茶树鸟氨酸转氨酶基因Csδ-OAT的克隆与表达分析

根据已知鸟氨酸转氨酶（δ-OAT）的保守序列设计简并引物，并利用RT-PCR和RACE技术从‘迎霜’茶树中克隆获得鸟氨酸转氨酶基因，命名为Csδ-OAT，其GenBank登录号为KJ641844。该基因cDNA全长为1 865 bp，编码473个氨基酸，理论等电点为7.19，推测分子量为52.3 kD。序列比对分析结果表明，Csδ-OAT主要功能域保守性较高，存在典型的PLP结合位点；系统进化树分析显示，Csδ-OAT的进化符合传统的生物学分类，与其他双子叶植物具有同一起源。qRT-PCR分析结果表明，Csδ-OAT基因的表达存在明显的组织特异性，在花中表达最高，其次是叶片，而在其他组织器官中表达较低。此外，Csδ-OAT基因受高盐、低温、干旱、ABA和氧化胁迫处理的诱导，表明其参与了茶树体内各种非生物胁迫响应的过程。

Cloning and Expression Analysis of Ornithine-δ-aminotransferase Gene Csδ-OAT in Camellia sinensis

Degenerate primers were designed according to the known conserved regions of Ornithine- δ-aminotransferase gene（δ-OAT），and the complete cDNA sequence of δ-OAT was firstly cloned from Camellia sinensis using RT-PCR and RACE technologies. The cDNA was termed Csδ-OAT（GenBank accession KJ641844）and its full-length was 1 865 bp encoding a protein of 473 amino acids. The molecular weight of Csδ-OAT was 52.3 kD and theoretical isoelectric point was 7.19. The BLAST results showed that the functional domain of Csδ-OAT is highly conserved with a typical PLP binding site. Phylogenetic analysis of plant δ-OAT reveals that the evolution of Csδ-OAT corresponds with traditional biological classification. QRT-PCR analysis results showed that the expression of Csδ-OAT has obvious tissue specificity，and it was higher in flower，followed by leaves，but lower in other tissues. Moreover，we found that the expression of Csδ-OAT is induced by different abiotic stresses，including low- temperature，high salinity，ABA，drought and oxidative stresses，implying that Csδ-OAT is involved in responding to abiotic stress in plants.