Wang Kang, Peng Xiong, Zuo Yayun, Li Yuting, Chen Maohua
College of Plant Protection, Northwest A&F University, Yangling, China.
Key Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Yangling, China.
PLoS One. 2016 Apr 28;11(4):e0154633. doi: 10.1371/journal.pone.0154633. eCollection 2016.
NADPH-cytochrome P450 reductase (CPR) plays an important role in the cytochrome P450 (CYP)-mediated metabolism of endogenous and exogenous substrates. CPR has been found to be associated with insecticide metabolism and resistance in many insects. However, information regarding CPR in the bird cherry-oat aphid, Rhopalosiphum padi, is unavailable. In the current study, a full-length cDNA (2,476 bp) of CPR (RpCPR) encoding 681 amino acids was cloned from R. padi. Nucleotide sequence and deduced amino acid sequence analysis showed that RpCPR exhibits characteristics of classical CPRs and shares high identities with those of other insects, especially with the pea aphid, Acyrthosiphon pisum. The mRNA of RpCPR was expressed at all developmental stages, with the highest expression level found in the second instar and the lowest in adult. Expression levels of RpCPR in isoprocarb-resistant and imidacloprid-resistant strains were 3.74- and 3.53-fold higher, respectively, than that of a susceptible strain. RpCPR expression could also be induced by low concentrations (LC30) of isoprocarb and imidacloprid. Moreover, we sequenced the open reading frame (ORF) of RpCPR from 167 field samples collected in 11 geographical populations. Three hundred and thirty-four SNPs were detected, of which, 65 were found in more than two individuals. One hundred and ninety-four missense mutations were present in the amino acid sequence, of which, the P484S mutant had an allele frequency of 35.1%. The present results suggest that RpCPR may play an important role in the P450-mediated insecticide resistance of R. padi to isoprocarb and imidacloprid and possibly other insecticides. Meanwhile, RpCPRmaintains high genetic diversity in natural individuals, which provides the possibility of studying potential correlations between variants and certain special physiological characters.
烟酰胺腺嘌呤二核苷酸磷酸细胞色素P450还原酶（CPR）在细胞色素P450（CYP）介导的内源性和外源性底物代谢中发挥着重要作用。在许多昆虫中，CPR已被发现与杀虫剂代谢及抗性相关。然而，关于鸟樱桃燕麦蚜（Rhopalosiphum padi）中CPR的信息尚不可知。在本研究中，从鸟樱桃燕麦蚜中克隆到了一个编码681个氨基酸的CPR（RpCPR）全长cDNA（2476 bp）。核苷酸序列和推导的氨基酸序列分析表明，RpCPR具有经典CPR的特征，并且与其他昆虫的CPR具有高度同源性，尤其是与豌豆蚜（Acyrthosiphon pisum）。RpCPR的mRNA在所有发育阶段均有表达，其中在二龄若虫期表达水平最高，在成虫期最低。抗异丙威和抗吡虫啉品系中RpCPR的表达水平分别比敏感品系高3.74倍和3.53倍。低浓度（LC30）的异丙威和吡虫啉也可诱导RpCPR的表达。此外，我们对从11个地理种群采集的167个田间样本中的RpCPR开放阅读框（ORF）进行了测序。共检测到334个单核苷酸多态性（SNP），其中65个在两个以上个体中被发现。氨基酸序列中存在194个错义突变，其中P484S突变体的等位基因频率为35.1%。目前的结果表明，RpCPR可能在鸟樱桃燕麦蚜对异丙威和吡虫啉以及可能对其他杀虫剂的P450介导的抗性中发挥重要作用。同时，RpCPR在自然个体中保持着较高的遗传多样性，这为研究变异体与某些特殊生理特征之间的潜在相关性提供了可能性。
