嗜卷书虱Cu/Zn-SOD1,Cu/Zn-SOD2和Fe/Mn-SOD的克隆及对高低温胁迫的响应

Cloning of Cu/Zn-SOD1,Cu/Zn-SOD2 and Fe/Mn-SOD in Liposcelis bostrychophila(Psocoptera:Liposcelididae)and their response to high and low temperature stresses

【目的】揭示嗜卷书虱Liposcelis bostrychophila超氧化物歧化酶基因在响应高低温胁迫中的作用。【方法】通过RT-PCR克隆嗜卷书虱3个超氧化物歧化酶基因Cu/Zn-SOD1,Cu/Zn-SOD2和Fe/Mn-SOD cDNA,利用生物信息学方法分析其序列特征;采用RT-qPCR技术检测Cu/Zn-SOD1,Cu/Zn-SOD2和Fe/Mn-SOD在高温(42℃)和低温(4℃)胁迫下0,1和2 h时成虫中的相对表达量。【结果】克隆获得嗜卷书虱LbCu/Zn-SOD1,LbCu/Zn-SOD2和LbFe/Mn-SOD(GenBank登录号分别为OQ938782,OQ938783和OQ938784),开放阅读框(ORF)分别长465,630和636 bp,分别编码154,209和211个氨基酸,编码蛋白质相对分子量分别为15.85,22.33和23.72 kD,等电点分别为6.17,7.68和6.79;LbCu/Zn-SOD1和LbCu/Zn-SOD2分别具有1个和2个Cu/Zn超氧化物歧化酶特征,LbFe/Mn-SOD具有1个Fe/Mn超氧化物歧化酶特征。系统进化分析结果表明,昆虫Cu/Zn-SOD1,Cu/Zn-SOD2和Fe/Mn-SOD高度保守。高温42℃胁迫诱导嗜卷书虱成虫中LbCu/Zn-SOD1,LbCu/Zn-SOD2和LbFe/Mn-SOD的表达,其中LbCu/Zn-SOD1和LbCu/Zn-SOD2表达量在1和2 h时均显著高于对照;LbFe/Mn-SOD表达量在1 h时显著低于对照,而在2 h时显著高于对照。低温4℃胁迫下,与对照相比,嗜卷书虱成虫中LbCu/Zn-SOD1和LbCu/Zn-SOD2的表达量在1 h时无显著差异,而LbFe/Mn-SOD的表达量显著降低,LbCu/Zn-SOD1,LbCu/Zn-SOD2和LbFe/Mn-SOD的表达量在2 h时均显著升高。【结论】超氧化物歧化酶基因LbCu/Zn-SOD1,LbCu/Zn-SOD2和LbFe/Mn-SOD参与了嗜卷书虱对极端温度胁迫的耐受性。

【Aim】To reveal the role of the superoxide dismutase genes in Liposcelis bostrychophila in response to high and low temperature stresses.【Methods】The cDNAs of three superoxide dismutase genes Cu/Zn-SOD1,Cu/Zn-SOD2 and Fe/Mn-SOD of L.bostrychophila were cloned by RT-PCR,and their sequence characteristics were analyzed by bioinformatics methods.RT-qPCR was used to detect the relative expression levels of Cu/Zn-SOD1,Cu/Zn-SOD2 and Fe/Mn-SOD in adults at 0,1 and 2 h under high temperature(42℃)and low temperature(4℃)stresses.【Results】LbCu/Zn-SOD1,LbCu/Zn-SOD2 and LbFe/Mn-SOD(GenBank accession numbers are OQ938782,OQ938783 and OQ938784,respectively)of L.bostrychophila were cloned,with the open reading frames(ORFs)of 465,630 and 636 bp in length,encoding 154,209 and 211 amino acids with the relative molecular weights of 15.85,22.33 and 23.72 kD,and the isoelectric points of 6.17,7.68 and 6.79,respectively.LbCu/Zn-SOD1 and LbCu/Zn-SOD2 had one Cu/Zn superoxide dismutase signature and two Cu/Zn superoxide dismutase signatures,respectively.LbFe/Mn-SOD had one Fe/Mn superoxide dismutase signature.The results of phylogenetic analysis showed that Cu/Zn-SOD1,Cu/Zn-SOD2 and Fe/Mn-SOD were highly conserved in insects.The expression of LbCu/Zn-SOD1,LbCu/Zn-SOD2 and LbFe/Mn-SOD in adults of L.bostrychophila was induced by high temperature 42℃stress,and the expression levels of LbCu/Zn-SOD1 and LbCu/Zn-SOD2 in adults of L.bostrychophila were significantly higher than that of the control at 1 and 2 h.The expression level of LbFe/Mn-SOD in adults of L.bostrychophila was significantly lower than that of the control at 1 h and significantly higher than that of the control at 2 h under 42℃stress.There was no significant difference in the expression levels of LbCu/Zn-SOD1 and LbCu/Zn-SOD2 in adults of L.bostrychophila at 1 h,while that of LbFe/Mn-SOD decreased significantly at 1 h and those of LbCu/Zn-SOD1,LbCu/Zn-SOD2 and LbFe/Mn-SOD increased significantly at 2 h under 4℃stress as compared with that of the control.【Conclusion】The superoxide dismutase genes LbCu/Zn-SOD1,LbCu/Zn-SOD2 and LbFe/Mn-SOD are involved in the tolerance of L.bostrychophila to extreme temperature stress.