Bao Wen Xue, Narai Yutaka, Nakano Akio, Kaneda Takemichi, Murai Tamotsu, Sonoda Shoji
Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan.
Shimane Agricultural Technology Center, Izumo, Shimane 693-0035, Japan.
Pestic Biochem Physiol. 2014 Jun;112:51-5. doi: 10.1016/j.pestbp.2014.04.013. Epub 2014 May 9.
To examine the resistance mechanisms of Thrips palmi against spinosad, we cloned partial nucleotide sequences of the nicotinic acetylcholine receptor α6 subunit (TPα6) gene from susceptible (OK) and resistant (TS1 and TS5) strains and compared the deduced amino acid sequences among the three strains. The OK, TS1, and TS5 strains respectively showed LC50 values of 3.4mg/L, 2838.5mg/L, and 6655.5mg/L. The deduced amino acid sequence of TPα6 gene showed 96% identity with that of Frankliniella occidentalis. Comparison of the deduced amino acid sequences of TPα6 gene among the three strains showed that the TS1 and TS5 strains had a resistant amino acid, Glu, at amino acid position 275. On the other hand, a susceptible amino acid, Gly, was encoded at the corresponding amino acid position for the OK strain. The synergist, piperonyl butoxide, respectively caused 1.1-fold , 5.8-fold , and 9.0-fold decreases in the resistance ratios of the OK, TS1, and TS5 strains. These results suggest that spinosad resistance of T. palmi is conferred by reduced sensitivity of TPα6 and cytochrome P450-mediated detoxification.
为研究棕榈蓟马对多杀菌素的抗性机制，我们从敏感品系（OK）和抗性品系（TS1和TS5）中克隆了烟碱型乙酰胆碱受体α6亚基（TPα6）基因的部分核苷酸序列，并比较了这三个品系推导的氨基酸序列。OK、TS1和TS5品系的LC50值分别为3.4mg/L、2838.5mg/L和6655.5mg/L。TPα6基因推导的氨基酸序列与西花蓟马的该序列有96%的同一性。三个品系TPα6基因推导的氨基酸序列比较表明，TS1和TS5品系在第275位氨基酸处有一个抗性氨基酸Glu。另一方面，OK品系在相应氨基酸位置编码的是敏感氨基酸Gly。增效剂胡椒基丁醚分别使OK、TS1和TS5品系的抗性倍数降低了1.1倍、5.8倍和9.0倍。这些结果表明，棕榈蓟马对多杀菌素的抗性是由TPα6敏感性降低和细胞色素P450介导的解毒作用所致。
