橡胶树乳管特异表达顺式异戊烯基转移酶HbCPT7的功能研究

天然橡胶是重要的工业原料，主要来自橡胶树（Hevea brasiliensis），因其具有优越的化学和物理特性，广泛应用于生产生活中。在橡胶树的产胶细胞乳管中，天然橡胶由橡胶转移酶复合体催化合成，顺式异戊烯基转移酶（cis-prenyltransferase，CPT）是该复合体的关键组分。课题组在橡胶树基因组上鉴定到三个乳管特异表达的CPT基因，即HbCPT6、HbCPT7和HbCPT8。已有报道HbCPT6和HbCPT8参与催化橡胶生物合成，而HbCPT7的功能尚未深入研究。我们发现HbCPT7的蛋白定位与HbCPT6、HbCPT8均不相同，暗示HbCPT7可能以新的作用模式参与天然橡胶合成。本项目拟利用分子生物学与遗传学等技术，从基因表达、酶活性分析、橡胶转移酶复合体鉴定和转基因验证等方面，系统地解析HbCPT7参与天然橡胶合成的功能，为深入了解天然橡胶生物合成的分子机制提供新思路。

Natural rubber is a key and widely used industrial raw material, which mainly produced from Hevea brasiliensis. Rubber transferase complex catalyze the biosynthesis of natural rubber in laticiferous cells, cis- prenyltransferase (CPT) is an important component of rubber transferase complex. Based on the high-quality genome assembly of Hevea brasiliensis published previously by our research group, we have identified three CPT genes, HbCPT6, HbCPT7 and HbCPT8, which are specially expressed in laticifers. It has been reported that HbCPT6 and HbCPT8 involved in rubber biosynthesis, while the HbCPT7, so far, is less characterized functionally. Our primary results showed that the HbCPT7 exhibited different subcellular localization pattern from those of both HbCPT6 and HbCPT8, implying that it may have the new functional model in natural rubber biosynthesis. In this project the HbCPT7 will be further functionally characterized, using the technologies of molecular biology and genetics, by analysis of expression levels and rubber transferase activity of HbCPT7, identification of rubber transferase complex contain HbCPT7, transgenic verification of HbCPT7 in Russian dandelion plants. The results of this project providing a new insight into the molecular mechanism of natural rubber biosynthesis.