藜麦SPP基因家族全基因组鉴定及表达模式分析

Genome-wide Identification and Expression Mode Analysis of SPP Family Genes in Chenopodium quinoa

为明确CqSPPs基因家族的进化关系,以公开的藜麦基因组数据库为基础,鉴定出4个CqSPP基因,并进一步明确了各成员结构及其编码蛋白的理化性质、亚细胞定位、保守结构域、模体和启动子。以现有高通量转录组数据为基础,明确了各成员在藜麦不同组织中的表达水平,并采用qRT-PCR对各成员在苗期不同逆境下的表达水平进行了检测。CqSPPs分布于4个不同的染色体上,将其命名为CqSPP1~CqSPP4,其蛋白氨基酸数目在399~623之间,分子量介于45.24~70.77 kDa之间,理论等电点在5.64~6.93之间,同时表现出明显的亲水性。亚细胞定位预测显示除了藜麦SPP2蛋白预测结果为不确定外,其余蛋白主要定位在叶绿体上。蛋白保守模体分析结果显示,在该基因家族编码蛋白中预测得到10种保守模体,其中所有蛋白均含有8个排列顺序相同的模体。系统发育分析显示,植物中SPP基因家族可以分为5个组,其中CqSPP基因处于其中的2个组,并且与拟南芥SPP基因亲缘关系最近。启动子分析显示,各成员在启动子区域存在多种响应非生物胁迫的顺式转录元件。表达分析显示CqSPP1在各组织中均明显表达,而CqSPP4在各组织中表达量较低。在受到不同胁迫时,SPP基因家族的响应情况各不相同。结果表明CqSPPs有4个成员,且受多种非生物胁迫诱导表达,推测其可能在藜麦响应非生物胁迫过程中发挥了重要作用。

In order to clarify the evolutionary relationship of the CqSPP gene family,we identified four CqSPP genes based on the public quinoa genome database.The structure of CqSPPs and the physicochemical properties,subcellular localization,conserved domains,motifs and promoters of the encoded proteins were clarified.Based on the existing high-throughput transcriptome data,the expression levels of each member in different tissues of quinoa were clarified,and qRT-PCR was used to detect the expression level of each member under different stress at the seedling stage.CqSPPs are distributed on 4 different chromosomes,named CqSPP1~CqSPP4.The number of protein amino acids of CqSPPs is between 399 and 623.The molecular weight is between 45.24 and 70.77 kDa.The theoretical isoelectric point is between 5.64 and 6.93,and it shows obvious hydrophilicity.Except the uncertain results of CqSPP2 protein,the subcellular localization prediction results of other CqSPP proteins are all located on the chloroplast.The results of protein conservation motif analysis showed that 10 conserved motifs were predicted in the proteins encoded by this gene family,and all proteins contained 8 motifs with the same sequence.Phylogenetic analysis showed that the SPP gene family in plants could be divided into 5 groups.The CqSPP gene is in two of these groups and is the closest relative to the SPP gene of Arabidopsis.Promoter analysis showed that each member had a variety of cis-transcriptional elements in the promoter region that responding to abiotic stress.Expression analysis showed that CqSPP1 was significantly expressed in each tissue,while CqSPP4 was less expressed in each tissue.When subjected to different stresses,the responses of SPP gene families were different.The analysis results showed that CqSPPs had four members,and their expression was induced by a variety of abiotic stresses.It is speculated that they may play an important role in the response of quinoa to abiotic stresses.