高粱耐逆基因SbALDH7的克隆与表达分析

Isolation and Expressing Analysis of A Stress Tolerance Gene SbALDH7 in Sorghum bicolor

旨在研究高粱(Sorghum bicolor)中的醛脱氢酶基因SbALDH7的序列信息和表达分析。通过PCR和RT-PCR方法,从高粱中克隆SbALDH7基因及其cDNA全长序列。通过网络软件,聚类分析SbALDH7的序列特征,利用半定量RT-PCR,研究其在不同组织和胁迫条件下的表达谱。结果表明:SbALDH7基因含13个内含子,共编码509个氨基酸,其编码的氨基酸序列具有典型的ALDH7结构域特征。SbALDH7的表达受到PEG、Nacl、ABA和低温等胁迫环境诱导上调。组织特异性表达分析显示,在PEG渗透胁迫环境下,SbALDH7在茎、叶中的表达量显著高于根中的表达量。抗旱性有显著差异的6个高粱品种的SbALDH7蛋白序列无差异,但高粱品种的苗期抗性与SbALDH7的表达量间存在显著的正相关,表明SbALDH7的表达对高粱的抗旱性可能起着重要的作用。SbALDH7具备醛脱氢酶家族蛋白典型结构特征,在高粱抗逆过程中起重要作用,可作为提高高粱抗旱耐盐的靶基因应用于作物遗传改良。

The sequence features and expression patterns of SbALDH7 were studied in Sorghum hicolor. The eDNA of SbALDH7 was cloned by RT-PCR. The structure features was analyzed by bioinformatics software. The expression patterns of the gene were investigated using Semi-quantitive RT-PCR in different tissues under different stress. The result showed that SbALDH7 included 13 introns and encoded a protein sequence with 509 amino acids. The protein deduced from SbALDH7 possesses typical characteristics of members of the ALDH7 protein family. Transcript levels of the SbALDH7 genes were upregulated by PEG, NaC1, ABA and 4~C. In PEG osmotic stress, transcript levels of the SbALDH7 gene were higher in leaf and culm than in root. There was no difference in SbALDH7 protein sequences of six sorghum varieties, which had remarkably different drought tolerance. However, there was remarkable positive correlation between seedling drought resistance of varieties and transcript levels of SbALDH7. The results showed expression of SbALDH7 was important for drought tolerance of Sorghum bieolor. SbALDH7 had typical structure features of ALDH protein family, and it played an important role during the process of stress response. SbALDH7 could be used as a target gene for crop genetic improvement.