黑皮果蔗(Badila)节间蔗糖质量分数及其关键酶活性和相关基因表达的分析
Mass Fraction of Sucrose and Activity of Key Enzymes and Related Genes Expression in Internodes of Chewing Cane (Badila)

以成熟期黑皮果蔗(Badila)的第2、5、8、12节间为材料，分析测定其节间蔗糖质量分数与相关关键酶如蔗糖磷酸合成酶(sucrose-phosphate synthase, SPS）、可溶性酸性转化酶(soluble acid invertase, SAI)、中性转化酶(neutral invertase, NI)活性，并采用RT-PCR对SPS、SAI基因在4个不同节间部位中的表达差异进行半定量分析。结果表明，成熟期黑皮果蔗蔗茎中不同节间的蔗糖、还原糖质量分数均随着节间的成熟而增加，成熟节间>未成熟节间；蛋白质质量分数则相反，为未成熟节间高于成熟节间。SPS活性与SPSⅢ基因表达则是在幼嫩茎的活性高于成熟茎；SAI活性也是幼嫩茎大于成熟茎，其基因表达差异表现不明显。NI活性以第5节间最低，其他3个节间极显著差异。
The 2nd, 5th, 8th and 12th internode of chewing cane ( Badila) was used as experimental material to assay the sucrose content and the activity of the key enzymes, i.e., sucrose-phosphate synthase (SPS), soluble acid invertase (SAI) and neutral invertase (NI) related to sucrose metabolism, and the expressions of genes was also assayed by semi-quantitative RT-PCR at mature stage. The results showed that the contents of sucrose and hexose sugars in different internodes increased with the numbers of internodes, and mature internodes > immature internodes; the soluble protein content was contrary and immature internodes > mature internodes. The activity of SPS enzyme and the expression of SPSⅢ gene in immature internodes were higher than of mature internodes; the activity of SAI enzyme as the same, but the gene expression had no difference. The activity of NI in No. 5 was lowest, and there had no difference for other 3 internodes.