橡胶树DELLA基因HbRGL1的克隆与表达分析

DELLA蛋白属于植物特异性GRAS家族，是植物生长的负调控因子。为揭示橡胶树DELLA基因在橡胶树生长发育中的分子调控机制，本研究从橡胶树热研7-33-97中克隆HbRGL1的cDNA全长序列，含1 851 bp的ORF，编码616个氨基酸。生物信息学分析表明HbRGL1属于不稳定的亲水蛋白，定位在细胞核上，含有DELLA和GRAS保守结构域。系统进化关系分析表明HbRGL1与橡胶树HbGAIL、木薯MeGAIL、蓖麻RcGAI、麻风树JcGAI聚为一类。qRT-PCR分析表明HbRGL1在橡胶树不同组织中的表达量差异显著，在花中的表达量最高。在生长素（IAA）、乙烯利（ET）和脱落酸（ABA）等不同激素处理叶片中HbRGL1表达量均呈现显著上调趋势，尤其对赤霉素（GA₃）的应答具有反应快速且上调表达倍数最高。本研究为进一步阐明HbRGL1在橡胶树生长发育中的功能奠定理论基础。

Cloning and Expression Analysis of DELLA gene HbRGL1 from Hevea brasiliensis Müll. Arg

DELLA protein belongs to the plant-specific GRAS family and is a negative regulator of plant growth. To reveal the molecular regulation mechanism of DELLA gene in rubber tree growth and development， the full-length cDNA sequence of HbRGL1 was cloned from rubber tree cultivar Reyan 7-33-97. The ORF of HbRGL1 was 1 851 bp， and encoded 616 amino acids. Bioinformatics analysis showed that HbRGL1 was an unstable hydrophilic protein containing two conserved domains of DELLA and GRAS， and localized in the nucleus. Phylogenetic analysis showed that HbRGL1 was clustered with HbGAIL of rubber tree， MeGAIL of Manihot esculenta， RcGAI of Ricinus communis， and JcGAIof Jatropha curcas. qRT-PCR analysis showed that the expression level of HbRGL1 in different tissues of rubber treewas significantly different， and its expression level was the highest in flower. HbRGL1 expression was significantly up-regulated in leaves treated by different hormones such as auxin（IAA）， ethephon（ET） and abscisic acid（ABA）. Especially， and it rapidly responded to GA₃ treatments， and had the highest up-regulation of expression level. The study provided theoretical basis for further elucidating the function of HbRGL1 in the growth and development of rubber tree.