摘要
基于电子克隆结果,采用RT-PCR技术从橡胶树的叶片中分离到1条858 bp的cDNA。结果表明:该序列含有1个798 bp的开放读码框,将基因命名为HbCAB2;HbCAB2预测编码265个氨基酸,其中包含35个残基的叶绿体信号肽,成熟蛋白的理论分子量为24.66 kDa、等电点为4.99;前体蛋白含有1个保守的捕光叶绿素a/b结合蛋白结构域(Chloroa_b-bind,PF00504),包含3个跨膜螺旋和2个短螺旋、1个三聚化基序以及多个叶绿素和类胡萝卜素结合位点,可归为LHCB1亚类;HbCAB2与HbCAB1属于反式串联重复,两者在蛋白水平的序列相似性高达97.0%。表达分析显示,HbCAB2倾向于在叶片和雌花中表达,且其表达水平随着叶片的成熟而逐渐增加,但在衰老叶片中显著下调。此外,基因的表达还受病原侵染、干旱和低温胁迫抑制。
Based on the in silico cloning result,an 858-bp cDNA that includes a 798-bp long ORF(open reading frame,designated HbCAB2)was isolated from the Hevea brasiliensis leaf by using the RT-PCR technique.Sequence analysis indicated that this gene putatively encodes 265 amino acids with a chloroplast signal peptide of 35 residues,and the mature protein was predicted to have a theoretical molecular weight(Mw)of 24.66 kDa and an isolectric point(pI)of 4.99.HbCAB2 can be categoried into subtype LHCB1,which was shown to contain one conserved light-harvesting chlorophyll a/b binding domain(Chloroa_b-bind,Pfam ID PF00504)as well as 3 transmembrane helices and 2 short helices,1 trimerization motif,some chlorophyll and carotenoid binding sites.HbCAB2 was shown to be a reverse tandem duplication of HbCAB1,which shares a sequence similarity of 97.0%at the protein level.Expression analysis revealed that HbCAB2 was preferentially expressed in leaves and female flowers,with a gradually increased expression pattern during leaf maturity but a sharply decrease in senescent leaves.Additionally,its transcript level was shown to be inhibited by pathogen infection,low temperature,and drought stresses.
作者
阳江华
张希财
邹智
Yang Jianghua;Zhang Xicai;Zou Zhi(Rubber Research Institute,Chinese Academy of Tropical Agricultural Sciences/Danzhou Investigation & Experiment Station of Tropical Crops,Ministry of Agriculture/Institute of Tropical Biosciences and Biotechnology,Chinese Academy of Tropical Agricultural Sciences,Haikou Hainan 571101,China)
出处
《西南林业大学学报（自然科学）》
CAS
北大核心
2019年第1期88-94,共7页
Journal of Southwest Forestry University：Natural Sciences
基金
国家自然科学资金项目(31700580)资助
中国热带农业科学院基本科研业务费专项资金(1630022017022)资助
关键词
橡胶树
叶绿素
结合蛋白
Lhcb1
病原侵染
干旱
低温
Hevea brasiliensis
chlorophyll
binding protein
Lhcb1
pathogen infection
drought
low temperature
