橡胶草SRPP/REF家族基因的鉴定及表达分析  

Genome-wide identification and expressional analysis of SRPP/REF gene family in Taraxacum kok-saghyz

作　　者：黄俊 江羽宸 张云川 闫洁[1] HUANG Jun;JIANG Yuchen;ZHANG Yunchuan;YAN Jie(College of Life Sciences,Shihezi University,Shihezi,Xinjiang 832003,China)

机构地区：[1]石河子大学生命科学学院,新疆石河子832003

出　　处：《植物生理学报》2020年第7期1541-1552,共12页Plant Physiology Journal

基　　金：国家自然科学基金项目(31860070)。

摘　　要：橡胶草(Taraxacum kok-saghyz)是研究天然橡胶生物合成的理想模式植物,小橡胶粒子蛋白/橡胶延伸因子(SRPP/REF)家族在天然橡胶合成中扮演重要角色。本研究开展对橡胶草TkSRPP/REF家族的基因鉴定、生物信息学分析及响应茉莉酸甲酯的表达分析,从橡胶草全基因组中识别到10个SRPP/REF家族基因,包含9个SRPP基因(TkSRPP1~9)和1个REF基因(TkREF1),理化性质分析发现大部分TkSRPP/REF蛋白等电点(4.6~8.7)小于6,蛋白分子量为5.6~44.6 kDa, SRPP亚家族蛋白亲水系数均小于零, REF1略大于零。亚细胞定位和跨膜结构域分析表明TkSRPP/REF均定位在细胞质中, REF1蛋白具有跨膜结构域,而SRPP亚家族蛋白均无跨膜结构域。与拟南芥、橡胶树和莴苣的SRPP/REF蛋白一起构建系统发育树共分为5个聚类组(I^V), TkSRPP/REF家族分布在其中4个聚类组(II^V),大部分与莴苣家族类似主要分布在III和IV组,而仅少数与橡胶树和拟南芥的家族成员在同一聚类组,表明橡胶草与莴苣SRPP/REF蛋白有更近的亲缘关系。TkSRPP/REF基因中有9个具有3个外显子,1个(SRPP8)含有2个外显子。TkSRPP/REF家族蛋白共有6个motif(1~6), REF亚家族只有2个motif2,属于REF保守结构域,不同聚类组上的TkSRPP亚家族蛋白的motif数量存在差异。TkSRPP/REF家族基因的启动子上具有多个激素和非生物胁迫响应元件。克隆获得8个TkSRPP/REF基因,转录组数据分析表明茉莉酸甲酯能够诱导TkSRPP3-4和TkREF1基因上调表达。qRT-PCR分析显示,茉莉酸甲酯处理6和24 h后TkREF1基因的表达水平分别下降0.5倍和上调1.5倍,而TkSRPP4基因的表达水平分别上升4.3和8.9倍。上述结果为深入研究TkSRPP/REF基因家族的功能与茉莉酸调控橡胶合成的机制提供了参考。Taraxacum kok-saghyz(Tk) is a model plant for studying rubber biosynthesis. The small rubber particle protein(SRPP) and rubber elongation factor(REF) family plays an important role in the synthesis of natural rubber. In this study, genome-wide gene probing, bioinformatics analysis and methyl jasmonate-induced expression analysis were carried out in the TkSRPP/REF family. Ten SRPP/REF genes were identified in the Tk genome, including nine SRPP genes(TkSRPP1-9) and one REF gene(TkREF1). Most proteins were predicted to have an isoelectric point(4.6-8.7) of less than 6, and a molecular weight of 5.6 kDa to 44.6 kDa. The hydrophilic coefficients of TkSRPP subfamily proteins were predicted to be less than zero, but that of TkREF1 was slightly greater than zero. All TkSRPP/REF family proteins were predicted to have a cytoplasmic location. TkREF1 protein predicted to have transmembrane domains, but all TkSRPP subfamily proteins lack transmembrane domains. The phylogenetic tree of SRPP/REF family proteins among Tk, Arabidopisis thaliana, Lactuca sativa and Hevea brasiliensis revealed five distinct subgroups(I-V). TkSRPP/REF family proteins were distributed in four of the five subgroups, with most in the subgroups of III and IV similar to L. sativa. In contrast, only few of SRPP/REF proteins from H. brasiliensis and A. thaliana were in the subgroup of III and IV. Gene structure analysis showed that nine TkSRPP/REF genes had three exons whereas TkSRPP8 had two exons. TkSRPP/REF family proteins were predicted to have a total of six motifs(1 to 6), but the TkREF1 protein had only two motifs(2) that belong to the REF domain. In comparison, the SRPP subfamily proteins had a diverse modes of motif distribution. Promoters of the TkSRPP/REF gene family were predicted to harbor multiple hormone 5 and abiotic stress-responsive cis-elements. The cDNAs of eight TkSRPP/REF family genes were cloned, and RNAseq analysis showed that the methyl jasmonate(MeJA) treatment could up-regulate the expressions of TkSRPP3-4 and TkREF1 genes. The r

关 键 词：橡胶草 SRPP/REF家族 茉莉酸甲酯 天然橡胶合成 

分 类 号：S576[农业科学—作物学]