Pedroso Rafael M, Al-Khatib Kassim, Alarcón-Reverte Rocio, Fischer Albert J
Department of Plant Sciences, University of California, Davis, CA, USA.
Pest Manag Sci. 2016 Sep;72(9):1673-80. doi: 10.1002/ps.4267. Epub 2016 Apr 6.
Propanil-resistant (R) Cyperus difformis populations were recently confirmed in California rice fields. To date, propanil resistance in other weed species has been associated with enhanced aryl acylamidase (AAA)-mediated propanil conversion into 3,4-dichloroaniline. Our objectives were to determine the level of propanil resistance and cross-resistance to other PSII inhibitors in C. difformis lines, and to elucidate the mechanism of propanil resistance.
The propanil-R line had a 14-fold propanil resistance and increased resistance to bromoxynil, diuron and metribuzin, but not to atrazine. The R line, however, displayed a fourfold increased susceptibility to bentazon. Interestingly, susceptible (S) plants accumulated more 3,4-dichloroaniline and were more injured by propanil and carbaryl (AAA-inhibitor) applications than R plants, suggesting that propanil metabolism is not the resistance mechanism. psbA gene sequence analysis indicated a valine-219-isoleucine (Val219 Ile) amino acid exchange in the propanil-R chloroplast D1 protein.
The D1 Val219 Ile modification in C. difformis causes resistance to propanil, diuron, metribuzin and bromoxynil but increased susceptibility to bentazon, suggesting that the Val219 residue participates in binding of these herbicides. This is the first report of a higher plant exhibiting target-site propanil resistance. Tank mixing of bentazon and propanil, where permitted, can control both propanil-R and propanil-S C. difformis and prevent the spread of the resistant phenotype. © 2016 Society of Chemical Industry.
最近在加利福尼亚州稻田中确认了对敌稗具有抗性（R）的异型莎草种群。迄今为止，其他杂草物种中的敌稗抗性与芳基酰胺酶（AAA）介导的敌稗转化为3,4-二氯苯胺增强有关。我们的目标是确定异型莎草品系中敌稗抗性水平以及对其他光合系统II抑制剂的交叉抗性，并阐明敌稗抗性机制。
抗敌稗品系对敌稗具有14倍的抗性，对溴苯腈、敌草隆和嗪草酮的抗性增强，但对莠去津不具有抗性。然而，该抗性品系对苯达松的敏感性增加了四倍。有趣的是，敏感（S）植株比抗性（R）植株积累了更多的3,4-二氯苯胺，并且在施用敌稗和西维因（AAA抑制剂）时受到的伤害更大，这表明敌稗代谢不是抗性机制。psbA基因序列分析表明，抗敌稗叶绿体D1蛋白中存在缬氨酸-219-异亮氨酸（Val219 Ile）氨基酸交换。
异型莎草中D1蛋白的Val219 Ile修饰导致对敌稗、敌草隆、嗪草酮和溴苯腈具有抗性，但对苯达松的敏感性增加，这表明Val219残基参与了这些除草剂的结合。这是关于高等植物表现出靶标位点敌稗抗性的首次报道。在允许的情况下，将苯达松和敌稗进行桶混，可以控制抗敌稗和敏感型异型莎草，并防止抗性表型的传播。©2016化学工业协会。
