中文摘要：

微管蛋白是微管的重要组成部分,参与维持细胞骨架的稳定及延伸。本研究采用RT-PCR和RACE技术从巴西橡胶树（Hevea brasiliensis）中克隆到一个α-微管蛋白基因,命名为Hb TUA2（Gen Bank登录号：KX809698）。该基因c DNA全长1 940bp,其中开放阅读框1 353 bp,编码含450个氨基酸残基的蛋白质序列。Hb TUA2与其他植物TUA蛋白高度同源,具有TUA蛋白家族保守的GTP结合位点和转录后调控片段。基因结构分析表明,Hb TUA2具有4个外显子和3个内含子,内含子外显子剪切符合＂GT-AG＂规则。荧光定量PCR分析表明,Hb TUA2在巴西橡胶树叶片、雌花、雄花、茎尖、树皮及胶乳等组织中均有表达,在雌花中表达量最高,其次是茎尖和雄花,在叶片、树皮和胶乳中表达量较低。此外,Hb TUA2的表达还受高盐、干旱、低温、过氧化氢（H2O2）、乙烯利和茉莉酸甲酯（Me JA）调控,表明Hb TUA2可能参与巴西橡胶树乙烯和茉莉酸信号途径及逆境胁迫应答过程。

英文摘要：

As the major proteins assemble into microtubules,tubulins are involved in maintaining the stability and elongation of the cytoskeleton. Here we report an α-tubulin gene（TUA）,Hb TUA2,from Hevea brasiliensisby reverse transcription-polymerase chain reaction（RT-PCR） and rapid-amplification of c DNA ends（RACE）. The Hb TUA2 c DNA sequence is 1 940 bp in length,and contains an open reading frame（ORF） of 1 353 bp encoding a polypeptide of 450 residues. Hb TUA2 owned the typical conserved GTP binding site and a post transcriptional active domain of TUA and showed high homology with TUA proteins from other plants. Genomic organization analysis showed that Hb TUA2 contained four exons and three introns,and all intron/exon boundaries were in accordance with the GT/AG rule. Real-time PCR results showed that Hb TUA2 was expressed in leaf,flower,stem tip,bark and latex of Hevea brasiliensis,with the highest expression in female flower and the lowest expression in latex. Moreover,the expression of Hb TUA2 was regulated by Na Cl,drought,low temperature,hydrogen peroxide（H2O2）,ethephon（ET） and methyl jasmonate（Me JA） treatments. All these results suggested that Hb TUA2 might play important roles in stresses responses as well as ET and JA signals in Hevea brasiliensis.