水稻CPR5基因参与氧化胁迫响应

Involvement of Rice CPR5 in Response to Oxidative Stress

摘要:

为探讨水稻(Oryza sativa L.)中CPR5 基因的功能,以其cDNA 文库为基础进行序列比对,并将1 个同源性较高的序列命名为OsCPR5.生物信息学分析表明,OsCPR5 的开放阅读框长度为1551 bp,编码516 个氨基酸.软件预测该编码蛋白可能是1 个具有5 个跨膜区的膜蛋白和核定位蛋白.组织表达和亚细胞定位分析表明,OsCPR5 在根中的表达水平较高,且广泛分布在细胞膜、细胞质和细胞核上.逆境胁迫分析实验表明,植物激素脱落酸(Abscisic acid, ABA)、过氧化氢(Hydrogen peroxide,H₂O₂)、氯化钠(NaCl)、甲基紫精(Methyl viologen, MV)等环境胁迫可诱导OsCPR5 的上调表达,其中氧化胁迫相关的MV 和H₂O₂ 处理效果最为明显.拟南芥(Arabidopsis thaliana)转基因株系atcpr5/OsCPR5 在浓度为0.5 μmol L^-1、 1.0 μmol L^-1 的MV以及6 mmol L^-1、 8 mmol L^-1 的H₂O₂ 处理下,种子萌发率明显高于atcpr5 突变体.这揭示了OsCPR5 基因在植物抗氧化胁迫响应中具有一定的作用.

Abstract:

In order to understand the function of CPR5 in rice (Oryza sativa L.), a homologous sequence, named as OsCPR5, was cloned from rice full-length cDNA library by BLAST. Bioinformatics analysis showed that the length of ORF in OsCPR5 was 1551 bp, encoding 516 amino acids. The OsCPR5 protein contained five transmembrane regions at the carboxy terminus, which also existed in AtCPR5. The expression of OsCPR5 was high in roots. The subcellular localization showed that OsCPR5 distributed widely in cell membrane, cytoplasm, and nucleus. The expression of OsCPR5 in rice was up-regulated by different environment stresses, including exogenous abscisic acid (ABA), NaCl, especially methyl viologen (MV) and hydrogen peroxide (H₂O₂). When transgenic lines atcpr5/OsCPR5 of Arabidopsis thaliana were treated with methyl viologen (0.5 μmol L^-1, 1.0 μmol L^-1) and hydrogen peroxide (6 mmol L^-1, 8 mmol L^-1), the seed germination rates were higher than that of atcpr5 mutant. Therefore, it was suggested that OsCPR5 played a role in response to oxidative stress.