College of Plant Protection, Shandong Agricultural University, Shandong Province Higher Education Provincial Key Pesticide Toxicology and Application Technology Laboratory, Tai'an 271018 Shandong, People's Republic of China.
College of Plant Protection, Shandong Agricultural University, Tai'an 271018 Shandong, People's Republic of China.
J Agric Food Chem. 2024 Jun 26;72(25):14402-14410. doi: 10.1021/acs.jafc.4c02723. Epub 2024 Jun 14.
Tripyrasulfone is currently the only HPPD-inhibiting herbicide that possesses outstanding selectivity even for direct-seeded rice () when applied POST to control grass weeds; however, the underlying mechanisms remain unclear. In this study, the inhibitory effects of the real active HDT of tripyrasulfone on recombinant 4-hydroxyphenylpyruvate dioxygenase (HPPDs) from rice and barnyard grass () were similar, with consistent structural interactions and similar binding energies predicted by molecular docking. However, the HPPD expression level in rice was significantly greater than that in barnyard grass after tripyrasulfone treatment. Tripyrasulfone was rapidly taken up and hydrolyzed into HDT, which was similarly distributed within the whole plants of rice and barnyard grass at 24 h after treatment. Compared with barnyard grass, rice has more uniform epicuticular wax in the cuticle of its leaves, absorbing less tripyrasulfone and metabolizing much more tripyrasulfone. Overall, to a greater extent, the different sensitivities to tripyrasulfone between barnyard grass and rice resulted from metabolic variations.
三唑并嘧啶砜是目前唯一一种 HPPD 抑制剂除草剂，即使在 POST 施用于直播稻时，也具有出色的选择性，可用于防除杂草；然而，其作用机制尚不清楚。在这项研究中，三唑并嘧啶砜的实际活性代谢物 HDT 对水稻和稗草重组 4- 羟苯基丙酮酸双加氧酶 (HPPD) 的抑制作用相似，通过分子对接预测出一致的结构相互作用和相似的结合能。然而，在三唑并嘧啶砜处理后，水稻中的 HPPD 表达水平明显高于稗草。三唑并嘧啶砜被迅速吸收并水解成 HDT，在处理后 24 小时内，HDT 在水稻和稗草的整株植物中分布相似。与稗草相比，水稻叶片角质层中的表皮蜡更均匀，吸收的三唑并嘧啶砜较少，代谢的三唑并嘧啶砜更多。总的来说，稗草和水稻对三唑并嘧啶砜的敏感性差异在更大程度上是由于代谢的差异。
