小麦衰老相关基因TaSAG39的生物信息学及表达模式分析  

Bioinformatics and Expression Pattern Analysis of Senescence-associated Gene TaSAG39 in Wheat

作　　者：孙丽丽 晋秀娟 赵锴 Md Ashraful Islam 卢娟 王曙光[1,2] 孙黛珍 SUN Lili;JIN Xiujuan;ZHAO Kai;Md Ashraful Islam;LU Juan;WANG Shuguang;SUN Daizhen(College of Agriculture,Shanxi Agricultural University,Taigu 030801,China;The Provincial and Ministerial Cooperative National Key Laboratory of Organic Dry Farming(in Preparation),Taiyuan 030031,China)

机构地区：[1]山西农业大学农学院,山西太谷030801 [2]省部共建有机旱作农业国家重点实验室(筹),山西太原030031

出　　处：《华北农学报》2022年第2期18-27,共10页Acta Agriculturae Boreali-Sinica

基　　金：山西农业大学省部共建有机旱作农业国家重点实验室自主研发项目(202002-2)。

摘　　要：半胱氨酸蛋白酶是蛋白质降解过程中的一类水解酶,参与植物的衰老与成熟,在植物生长发育过程中发挥重要作用。基于前期得到的小麦衰老阶段转录组数据中筛选到一个衰老特异的半胱氨酸蛋白酶(SAG39),为了研究TaSAG39基因在小麦衰老过程中发挥的作用,采用生物信息学分析方法和实时荧光定量(qRT-PCR)技术对TaSAG39的基因结构和表达模式进行分析。结果表明,其氨基酸序列与小麦祖先种节节麦、野生二粒小麦以及硬粒小麦亲缘关系最近,含有木瓜蛋白酶亚家族特有的活性位点Cys-His-Asn以及EFNIN结构。TaSAG39-5A、TaSAG39-5B、TaSAG39-5D基因组全长分别为1455,1435,1439 bp,编码序列长分别为1041,1050,1038 bp,均含2个外显子和1个内含子;其编码的蛋白分别由346,349,345个氨基酸组成,分子质量约37 ku,等电点5.53~5.67,为稳定的带负电的亲水性蛋白;主要构成元件为无规则卷曲和α-螺旋,在蛋白质N段含有信号肽,具有保守的Inhibitor_I29和Peptidase_C1结构域,含有35~37个磷酸化位点,其中以丝氨酸磷酸化位点和苏氨酸磷酸化位点为主。TaSAG39蛋白可能与半胱氨酸蛋白酶抑制剂以及14-3-3蛋白互作,该基因启动子中含有脱落酸、茉莉酸甲酯、生长素、光、干旱、低温以及胁迫响应等有关的顺式作用元件。qRT-PCR结果证实,TaSAG39基因受自然衰老、黑暗、干旱、茉莉酸甲酯、高温、生长素诱导表达,在自然衰老过程中基因的诱导表达最为显著。Cysteine protease,a kind of hydrolase in the process of protein degradation,participates in the senescence and maturation of plants and plays an important role in the growth and development of plants.In this study,a senesence-specific cysteine protease(SAG39)was screened from the previously obtained transcriptome data of wheat at senescence stage.In order to study the role of TaSAG39 gene in wheat at senescence,the gene structure and expression pattern of TaSAG39 were analyzed by bioinformatics analysis and Real-time fluorescence quantitative(qRT-PCR)technology.The results showed that the amino acid sequence encoded by the cysteine protease gene SAG39 had the closest relationship with the ancestral species of wheat,such as Aegilops tauschii,Triticum dicoccoides and Triticum durum,and it included the unique active site Cys-His-Asn and EFNIN structures of the papain sub-family.The full-length genomes of TaSAG39-5A,TaSAG39-5B and TaSAG39-5D were 1455,1435,1439 bp,respectively,and the length of the coding sequence was 1041,1050,1038 bp,respectively,with each containing two exons and one intron.The TaSAG39s proteins consisted of 346,349,345 amino acids.With relative molecular weight of about 37 ku and isoelectric point of 5.53—5.67,these proteins were stable negatively charged hydrophilic proteins.Its main components were random coils andα-helix,and there were signal peptides in the N segment of the protein.It had the conserved Inhibittor_I29 and Petidase_C1 domains,and contained 35—37 phosphorylation sites,mainly serine and threonine phosphorylation sites.TaSAG39 protein may interact with cysteine protease inhibitors and 14-3-3 protein.The promoter contained cis-acting elements relative to abscisic acid,methyl jasmonate,auxin,light,drought,low temperature and stress response.The results of qRT-PCR confirmed that gene TaSAG39 was induced to express by natural aging,darkness,drought,methyl jasmonate,high temperature and auxin,among which natural aging was the most significant.

关 键 词：小麦 TaSAG39 半胱氨酸蛋白酶 生物信息学分析 表达模式 

分 类 号：S512.1[农业科学—作物学] Q78[生物学—分子生物学]