茶树DELLA基因家族的鉴定及表达分析

利用生物信息学方法，从茶树（Camellia sinensis（L.）O.Ktze.）全基因组数据库中分析获得DELLA蛋白的家族成员，并对它们的系统进化关系、蛋白序列特征、基因表达特异性及其与茶树次生代谢物的相关性进行分析。结果显示：茶树基因组中共有5个DELLA基因，分别为：TEA009882（CsGAI）、TEA022818（CsRGA1）、TEA010112（CsRGL1）、TEA008736（CsRGL2）和TEA020933（CsRGL3）；其编码的氨基酸数量在525~594之间，均定位于细胞核。该蛋白的二级和三级结构分析结果表明，茶树DELLA蛋白结构中含有大量的α螺旋及少量β转角结构。蛋白保守结构域分析结果显示该蛋白与拟南芥（Arabidopsis thaliana（L.）Heynh.）具有高度的同源性，均具有GRAS、DELLA等保守结构域。基因的表达特异性分析结果表明，在茶树不同组织部位中，TEA009882、TEA022818和TEA010112基因的表达量均较高，而TEA020933和TEA008736的表达量在各组织中均较低；茶树DELLA基因的表达受到干旱、NaCl、低温及茉莉酸甲酯等非生物逆境胁迫的调控，且其表达量与茶树次生代谢物的积累间存在相关性。推测茶树DELLA基因广泛参与了茶树生长发育及非生物逆境胁迫的响应，以及对次生代谢物生物合成过程的调控。

Identification and expression analysis of the DELLA gene family in Camellia sinensis (L.) O. Ktze.

Using bioinformatics methods, DELLA protein family members were analyzed from Camellia sinensis (L.) O. Ktze. genome-wide database, and their phylogenetic relationships, protein sequence characteristics, gene expression specificity, and correlation with secondary metabolites of C. sinensis were analyzed. Results identified five DELLA genes in C. sinensis: i.e., TEA009882 (CsGAI), TEA022818(CsRGA1), TEA010112(CsRGL1), TEA008736(CsRGL2), and TEA020933(CsRGL3). The number of amino acids encoded by DELLA genes ranged from 525-594 aa, all of which were located in the nucleus. Results also showed a large number of α helices and several β corners in the secondary and tertiary structures of the DELLA proteins in C. sinensis. Based on conservative domain analysis, the DELLA proteins showed high conservation in C. sinensis and Arabidopsis thaliana, with GRAS, DELLA, and other conserved motifs. Gene expression specificity showed that the expression levels of the TEA009882, TEA022818, and TEA010112 genes were high in different tissues of C. sinensis, whereas the expression levels of the TEA020933 and TEA008736 genes were very low. The expression of DELLA protein genes was regulated by abiotic stresses, such as drought, NaCl, low temperature, and methyl jasmonate (MeJA), and gene expression was correlated with the accumulation of secondary metabolites. It is speculated that DELLA genes in C. sinensis plants are widely involved in morphogenesis, abiotic stress responses, and regulation of secondary metabolite biosynthesis in C. sinensis.