巨桉糖原合成酶激酶3 EgrSK41的克隆与表达分析

Cloning and Expression Analysis of Glycogen Synthase Kinase 3 EgrSK41 in Eucalyptus grandis

糖原合成酶激酶3 (GSK3)是一种普遍存在于真核生物中且非常保守的丝氨酸/苏氨酸蛋白激酶,调控植物的生长发育和胁迫响应等多种生理过程。本研究以巨桉无性系GL1为研究材料,克隆了一个巨桉GSK3基因,命名为EgrSK41 (登录号:MT628392)。生物信息学分析表明,EgrSK41可编码422个氨基酸,分子量为48.03 kD,等电点为8.37,属于稳定蛋白、亲水蛋白,可能定位于细胞核,具有27个磷酸化位点。系统进化分析和蛋白质结构域分析表明,EgrSK41的蛋白序列具有保守的Protein Kinase domain及TREE结构域,属于Ⅳ亚族。表达模式分析表明:EgrSK41在成熟叶中的表达量相对较高;在节间的表达量显著高于茎顶端,且随着节间次生发育越成熟,表达量逐渐降低;EgrSK41的表达量受盐、缺氮、缺硼、缺磷等逆境胁迫的诱导而上调。由此说明,EgrSK41与GL1茎的次生发育有密切的关系且对GL1响应逆境胁迫具有重要的调控作用。

Glycogen synthase kinase 3(GSK3) is a highly conserved Ser/Thr protein kinase widely found in eukaryotes,which regulates plant growth,development,abiotic stress resistance,and other physiological processes.In this study,a GSK3 gene named EgrSK41(Accession ID:MT628392) was cloned from Eucalyptus grandis clone GL1.The results of bioinformatics analysis showed that EgrSK41 encodes 422 amino acids with a molecular weight of 48.03 kD and an isoelectric point of 8.37,belonging to stable protein and hydrophilic protein,probably localized to nuclear,and had 27 phosphorylation sites.The results of phylogenetic analysis and conserved domain analysis showed that EgrSK41 protein sequence with a conserved protein kinase domain and TREE domain belonged to the GSK3 Ⅳ subfamily.The expression patterns of EgrSK41 were studied by using real-time quantitative PCR technology.It revealed that the EgrSK41 expression level was relatively high in mature leaves.Its expression level was significantly high in nodes prefer to the apex.With the maturation of internode secondary development,its expression level decreased gradually.Moreover,its expression level was up-regulated when induced by salt stress,nitrogen,boron,and phosphorus deficiency stresses,though the expression patterns were not the same exactly.These results indicate that EgrSK41 is closely related to the secondary development of stem and plays an important regulatory role in response to abiotic stresses in GL1.