棉花GhPME1和GhPME2基因的克隆及表达分析

本研究旨在对棉花来源的果胶甲酯酶基因进行克隆和功能分析。通过RACE技术克隆了2个棉花果胶甲酯酶基因的cDNA,命名为GhPME1和GhPME2。序列分析发现:GhPME1和GhPME2的最大开放阅读框分别为1 704和1 752bp,分别编码含有567和582个氨基酸的蛋白质。蛋白质结构预测显示这2个蛋白结构相似,包含PMEI和Pectinesterase结构域。RT-PCR和实时荧光定量PCR结果显示在陆地棉的纤维发育过程中,GhPME1和GhPME2的表达峰值分别在9和4DPA(开花后天数),然后依次降低。而在海岛棉纤维中,这2个基因的表达均呈现逐渐上升的趋势,表达峰值分别出现在开花后24和29DPA。GhPME1和GhPME2在海岛棉和陆地棉棉纤维中的表达差异初步证明该基因家族的功能可能与棉纤维品质相关。

Cloning and expression analysis of GhPME1 and GhPME2 in cotton

This paper aimed at cloning two pectin methylesterase genes-GhPME1 and GhPME2,in order to provide assistance to study the role of the pectin metabolism in the development of cotton fibers.The cDNA of GhPME1 and GhPME2 was amplified by RACE and the characteristics were analyzed by the bioinformatics software.The lengths of the nucleotide sequence for the open-reading frame of GhPME1 and GhPME2 were 1 704 and 1 752 bp respectively,encoding a polypeptide of 567 and 582 amino acids.RT-PCR and real time-PCR analysis showed that in the upland cotton fibers,the maximum expression level of GhPME1 and GhPME2 was at 9 DPA (Day Post Anthesis) and 4 DPA,falling down after that.However,in Sea Island cotton fibers development,GhPME1 and GhPME2 showed a gradual upward trend,expression peak was in 29 and 24 DPA.The difference of expression patterns of GhPME1 and GhPME2 in cotton fibers from different genotype of cotton,providing a preliminary proof for the difference of cotton fiber quality which relates to genotype.