茶树中葡萄糖-6-磷酸脱氢酶基因（CsG6PDHs）的克隆与表达分析

葡萄糖-6-磷酸脱氢酶（Glucose-6-phosphate dehydrogenase,G6PDH,EC1.1.1.49）是戊糖磷酸途径中的关键限速酶,在植物逆境胁迫响应和生长发育中具有重要作用。然而,目前有关G6PDH在茶树中的研究尚处空白。在茶树中克隆到3个CsG6PDHs基因,分别命名为CsG6PDH1（MW025829）、CsG6PDH2（MW025830）、CsG6PDH4（MW025831）。聚合进化树结果显示,CsG6PDH1和CsG6PDH4均为质体型蛋白,而CsG6PDH2为胞质型蛋白。表达分析发现,CsG6PDHs在不同组织中均有表达;低温或炭疽菌侵染条件下,CsG6PDH1和CsG6PDH4均被抑制表达;冷驯化期间,CsG6PDH2和CsG6PDH4在不同品种中均上调表达;此外,CsG6PDHs在茶芽休眠和萌发过程中均不同程度上调表达。以上结果表明,CsG6PDHs在茶树生长发育和逆境胁迫响应过程中发挥着重要作用,这为后续深入研究G6PDH在茶树中的功能奠定了理论基础。

Identification and Expression Analysis of Glucose-6-hosphate Dehydrogenase Gene (CsG6PDHs) in Camellia sinensis

As a key rate-limiting enzyme in pentose phosphate pathway, glucose-6-phosphate dehydrogenase (G6PDH, EC1.1.1.49) plays an important role in plant growth and development, and also in responding to environmental stresses. However, the function of G6PDH in tea plants has not yet been reported. In our study, 3 G6PDH genes were cloned from tea plant, named as CsG6PDH1 (MW025829), CsG6PDH2 (MW025830) and CsG6PDH4 (MW025831), respectively. Phylogenetic analysis shows that CsG6PDH1 and CsG6PDH4 belong to plastid protein, while CsG6PDH2 belongs to cytoplasmic protein. Quantitative analysis shows that the expressions of CsG6PDHs varied in different tissues. Under cold or Colletotrichum infection treatments, the time course expressions of both CsG6PDH1 and CsG6PDH4 were gradually reduced. Besides, both CsG6PDH1 and CsG6PDH4 were induced by cold acclimation in different tea cultivars. In addition, the expressions of CsG6PDHs were up-regulated during bud dormancy and flush periods. Consequently, our results implicate that CsG6PDHs are widely participated in tea plant growth and development, and also involved in responding to abiotic and biotic stresses. This study provided a theoretical basis for in-depth study of the function of CsG6PDHs in tea plants.