铁皮石斛CSLA基因家族的全基因组鉴定和表达分析

Genome-wide identification and expression analysis of CSLA gene family of Dendrobium catenatum

葡甘聚糖是铁皮石斛的标志性成分,它的生物合成主要由CSLA家族基因调控。为了系统评价铁皮石斛CSLA家族成员,通过从NCBI数据库下载铁皮石斛基因组数据,利用生物信息学手段进行DcCSLA基因家族成员的全基因组鉴定、系统进化、基因结构、蛋白质保守结构域和基序、启动子顺式元件、基因表达对胁迫响应的分析。结果显示铁皮石斛包含13个CSLA基因家族成员,均包含9~10个外显子;在进化关系中,CSLA被聚为5组,DcCSLA基因分布于所有分支中,其中groupⅠ的祖先基因在单双子叶植物分化之前已存在,groupⅡ~Ⅴ仅在单子叶植物存在,说明groupⅠ代表最早起源的类群;DcCSLA家族蛋白均含有标志性的CESA_CaSu_A2结构域;它们的启动子区域包含与胁迫和激素相关的顺式调控元件;胁迫处理下,低温诱导DcCSLA5的表达,抑制DcCSLA3的表达;翠雀小核菌侵染抑制DcCSLA3,4,6,8,9,10的表达;茉莉酸处理导致DcCSLA11表达量显著上调,DcCSLA2,5,7,12,13显著下调,表明DcCSLA基因广泛参与生物和非生物胁迫的应答。这些结果为进一步研究铁皮石斛CSLA基因在葡苷聚糖合成积累方面的功能奠定了基础。

Glucomannan is the key active ingredient of Dendrobium catenatum,and CSLA family is responsible for glucomannan biosynthesis.In order to systematically evaluate the CSLA family members of D.catenatum,the bioinformatics methods were performed for genome-wide identification of DcCSLA gene family members through the genomic data of D.catenatum downloaded from the NCBI database,and further analyses of their phylogenetic relationship,gene structure,protein conserved domains and motifs,promoter cis-elements and gene expression profiles in response to stresses.The results showed that D.catenatum contains 13 CSLA members,all of which contain 9-10 exons.In the evolutionary relationship,CSLA genes were clustered into 5 groups,DcCSLA genes were distributed in all branches.Among which the ancestral genes of groupI existed before the monocot-dicot divergence,and groupⅡ-Ⅴonly existed in the monocot plants,indicating that groupⅠrepresents the earliest origin group.CSLA proteins are characteristic of the signature CESA_CaSu_A2 domain.Their promoter regions contain cis elements related to stresses and hormones.Under different stress treatments,low temperature induces the expression of DcCSLA5 and inhibits the expression of DcCSLA3.Infection of Sclerotium delphinii inhibits DcCSLA3/4/6/8/9/10 expression.Under the treatment of jasmonic acid,DcCSLA11 expression was significantly up-regulated,and DcCSLA2/5/7/12/13 were significantly down-regulated.These results laid a foundation for further study on the function of DcCSLA genes in glucomannan biosynthesis and accumulation.