College of Plant Protection, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang City 110866, People's Republic of China.
College of Plant Protection, Shenyang Agricultural University, No. 120 Dongling Road, Shenhe District, Shenyang City 110866, People's Republic of China.
Pestic Biochem Physiol. 2024 Sep;204:106038. doi: 10.1016/j.pestbp.2024.106038. Epub 2024 Jul 22.
Weed resistance to a range of herbicides has rapidly evolved, often with different mechanisms of action. The resulting uninhibited growth of weeds poses demonstrable threats to crop production and sustainable agriculture. Digitaria sanguinalis (L.) Scop., a troublesome weed in corn and other agricultural fields, has developed resistance to herbicides that inhibiting ALS (Acetolactate Synthase), such as nicosulfuron. Understanding the weed's resistance patterns and mechanisms is crucial. However, little is known of the non-target site resistance (NTSR) mechanisms of D. sanguinalis owing to a lack of relevant genome sequences and other materials. Therefore, in this study, a population of D.sanguinalis presenting multiple resistance was tested and found that its high level of resistance to ALS-inhibiting herbicides was not associated with target-related alterations.Administration of P450 inhibitors reversed the resistance to ALS-inhibiting herbicides. Following the application of ALS-inhibiting herbicides, the activities of NADPH-P450 reductase and p-nitroanisole O-demethylase (PNOD) were notably greater in the resistant population of D. sanguinalis than those in the susceptible population. The results suggested P450 enzyme familyplays a major role in the metabolic resistance mechanism, that increased P450 enzyme activity promote cross-resistance in D. sanguinalis to ALS-inhibiting herbicides. RNA-seq analysis showed that five genes from the P450 family (CYP709B2, CYP714C2, CYP71A1, CYP76C2, and CYP81E8) were upregulated in resistant D. sanguinalis. In conclusion, the upregulation of several P450 genes is responsible for establishing resistance to ALS-inhibiting herbicides in D. sanguinalis.
杂草对一系列除草剂的抗药性迅速发展，通常具有不同的作用机制。由此产生的杂草不受抑制的生长对作物生产和可持续农业构成了明显的威胁。狗尾草（Digitaria sanguinalis）（L.）Scop. 是玉米和其他农田中的一种棘手杂草，已经对抑制 ALS（乙酰乳酸合酶）的除草剂如烟嘧磺隆产生了抗药性。了解杂草的抗药性模式和机制至关重要。然而，由于缺乏相关的基因组序列和其他材料，对狗尾草的非靶标位点抗性（NTSR）机制知之甚少。因此，在本研究中，对表现出多种抗性的狗尾草种群进行了测试，发现其对 ALS 抑制性除草剂的高水平抗性与靶标相关变化无关。P450 抑制剂的给药逆转了对 ALS 抑制性除草剂的抗性。在施用 ALS 抑制性除草剂后，抗性狗尾草种群中 NADPH-P450 还原酶和对硝基苯甲醚 O-脱甲基酶（PNOD）的活性明显高于敏感种群。结果表明，P450 酶家族在代谢抗性机制中起主要作用，增加 P450 酶活性促进了狗尾草对 ALS 抑制性除草剂的交叉抗性。RNA-seq 分析表明，来自 P450 家族的五个基因（CYP709B2、CYP714C2、CYP71A1、CYP76C2 和 CYP81E8）在抗性狗尾草中上调。总之，几个 P450 基因的上调负责建立狗尾草对 ALS 抑制性除草剂的抗性。
