leu, Pro197His, Pro197Ser, Pro197Thr, Asp376Glu and Trp574Leu) were generated. In addition, the effects of resistance mutations on pigments, growths and competitiveness of susceptible (S) and resistant (R) plants of D. sophia were investigated. The results indicated the R plants carrying Pro197Leu or Pro197His or Asp376Glu or Trp574Leu displayed stronger competitiveness than S plants. The adverse effects on R plants aggravated with the increase of R plants proportion, which made the R plants against domination the weed community in absent of herbicide selection. Therefore, these resistance mutation have no obvious adverse effects on the pigments (chlorophyll a, chlorophyll b and carotenoid), relative growth rates (RGR), leaf area ratio (LAR) and net assimilation rate (NAR) of R plants.
节节麦是中国冬小麦上一种极具危害性的杂草，已经对唑嘧磺草胺产生了高水平的抗性。乙酰羟酸合酶（AHAS）中位于 Pro197、Asp376 和 Trp574 位点的氨基酸取代主要导致了节节麦对唑嘧磺草胺的抗性。本研究中，通过对单个节节麦植株进行基因编辑，获得了特异性的 AHAS 突变（Pro197Leu、Pro197His、Pro197Ser、Pro197Thr、Asp376Glu 和 Trp574Leu）纯合植株。此外，还研究了抗性突变对敏感型（S）和抗性型（R）节节麦植株的色素、生长和竞争力的影响。结果表明，携带 Pro197Leu 或 Pro197His 或 Asp376Glu 或 Trp574Leu 抗性突变的 R 植株比 S 植株具有更强的竞争力。随着 R 植株比例的增加，R 植株对杂草群落的竞争优势也随之增强，这使得在没有除草剂选择的情况下，R 植株会对杂草群落的主导地位产生不利影响。因此，这些抗性突变对 R 植株的色素（叶绿素 a、叶绿素 b 和类胡萝卜素）、相对生长率（RGR）、叶面积比（LAR）和净同化率（NAR）没有明显的不利影响。
