一个辣椒肌醇半乳糖苷合成酶同源基因的全长cDNA克隆与低温表达分析

采用RT-PCR结合RACE技术，从低温处理的辣椒(Capsicum annuum L.)品种“苏长红”叶片中克隆得到一个肌醇半乳糖苷合成酶同源基因（GS）的cDNA序列(GenBank登录号：EF566470), 其全长1 444 bp, 推断其编码336个氨基酸。序列分析表明该基因与其他高等植物的GS基因具有较高的同源性。利用RT-PCR技术分析辣椒受低温胁迫后该基因的表达情况，发现该基因常温下在辣椒各组织中均无表达，经4 ℃或10 ℃处理6 h后在叶片中开始表达，而茎和根系中无论低温处理与否均不表达。Southern杂交结果表明辣椒基因组中还存在其他GS同源基因。

Cloning, Characterization and Expression of a Putative Galactinol Synthase Gene from Cold Stressed Pepper (Capsicum annuum L.)

Full length cDNA sequence of a putative galactinol synthase gene (GS) (Genbank locus: EF566470) was cloned from cold-stressed pepper (Capsicum annuum L. cv. 'Suchanghong') leaves using RT-PCR and rapid amplification of cDNA ends (RACE). The cDNA consists of 1 444 bp encoding a putative protein of 336 amino acids. Phylogenetic analysis revealed that this gene is high homologous to reported GS genes of other plants. RT-PCR analysis showed that the mRNAs of this gene was induced in pepper leaves after 4 ℃ or 10 ℃ cold-treatment for 6 h, but was not accumulated in cold -stressed stems and roots, no mRNA of this gene can be detected in pepper tissues under normal temperature. Southern blot analysis indicated that there may be other GS family gene copies in the pepper genome.