Isolation of B function CjDEF-1 gene involved in floral development in Camellia japonica hongshibaxueshi and its expression analysis | 重瓣山茶红十八学士花发育B功能基因CjDEF-1的分离与表达分析

Chinese. 为研究B功能基因在山茶重瓣花形成中作用，用同源克隆的方法从红十八学士(Camellia japonica Hongshibaxueshi)花芽cDNA中克隆到DEFICIENS(DEF)基因同源序列片段，用RACE(rapid amplification of cDNA end)技术获得该基因cDNA全长，命名为CjDEF-1(GenBank登录号为HM773024.1)。通过氨基酸序列比对分析了一些单瓣、重瓣植物DEF同源基因差别，并采用Real-time PCR技术研究CjDEF-1基因在红十八学士中的时、空表达特点。结果显示，红十八学士CjDEF-1基因cDNA全长1 013 bp，包含一个完整开放阅读框，编码226个氨基酸。序列分析表明，红十八学士与近缘雪山茶(Camellia japonica subsp. rusticana)至少有4个编码氨基酸不同。在红十八学士不同发育时期中，CjDEF-1基因在小花苞表达量最高，中等花苞表达量最低，在开花期表达量又升高；在花不同组织中的表达情况从高到低排列为：中心花瓣外轮花瓣中间花瓣萼片苞片，这与同源CjDEF基因在单瓣雪山茶中表达情况不同。从这些研究的差异表明，CjDEF-1基因可能在山茶重瓣花形成中起作用。

English. To investigate the mechanism of B function genes for double flower development in Camellia japonica, CjDEF-1 was cloned and its expression characteristic was analyzed. CjDEF-1 fragment was cloned from C. japonica Hongshibaxueshi flower buds based on homologous sequence from online blast results, and the full length of CjDEF-1 cDNA was amplified by RACE method (GenBank Accession No.HM773024.1). The spatialtemporal expression pattern of CjDEF-1 gene was studied by Real-time PCR. The results exhibited that CjDEF-1 cDNA sequence length was 1 013 bp and included an completed ORF (open reading frame) and encoded 226 amino acids. The sequence analysis showed that there were four encoding amino acid differences between C. japonica subsp. rusticana and C. japonica Hongshibaxueshi. The highest expression was in small buds, the lowest was in middle buds, while the expression went up at flower stage. The expression results from highest to lowest at different flower tissue were central petals, outside petals, middle petals, sepals and bracts. These differences with single flower showed that CjDEF-1 gene may be involved in formal double thigmomorphogenesis in Camellia.