柑桔全爪螨噻螨酮抗性与敏感品系GST基因表达差异分析

Differential Analysis of Glutathione S-transferase Genes Expression in Citrus Red Mite between Resistant and Susceptible Strains to Hexythiazox

为了明确谷胱甘肽S-转移酶(glutathion S-transferases,GSTs)基因与柑桔全爪螨Panony-chus citri抗性的关系,通过BLAST搜索,对柑桔全爪螨转录组数据库的GST基因进行鉴定,进一步采用RPKM法分析柑桔全爪螨噻螨酮敏感品系(SS)和抗性品系(RS)的GST基因表达差异。从柑桔全爪螨转录组中获得了30条GST基因,11条基因属于Delta家族,10条属于Mu家族,6条属于Kappa家族,2条属于Omega家族,1条属于Zeta家族,同一家族的基因聚在同一进化分支上;两个品系有5条GST基因表达没有差异,此外,抗性品系中有16条发生了下调,有9条GST基因发生了上调;抗性品系上调倍数最高的3个GST基因分别是GSTd6、GSTm5和GSTm4,log_2(RPKM_(RS)/RPKM_(SS))分别仅为1.05、0.74和0.71,荧光定量PCR分析测得上调倍数分别仅为1.13、1.42和1.21,上调倍数均不高。推断,GST基因上调可能不是柑桔全爪螨对噻螨酮产生抗性的重要原因。

In order to clarify the relationship between glutathione S-transferase （GST） gene and resistance of Panonychus cirri to Hexythiazox, GST genes were identified from the P. citri transcriptorne database by BLAST searching. Phylogenetic tree was constructed by MEGA4. 0. 1. Oene expression profiles of GST genes in related to resistant and susceptible to Hexythiazox were compared using RPKM （Reads Per Kilobase of exon model per Million mapped reads） method. Of 30 GST genes were found in transcripts of P. cirri. The results ＇of gene expression difference analysis indicated that 9 GST genes were up-regulated and 16 GST genes were dowwregulated in the resistant strain, of which GSTd6, GSTm5 and GSTrrd l-log2 Ratio（RS/SS）were 1.05, 0. 74 and O. 71, respectively] were the top three up-regulated GST genes. Further gene expression analysis using real-time PCR indicated that GSTd6, GSTm5 and GSTrn4 had only 1.13, 1.42 and 1.21 fold of up regulation in resistant strain, respectively. The above results indicated that up regulation ofGST genes may not play an important role in hexythiazox resistance of P. cirri.