Anhui Province Key Laboratory of Crop Integrated Pest Management, School of Plant Protection, Anhui Agricultural University, Hefei, China.
Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, China.
Pest Manag Sci. 2022 Mar;78(3):1164-1175. doi: 10.1002/ps.6733. Epub 2021 Dec 9.
Metabolic resistance is a worldwide concern for weed control but has not yet been well-characterized at the genetic level. Previously, we have identified an Asia minor bluegrass (Polypogon fugax Nees ex Steud.) population AHHY exhibiting cytochrome P450 (P450)-involved metabolic resistance to fenoxaprop-P-ethyl. In this study, we aimed to confirm the metabolic fenoxaprop-P-ethyl resistance in AHHY and uncover the potential herbicide metabolism-related genes in this economically damaging weed species.
Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays indicated the metabolic rates of fenoxaprop-P-ethyl were significantly faster in resistant (R, AHHY) than in susceptible (S, SDTS) plants. The amount of phytotoxic fenoxaprop-P peaked at 12 h after herbicide treatment (HAT) and started to decrease at 24 HAT in both biotypes. R and S plants at 24 HAT were sampled to conduct isoform-sequencing (Iso-Seq) and RNA-sequencing (RNA-Seq). A reference transcriptome containing 24 972 full-length isoforms was obtained, of which 24 329 unigenes were successfully annotated. Transcriptomic profiling identified 28 detoxifying enzyme genes constitutively and/or herbicide-induced up-regulated in R than in S plants. Real-time quantitative polymerase chain reaction (RT-qPCR) confirmed 17 genes were consistently up-regulated in R and its F1 generation plants. They were selected as potential fenoxaprop-P-ethyl metabolism-related genes, including ten P450s, one glutathione-S-transferase, one UDP-glucosyltransferase, and five adenosine triphosphate (ATP)-binding cassette transporters.
This study revealed that the enhanced rates of fenoxaprop-P-ethyl metabolism in P. fugax were very likely driven by the herbicide metabolism-related genes. The transcriptome data generated by Iso-Seq combined with RNA-Seq will provide abundant gene resources for understanding the molecular mechanisms of resistance in P. fugax.
代谢抗性是全球杂草防治关注的一个问题，但尚未在遗传水平上得到很好的描述。以前，我们已经鉴定出一个亚洲小蓝草（Polypogon fugax Nees ex Steud.）种群 AHHY，其对 Fenoxaprop-P-ethyl 表现出细胞色素 P450（P450）参与的代谢抗性。在这项研究中，我们旨在确认 AHHY 中代谢 Fenoxaprop-P-ethyl 的抗性，并揭示这种具有经济破坏性杂草物种中潜在的除草剂代谢相关基因。
液相色谱-串联质谱（LC-MS/MS）分析表明，抗性（AHHY）植物中 Fenoxaprop-P-ethyl 的代谢速度明显快于敏感（SDTS）植物。在两种生物型中，在施药后 12 小时（HAT）达到了最大的除草活性 Fenoxaprop-P 含量，并在 24 HAT 开始下降。在 24 HAT 时，采集 R 和 S 植株进行同工型测序（Iso-Seq）和 RNA 测序（RNA-Seq）。获得了包含 24972 个全长同工型的参考转录组，其中 24329 个 unigenes 成功注释。转录组分析鉴定出 28 种解毒酶基因在 R 中组成型和/或诱导上调，而在 S 中则下调。实时定量聚合酶链反应（RT-qPCR）证实，在 R 及其 F1 代植物中，有 17 个基因持续上调。它们被选为潜在的 Fenoxaprop-P-ethyl 代谢相关基因，包括 10 个 P450s、1 个谷胱甘肽-S-转移酶、1 个 UDP-葡萄糖基转移酶和 5 个三磷酸腺苷（ATP）结合盒转运蛋白。
本研究表明，P. fugax 中 Fenoxaprop-P-ethyl 代谢率的提高很可能是由与除草剂代谢相关的基因驱动的。Iso-Seq 与 RNA-Seq 相结合产生的转录组数据将为理解 P. fugax 抗性的分子机制提供丰富的基因资源。
