蓖麻CNGC基因家族鉴定与冷胁迫下的表达模式分析

Identification of RcCNGC Gene Family in Castor Bean(Ricinus communis)and Analysis of Expression Pattern under Cold Stress

环核苷酸门控通道蛋白(cyclic nucleotide-gated channel proteins,CNGCs)是介导低价阳离子转运的重要蛋白,在植物信号传递、生长发育与非生物胁迫响应等方面发挥重要作用。本研究利用序列比对法在蓖麻基因组水平进行CNGC家族成员鉴定;利用生物信息学手段对蓖麻CNGC家族成员的基因结构、保守基序、特征结构域、聚类方式、顺式作用元件及染色体定位信息进行分析。研究成功鉴定到17个蓖麻CNGC基因家族成员,定位于16个未完整拼接的染色体片段上;除RcCNGC13外,其他蛋白序列均包含高度保守的环核苷酸结合结构域CNBD,但RcCNGC4RcCNGC6RcCNGC13RcCNGC14均存在明显的基序缺失;部分RcCNGCs启动子区均含有MYB、MYC与ABRE、ARE元件,推测其响应逆境胁迫。聚类分析将蓖麻CNGC成员分为Ⅰ、Ⅱ、Ⅲ、Ⅳ组,推测不同类型CNGC蛋白存在功能差异。转录组数据分析发现仅有RcCNGC14受冷胁迫显著上调表达,暗示该基因参与调控蓖麻的冷适应性。本研究首次在蓖麻全基因组水平对CNGC基因家族进行鉴定,并分析其冷胁迫下的表达模式,为进一步创制蓖麻抗冷新种质提供重要的候选基因。

Cyclic nucleotide-gated channel proteins(CNGCs) are important proteins that mediate the transport of low-valent cations and play an important role in plant signal transmission,growth and development,and response to abiotic stresses.In this study,the CNGC family genes were identified by sequence alignment at the genome level of Ricinus communis.The gene structure,conserved motifs and domains,clustering patterns,cis-regulatory elements and chromosomal location of Ricinus communis CNGC were analyzed by bioinformatics methods.17 Ricinus communis CNGC(RcCNGC) gene family were successfully identified and located on 16 incomplete spliced chromosome segments.All the protein sequences except RcCNGC13 contained highly conserved cyclic nucleotide binding domain CNBD;However,RcCNGC4RcCNGC6RcCNGC13RcCNGC14 has obvious motif deletions;partial RcCNGCs contain MYB,MYC,ABRE and ARE elements,which indicated that RcCNGCs were involved in stress response.The cluster analysis preliminarily classified RcCNGC into groups Ⅰ,Ⅱ,Ⅲ,and Ⅳ,and speculated that different types of RcCNGC have functional differences.Based on transcriptome(RNA-seq) data,the study found that only the expression of RcCNGC14 was up-regulated after cold stress,which indicated it may be involved in regulating cold adaptation of Ricinus communis.This study firstly identified RcCNGCs at the whole genome level of Ricinus communis and analyzed gene expression under cold stress,which will provide important candidate genes for further creation of new cold tolerant castor cultivar by genetic engineering.