橡胶树叶片衰老相关基因HbLEA3的克隆与表达分析  

Cloning and Expression Analysis of HbLEA3,a Gene Associated with Leaf Senescence in Hevea brasiliensis

作　　者：邹智 郭运玲[1] 孔华[1] Zou Zhi;Guo Yunling;Kong Hua(Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-season Reproduction Regions/Institute of Tropical Bioscience and Biotechnology,Chinese Academy of Tropical Agricultural Sciences,Haikou Hainan 571101,China)

机构地区：[1]中国热带农业科学院热带生物技术研究所/海南省南繁生物安全与分子育种重点实验室,海南海口571101

出　　处：《西南林业大学学报（自然科学）》2021年第4期42-48,共7页Journal of Southwest Forestry University：Natural Sciences

基　　金：海南省自然科学项目(319MS093)资助;国家自然科学项目(31700580,31971688)资助。

摘　　要：为揭示HbLEA3的序列特征和转录调控模式,研究以橡胶树衰老叶片为材料,利用RT−PCR技术克隆了该基因652 bp的cDNA序列,其中包含173 bp的5′UTR、303 bp的ORF以及176 bp的3′UTR。结果表明:基因编码100个氨基酸,理论分子量为11.61 kDa,等电点为9.07,GRAVY为−0.498,含有一个LEA_(3)家族特有的保守结构域,线粒体定位;蛋白与木薯、蓖麻、麻疯树和可可树中同源蛋白的相似性均在60%以上,而在拟南芥和水稻中亲缘关系最近为AtLEA3和OsLEA10,相似性分别为36.0%和41.1%;HbLEA3主要在叶片中表达,并随着叶片的成熟而稳步上调,但在衰老早期短暂下调,随后在衰老中期显著上调;此外,基因的表达还受低温、PEG、NaCl、H2O2、ABA、乙烯利、茉莉酸甲酯和水杨酸等多种非生物胁迫和逆境相关植物生长调节剂的诱导。因此,HbLEA3是一个与橡胶树叶片发育和胁迫响应相关的胚胎发育晚期丰富蛋白基因。To uncover the sequence characteristics and transcriptional regulation pattern of a senescence-associated gene HbLEA3,its 652-bp cDNA(including a single ORF of 303-bp,173-bp 5'UTR,and 176-bp 3'UTR)was isolated from senescing leaves of Hevea brasiliensis by using RT−PCR.The findings indicated that this gene was predicted to encode a polypeptide of 100 amino acids with a calculated molecular weight of 11.61 kDa and isolectric point of 9.07.Composed of a hydrophobic N-terminal and a hydrophilic C-terminal with a grand average of hydrophilicity of−0.498,the protein is predicted to contain a conserved LEA_(3) domain and a transit peptide for mitochondrial localization.Homologous analysis revealed that HbLEA3 shares a similarity of more than 60%with homologs in Manihot esculenta,Manihot esculenta,Jatropha curcas,and Theobroma cacao,and its closest homolog in Arabidopsis thaliana or Oryza sativa is AtLEA3(36.0%)and OsLEA10(41.1%),respectively.Expression analysis showed that HbLEA3 is mainly expressed in leaves with a steadily increasing pattern during leaf development except for a transient decline in early-senescing leaves.Moreover,its transcript level appeared to be regulated by various abiotic stresses and plant growth regulators,including cold,PEG,NaCl,H2O2,ABA,eth-ephon,MeJA,and SA.Taken together,our results suggest a key role of HbLEA3 in hormone and abiotic stress re-sponses as well as leaf development.

关 键 词：橡胶树 基因克隆 HbLEA3 转录 非生物胁迫 植物生长调节剂 

分 类 号：S794.1[农业科学—林木遗传育种]