摘要
为了探索蔗糖非发酵相关蛋白激酶 2(Sucrose non-fermentating1-related protein kinase 2,SnRK2)在巴西橡胶树响应低温胁迫应答中的作用,采用RT-PCR技术,从橡胶树抗寒无性系 93-114的叶片中克隆了SnRK2亚家族的一个成员,命名为HbSnRK2.7.该基因包含一个 1 095 bp的开放阅读框,编码 364个氨基酸.HbSnRK2.7的分子量为 41.39 kD,等电点为 4.70,具有保守丝氨酸/苏氨酸蛋白激酶结构域,预测其能催化磷酸基从ATP转移到蛋白质底物上的丝氨酸/苏氨酸残基上,也是磷酸化位点的集中区域,还具有非生物胁迫所需的结构域和ABA(脱落酸)依赖的HbSnRK2.7激活所需结构域.q-PCR结果显示,HbSnRK2.7基因响应ABA诱导,呈下调表达模式.在ABA处理 8h时,表达量下调到最低点.在低温胁迫下,HbSnRK2.7的表达量极显著降低.低温胁迫 4h和 8h时,HbSnRK2.7持续下调表达,低温胁迫 24h时,HbSnRK2.7表达量下调到最低,大约为非胁迫表达量的 1/2.而且,HbSnRK2.7在不抗寒种质中的表达量显著高于抗寒种质.这些结果表明,HbSnRK2.7可能作为负调控因子介导橡胶树依赖ABA的低温胁迫抗性形成.
Abstract
To explore the role of sucrose non-fermentation associated protein kinase 2(SnRK2)in the response of Hevea brasiliensis to low temperature stress,a member of the SnRK2 subfamily,named HbSnRK2.7,was cloned from the leaves of the cold-resistant clone Reyan'93-114'of Hevea brasiliensis by using RT-PCR.The gene cloned contains an open reading frame of 1 095 bp that encodes a protein of 364 amino acids.HbSnRK2.7 has a conserved serine/threonine protein kinase domain with a molecular weight of 41.39 kD and an isoelectric point of 4.70.It is predicted that it can catalyze the transfer of phosphate groups from ATP to the serine/threonine residues on the protein substrate,which is also the concentrated region of phosphorylation sites.It also has domains needed for abiotic stress and ABA-dependent domains for HbSnRK2.7 activation.Quantitative PCR(qPCR)results showed that HbSnRK2.7 gene was down-regulated in response to ABA induction.When treated with ABA for 8 h,the expression was down-regulated to the lowest point.Under low temperature stress,the expression of HbSnRK2.7 decreased significantly.The expression of HbSnRK2.7 was down-regulated continuously under low temperature stress for 4 h and 8 h,and the expression of HbSnRK2.7 was down-regulated to the lowest level at 24 h under low temperature stress,which was about 1/2 of non-stress expression.Moreover,the expression of HbSnRK2.7 was significantly higher in the cold-susceptible clones than in the cold-resistant clones.These results suggest that HbSnRK2.7 may act as a negative regulatory factor to mediate the formation of low temperature stress resistance of Hevea brasiliensisdependent on ABA.
基金项目
广东省重点领域研发计划(2020b020217002)
海南省科技专项(ZDKJ2021012)
国家天然橡胶产业技术体系建设项目(CARS-33-YZ1)
NETL
NSTL
维普
万方数据