论文部分内容阅读
钙依赖蛋白激酶(calcium-dependent protein kinases,CDPKs)在从枝菌根、根瘤菌-宿主植物共生体系中起重要调控作用。然而,CDPKs在兰科菌根共生体系中的作用机制尚不清楚。本研究利用RT-PCR、RACE方法,首次从小菇真菌(Mycena sp.)侵染的铁皮石斛根中克隆到1个钙依赖蛋白激酶基因,命名为DoCPK1(GenBank注册号JX193703)。DoCPK1全长2 137 bp,编码一条由534个氨基酸组成的肽链,分子量59.61 kD,等电点6.03。DoCPK1蛋白包含CDPKs蛋白家族保守的丝氨酸/苏氨酸蛋白激酶催化结构域和4个Ca2+结合的EF-hand基元。DoCPK1与人参PgCPK1(ACY78680)同源性最高(85%),小麦、水稻、拟南芥CDPKs基因(ABD98803,ADM14342,Q9ZSA2)等次之,与单子叶植物CDPKs基因亲缘关系最近。DoCPK1为组成型表达,其转录本在各器官中相对表达量依次为根>茎>种子>叶。在小菇真菌侵染30 d的石斛根中,DoCPK1显著上调,为对照根中的5.16倍,表明DoCPK1参与小菇真菌-铁皮石斛菌根早期互作,可能在该共生体系中起作用。本研究为进一步阐明DoCPK1在小菇真菌-铁皮石斛菌根共生中的潜在功能奠定基础。
Calcium-dependent protein kinases (CDPKs) play an important regulatory role in the symbiotic system of mycorrhizal and rhizobium-host plants. However, the mechanism of action of CDPKs in orchid mycorrhizal symbiosis is unclear. In this study, we first cloned a calcium-dependent protein kinase gene from Dendrobium candidum root infected with Mycena sp. Using RT-PCR and RACE methods and named DoCPK1 (GenBank accession number JX193703). DoCPK1 is 2 137 bp in length and encodes a peptide of 534 amino acids with a molecular weight of 59.61 kD and an isoelectric point of 6.03. The DoCPK1 protein contains the serine / threonine protein kinase catalytic domain conserved by the CDPKs protein family and four Ca2 + -binding EF-hand motifs. DoCPK1 has the highest homology (85%) with that of PgCPK1 (ACY78680), followed by CDPKs genes of wheat, rice and Arabidopsis (ABD98803, ADM14342, Q9ZSA2). DoCPK1 is constitutively expressed, and the relative expression amount of DoCPK1 in each organ is root> stem> seed> leaf. DoCPK1 was significantly up-regulated in Dendrobium rhizomania rooted at the 30th day after fungus Agaricus inoculation, which was 5.16 times of that in the control roots, suggesting that DoCPK1 may play an important role in this symbiotic system due to the involvement of DoCPK1 in the early interaction of Agrobacterium tumefaciens. This study laid the foundation for further elucidation of the potential function of DoCPK1 in the symbiosis of Pleurotus fungi-D. candidum.