托桂型茶花‘金盘荔枝’中花器官发育基因CjAG1的克隆与功能分析

Cloning and Function Analysis of CjAG1 Gene from Camellia japonica Cultivar ‘Jinpan Lizhi'

为探讨山茶重瓣花形成的机理,在山茶A和B类基因研究的基础上,通过同源基因查找分析,从山茶(Camellia japonica)重瓣品种‘金盘荔枝’(‘Jinpan Lizhi’)早期花芽中克隆了长度为1 418 bp的C类基因CjAG1全长cDNA序列(Genbank登录号JX843816),包括长度为224 bp的5′非编码区、768 bp的编码区和426 bp的3′非编码区三部分。基因编码的蛋白质包含258个氨基酸残基,属于不稳定亲水性蛋白,α-螺旋和无规则卷曲构成了其结构骨架。Real-time PCR检测结果显示,CjAG1基因在‘金盘荔枝’内轮花器官雄蕊和心皮的相对表达量高于外轮花器官萼片和花瓣,最高表达量是在花柱部位,子房、雄蕊、瓣化雄蕊和瓣化萼片的表达量居中。转拟南芥ag-1突变体后,阳性植株雄蕊数量恢复为6枚,证实了CjAG1基因具有调控雄蕊数量增加的功能。说明CjAG1基因可能对于‘金盘荔枝’重瓣花形成具有重要的调控作用。

In order to discuss the mechanism of double flower formation, a 1418 bp full-length cDNA of CjAG1 gene （JX843816） was cloned from the early flower bud of Camellia japonica ＇Jinpan Lizhi＇ by the homologous gene analysis after class A and B genes were studied, which consisting of 5＇-Untranslated region （UTR） of 224 bp, coding region of 768 bp and 3＇-UTR of 426 bp. The instable and hydrophilic protein encoded by CjAG1 gene contained 258 amino acids, and alpha-helix and random coil were the main construction. The results of Real-time PCR showed that the expression level of CjAG1 was higher in inside floral organs （stamen and carpel） than in outside ones （sepal and petal）. The highest level was present at style, and the middle one was present at ovary, stamen, petalody stamen and petalody sepal. The stamen of ag-1 Arobidopsis thaliana with transgenie CjAG1 gene reverted to 6, which indicated CjAG1 gene could add the quantity of stamen. The results indicated CjAG1 gene may have important regulation function in the process of ＇Jinpan Lizhi＇ double flower forming.