巴西橡胶树HbRALF34的克隆及表达分析

Cloning and expression analysis of HbRALF34 from Hevea brasiliensis

依据橡胶树胶乳转录组数据,利用RT–PCR技术鉴定了一个快速碱化因子(rapid alkalinization factor,RALF)家族基因cDNA序列。该cDNA长度为767 bp,开放阅读框长度为411 bp,编码136个氨基酸。序列比对显示该RALF基因与AtRALF34有较高相似性,因而命名为HbRALF34。以热研7–33–97无性系橡胶树为材料,采用实时荧光定量PCR对不同组织及乙烯、茉莉酸、伤害、过氧化氢、高盐、低温、干旱等处理下HbRALF34的表达模式进行分析。结果表明:HbRALF34在橡胶树叶片、花、树皮以及胶乳中均有表达,其中胶乳中表达量最高;与健康橡胶树相比,HbRALF34在死皮橡胶树胶乳及树皮中的表达量显著上调;乙烯、茉莉酸、过氧化氢及伤害处理能诱导该基因表达,而低温、干旱及高盐处理则抑制该基因表达,表明HbRALF34可能参与橡胶树的信号传导、产排胶调控以及胁迫响应。

Based on the latex transcriptome date,a cDNA sequence of rapid alkalinization factor(RALF)family gene was identified by RT–PCR.The cDNA is767bp in size with a411bp open reading frame and encodes136amino acids.BLASTX searches of GenBank showed that the deduced amino acid sequences of RALF gene was similar to AtRALF34,thus was named as HbRALF34.Expression profiles of HbRALF34in different tissues of Hevea brasiliensis clone Reyan7–33–97and in response to ethylene(ET),jasmonic acid(JA),wounding,hydrogen peroxide(H2O2),high salt,low temperature and drought were assayed via real–time quantitative PCR(RT–qPCR).The results suggested that HbRALF34was ubiquitously expressed in the leaves,flowers,barks and latex of rubber tree,and its highest expression was in latex.Compared with healthy rubber tree,the expression level of HbRALF34was increased in latex and bark of tapping panel dryness rubber tree.Moreover,the expression of HbRALF34was induced by ET,JA,H2O2and wounding treatments,but was inhibited by high salt stress,low temperature and drought treatments.All these results suggest that HbRALF34is likely involved in signal transduction,regulating rubber biosynthesis and latex flow,as well as responding to stress in Hevea brasiliensis.