香蕉叶片颗粒结合性淀粉合成酶Ⅰ和可溶性淀粉合成酶Ⅲ基因的克隆与序列分析

摘要

以香蕉栽培品种“天宝蕉”(Musa spp.cv.Tianbao)的叶片为材料,采用同源克隆法结合RT-PCR和RACE法,首次从香蕉中获得颗粒结合性淀粉合成酶Ⅰ (Granule-Bound Starch SynthaseⅠ,GBSS Ⅰ)基因的cDNA全长片段和可溶性淀粉合成酶Ⅲ(Soluble Starch SynthaseⅢ,SSⅢ)基因的ORF,并分别对其核酸序列及其推导的氨基酸序列进行了生物信息学分析.香蕉叶片GBSS Ⅰ基因全长2 277 bp,编码616个氨基酸；SSⅢ基因ORF长3009bp,编码1 054个氨基酸.GBSSⅠ和SSⅢ的克隆为从分子生物学水平上研究香蕉叶片中参与淀粉合成的关键酶的表达与调控奠定重要基础.%The complete cDNA sequence of GBSS I and the ORF of SS Ⅲ were obtained from the leaves in Musa spp. cv. 'Tianbao' for the first time by the methods of homologous cloning, combined by RT-PCR and RACE. The nucleotide and deduced amino acid sequences of those two genes were analyzed by bioinformatics. The sequences had been submitted to the GenBank database. The complete cDNA of GBSS I was 2 277 bp, encoding 616 amino acids and the ORF of SSⅢ was 3009bp, encoding 1 054amino acids. The cloning of GBSS /and SSⅢ was of great importance to further studies on the expression and regulation of the key enzymes which were involved in the starch synthesis of leaves from the molecular biology level in banana.