Two novel sodium channel mutations associated with resistance to indoxacarb and metaflumizone in the diamondback moth, Plutella xylostella  

作　　者：Xing-Liang Wang Wen Su Jian-Heng Zhang Yi-Hua Yang Ke Dong Yi-Dong Wu 

机构地区：[1]College ofPlantProtection, NanjingAgricultural University, Nanjing, China [2]Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI, USA

出　　处：《Insect Science》2016年第1期50-58,共9页昆虫科学（英文版）

摘　　要：Indoxacarb and metaflumizone belong to a relatively new class of sodium channel blocker insecticides （SCBIs）. Due to intensive use of indoxacarb, field-evolved indoxacarb resistance has been reported in several lepidopteran pests, including the dia- mondback moth Plutella xylostella, a serious pest of cruciferous crops. In particular, the BY 12 population of P. xylostella, collected from Baiyun, Guangdong Province of China in 2012, was 750-fold more resistant to indoxacarb and 70-fold more resistant to metaflu- mizone compared with the susceptible Roth strain. Comparison of complementary DNA sequences encoding the sodium channel genes of Roth and BY12 revealed two point mu- tations （F1845Y and V1848I） in the sixth segment of domain IV of the PxNav protein in the BY population. Both mutations are located within a highly conserved sequence region that is predicted to be involved in the binding sites of local anesthetics and SCBIs based on mammalian sodium channels. A significant correlation was observed among 10 field-collected populations between the mutant allele （Y 1845 or I 1848） frequencies （1.7% to 52.5%） and resistance levels to both indoxacarb （34- to 870-fold） and metaflumizone （1- to 70-fold）. The two mutations were never found to co-exist in the same allele of PxNav, suggesting that they arose independently. This is the first time that sodium channel muta- tions have been associated with high levels of resistance to SCBIs. F 1845Y and V 1848I are molecular markers for resistance monitoring in the diamondback moth and possibly other insect pest species.Indoxacarb and metaflumizone belong to a relatively new class of sodium channel blocker insecticides （SCBIs）. Due to intensive use of indoxacarb, field-evolved indoxacarb resistance has been reported in several lepidopteran pests, including the dia- mondback moth Plutella xylostella, a serious pest of cruciferous crops. In particular, the BY 12 population of P. xylostella, collected from Baiyun, Guangdong Province of China in 2012, was 750-fold more resistant to indoxacarb and 70-fold more resistant to metaflu- mizone compared with the susceptible Roth strain. Comparison of complementary DNA sequences encoding the sodium channel genes of Roth and BY12 revealed two point mu- tations （F1845Y and V1848I） in the sixth segment of domain IV of the PxNav protein in the BY population. Both mutations are located within a highly conserved sequence region that is predicted to be involved in the binding sites of local anesthetics and SCBIs based on mammalian sodium channels. A significant correlation was observed among 10 field-collected populations between the mutant allele （Y 1845 or I 1848） frequencies （1.7% to 52.5%） and resistance levels to both indoxacarb （34- to 870-fold） and metaflumizone （1- to 70-fold）. The two mutations were never found to co-exist in the same allele of PxNav, suggesting that they arose independently. This is the first time that sodium channel muta- tions have been associated with high levels of resistance to SCBIs. F 1845Y and V 1848I are molecular markers for resistance monitoring in the diamondback moth and possibly other insect pest species.

关 键 词：INDOXACARB METAFLUMIZONE MUTATION Plutellaxylostella RESISTANCE sodium channel 

分 类 号：Q754[生物学—分子生物学] TQ453.299[化学工程—农药化工]