茶树新梢中纤维素酶活性及相关基因表达差异分析

Differences Analysis of Cellulase Activity and Its Related Gene Expression in Shoots of Camellia sinensis

摘要:

为了解茶树新梢中纤维素酶的生理特征，对3个茶树（Camellia sinensis）品种新梢中纤维素酶活性的变化和相关基因的表达进行了研究。结果表明，3个茶树品种新梢中的纤维素酶活性差异显著，‘平阳特早’和‘凫早2号’随着叶片成熟度增加，内切葡聚糖酶和外切葡聚糖酶活性升高，‘舒茶早’则相反。β-葡萄糖苷酶活性在3个茶树品种都是在一芽三叶时期最低，且幼嫩部位的酶活性高于成熟部位，但其酶活性高于外切葡聚糖酶活性。半定量RT-PCR结果表明，5个纤维素酶相关基因在3个茶树品种新梢中均有表达，有2个β-葡萄糖苷酶同源基因的表达量差异显著。因此，纤维素酶可能在茶叶的品质形成中起作用。

Abstract:

In order to understand the characteristics of cellulase in shoots of Camellia sinensis, the changes in cellulase activity and related gene expressions in three cultivars of C. sinensis were studied. The results showed that the cellulase activity in the three cultivars had significant difference. The activities of the endo-glucanase and exo-glucanase in ‘Pingyang Tezao’ and ‘Fuzao No. 2’ increased with leaf maturity, which was contrary to the ‘Shuchazao’. The β-glucosidase activity in the three cultivars was the lowest at stage of three leaves with a bud, and its activity in young parts was higher than that in maturity parts in shoots. Otherwise, the activity of β-glucosidase in tea shoots was higher than that of exo-glucanase. The expresions of five cellulase-related genes could be detected in shoots of three cultivars by semi-quantitative PCR, in which the expression of two homologous genes had significant difference. Therefore, the glucanase would play a role in quality formation of tea.