柑橘全爪螨代谢抗性相关基因表达差异分析

Analysis of expression difference of metabolism genes in Panonychus citri

【目的】为了明确谷胱甘肽S-转移酶(GST)基因、羧酸酯酶(CarE)基因,过氧化氢酶(CAT)基因在柑橘全爪螨Panonychus citri抗性中的作用,【方法】在室内用噻螨酮对柑橘全爪螨进行抗性选育,进一步构建抗/敏品系数字基因表达谱,采用RPKM法对柑橘全爪螨敏感品系和噻螨酮抗性品系3种代谢抗性相关基因进行表达差异分析。【结果】经过20代抗性选育,获得了柑橘全爪螨噻螨酮抗性品系,与敏感品系比较,柑橘全爪螨对噻螨酮的抗性倍数达到3 532.12倍。基因差异性分析发现,抗性品系中有11条GST基因、17条CarE基因和6条CAT基因表达上调;14条GST基因、24条CarE基因和3条CAT基因表达下调。上调倍数最高的GST基因、CarE基因和CAT基因分别为Unigene31530[log2 ratio(RS/SS)=1.05]、Unigene23121[log2 ratio(RS/SS)=2.05]和Unigene31477[log2 ratio(RS/SS)=10.04]。进一步对Unigene31477进行荧光定量PCR分析发现,抗性和敏感品系基因表达水平没有显著差异。【结论】根据柑橘全爪螨抗/敏性品系基因表达差异推断,GST、CarE和CAT基因可能与柑橘全爪螨对噻螨酮产生的抗性没有密切关系。

【Objective】To clarify the relationship among expression level of glutathione S-transferase（GST）,Carboxylesterase（CarE）,and Catalase（CAT） genes and resistance of P.citri,【Method】Resistance selection was conducted in laboratory and gene expression profiles of GST,CarE,and CAT gene between the resistant strain and susceptible strain were compared using Reads Per kb per Million reads（RPKM） method.【Result】After selection with hexythiazox continuously for 20 generations,a resistant strain was obtained with the resistance ratio（R/S） of 3532.12 compared with the susceptible strain.Analysis results of gene expression difference indicated that 11 GST genes,17 CarE genes and 6 CAT genes were up-regulated,while 14 GST genes,24 CarE genes and 3 CAT genes were down-regulated in resistant strain.Unigene31530[log2 ratio（RS/SS）=1.05],Unigene23121[log2 ratio（RS/SS）=2.05],and Unigene31477 [log2 ratio（RS/SS）=10.04] were the top up-regulated GST gene,CarE gene and CAT gene,respectively.Further gene expression analysis using real-time PCR indicated that there was not significant difference in expression level of Unigene31477 between the resistant strain and susceptible strain.【Conclusion】Judging from gene expression differences between resistant and susceptible strains of P.citri,we concluded that up-regulation of GST,CarE and CAT genes may not play an important role in hexythiazox resistance of P.citri.