棉花纤维发育相关基因GhPRP10的克隆及其功能分析

Cloning and Functional Analysis of GhPRP10 Related to Fiber Development in Gossypium hirsutum

利用电子序列拼接结合RT-PCR技术,从12DPA(开花后天数)棉纤维中克隆到1个编码富含脯氨酸蛋白(PRPs)基因,命名为GhPRP10(登录号KP036633)。GhPRP10基因开放阅读框为684bp,编码228个氨基酸,其中脯氨酸(Pro)含量为34.6%。序列分析发现GhPRP10蛋白具有N端信号肽和富含脯氨酸区域,属于第一类PRPs。实时荧光定量PCR(RT-PCR)结果显示,GhPRP10在棉纤维组织中优势表达,在纤维发育过程中的表达量呈现先升高后降低的趋势,在18DPA纤维中表达量最高。利用Gateway技术构建植物过量表达载体,转入烟草BY-2悬浮细胞,表型观察和细胞长度测量结果显示,转GhPRP10基因细胞比野生型细胞显著增长。根据该基因的组织表达特征和转基因细胞表型分析,推测GhPRP10基因在纤维伸长和次生壁合成过程中发挥作用。

In this study,a new gene encoding proline-rich protein was isolated from 12 days post anthesis （DPA） cotton fiber, and designated as GhPRPIO. The ORF of the gene was 684bp encoding 228 amino acids,contained 34.6 % proline. The bioinformatics analysis showed that the protein encoded by this gene belonged to the first class of PRPs, which has a signal peptide in N terminal and a proline rich conserved region. The quantitative RT-PCR results showed that GhPRP10 is preferentially expressed in cotton fiber. The transcript level increased along with fiber development and reached the highest abundance at 18DPA, after which time it gradually decreased. The plant over-expression vector was constructed using Gateway technology and then transformed into tobacco suspension BY-2 cells. The phenotype observation and cell length measurement found that the transgenic cells were significantly longer than that of the wild type. Based on the expression profile of GhPRP10 and phenotype analysis of transgenic cells,it is presumed that the gene plays an important role in the process of fiber elongation and secondary wall synthesis.