龙眼纤维素合成酶基因家族成员鉴定及表达模式

Identification and expression patterns of the cellulose synthase gene family in Dimocarpus longan Lour.

为探究龙眼纤维素合成酶(cellulose synthase,CESA)家族的生物学功能,采用生物信息学分析方法进行龙眼CESA(DlCESA)家族成员鉴定、蛋白特性和保守基序分析、分子进化树分析、FPKM值分析,并利用qRT-PCR技术分析DlCESA基因的表达模式.结果表明,DlCESA家族包含9个基因成员,家族成员内含子数量8-13个不等,且蛋白理化性质相近,均包含15个保守的motif;系统进化树分析表明DlCESA分布于6个分支上;顺式作用元件分析表明DlCESA家族启动子序列含有众多植物激素响应、厌氧响应等元件;FPKM值分析表明DlCESA家族在NEC阶段高表达,大部分成员在体胚发生过程中呈现下调表达趋势;除DlCESA7-2外其余DlCESA基因在龙眼不同组织部位都有所表达.qRTPCR分析表明,4个DlCESA基因在非胚性阶段表达量较高;DlCESA成员可被ABA和MeJA下调表达.本研究表明DlCESA可能参与龙眼生殖生长和体胚发生进程,并响应逆境胁迫.(图9表2参47)

To clarify the biological function of the cellulose synthase(DlCESA) gene family in longan(Dimocarpus longan Lour.), the gene structure, protein characteristics, conserved motifs, cis-acting elements and promoter, phylogenetic tree, and the FPKM values of DlCESA gene family were analyzed by the bioinformatics methods, and qRT-PCR was further used to detect the expression patterns of DlCESA. The results showed that the DlCESA gene family contained 9 members, and their introns ranged from 8 to 13. The physicochemical properties of the different DlCESA proteins were similar, and 15 conserved motifs were found. Phylogenetic analysis showed that the DlCESA were clustered into six groups;cis-acting elements of promoter sequences analysis showed DlCESA contained many plant hormone cis-acting elements and anaerobic elements. The FPKM values showed that DlCESA genes were highly expressed in non-embryogenic cultures(NEC) and down-regulated in the process of early somatic embryogenesis, and DlCESA genes were expressed in a range of tissues except DlCESA7-2. Meanwhile, qRT-PCR analysis showed that four DlCESA genes showed higher expression levels in the NEC stage, and ABA and MeJA down-regulated the expression of DlCESA genes. This study showed that DlCESA genes might be involved in reproductive growth, the somatic embryogenesis of longan, and abiotic stress response.