黄瓜抗旱相关基因CsMYB94的克隆与表达分析

Cloning and Expression Analysis of Drought-Related Gene CsMYB94 in Cucumber

干旱胁迫是黄瓜质量和产量最严重威胁之一。为了更好地了解黄瓜响应水分胁迫的分子机理,从前期工作中得到一个与干旱有关且显著上调表达的差异表达基因CsaV3_3G039670(log_(2)FC=1.10),其在拟南芥中同源基因AtMYB94通过调节植株表皮蜡质的含量来提高抗旱性,因此命名为CsMYB94。CsMYB94基因CDS序列全长为885 bp,编码294个氨基酸。通过对蛋白结构域分析,CDS序列中含有2个DNA-结合结构域,属于R2R3类型的MYB转录因子。蛋白分析发现,CsMYB94蛋白分子式为C_(1426)H_(2242)N_(404)O_(454)S_(11);预期分子量为3.27 ku;理论等电点为6.53;为疏水性蛋白质,且为不稳定蛋白。通过亚细胞定位软件分析发现,CsMYB94蛋白被定位在细胞核。通过构建系统进化树分析表明,黄瓜CsMYB94与白藻中MYB94亲缘关系最近,与南瓜、苦瓜和甜瓜中的MYB94亲缘关系较近。通过qRT-PCR分析结果表明,CsMYB94在黄瓜叶片中表达量最高,而在雄花、卷须和茎中的表达量相对较低。因此,推测CsMYB94也是通过调节黄瓜蜡质含量来响应干旱胁迫,具体调控路径还需进一步研究。

Drought stress is one of the most serious threats to cucumber quality and yield.In order to better understand the molecular mechanism of cucumber′s response to water stress,this experiment obtained a differentially expressed gene CsaV3_3G039670(log2FC=1.10)related to drought and significantly up-regulated expression from the previous work.Its homologous gene AtMYB94 was passed in Arabidopsis regulating the epidermal wax content of the plant to improve drought resistance,it was named CsMYB94.The CDS sequence of CsMYB94 gene was 885 bp in length and encoded 294 amino acids.By analyzing the protein domain,the CDS sequence contained two DNA-binding domains,which were R2R3 type MYB transcription factors.Protein analysis found that the molecular formula of CsMYB94 protein was C_(1426)H_(2242)N_(404)O_(454)S_(11);the expected molecular weight was 3.27 ku;the theoretical isoelectric point was 6.53;it was a hydrophobic protein and an unstable protein.Analysis by subcellular localization software revealed that CsMYB94 protein was localized in the nucleus.The phylogenetic tree analysis showed that CsMYB94 in cucumber had the closest relationship with MYB94 in white algae and closer to MYB94 in pumpkin,bitter gourd and melon.The results of qRT-PCR analysis showed that CsMYB94 had the highest expression in cucumber leaves,but relatively low expression in male flowers,tendrils and stems.Therefore,it is speculated that CsMYB94 also responds to drought stress by regulating the wax content of cucumber,and the specific regulation path needs further study.