论文部分内容阅读
核因子Y的B亚基(NF-YB)可以在植物的生长、发育和抗逆响应中调节多种基因的表达,在植物的各种生理活动中发挥重要作用。紫花苜蓿是重要的牧草,具有较强的抗逆能力。本研究从紫花苜蓿中克隆了一个NF-YB基因,即MsNF-YB4(Gen Bank登录号为KX966286)。该基因的开放阅读框长度为405 bp,编码134个氨基酸残基。经过比对发现,该基因与蒺藜苜蓿的NF-YB4(Mt NF-YB4)在m RNA的编码区内同源性为92%,而在蛋白水平上的同源性为94%。通过比对分析,发现MsNF-YB4含有典型的NF-YB转录因子保守结构域。我们通过qPCR的方法对MsNF-YB4基因的表达模式进行了分析,结果发现,在盐碱和干旱胁迫下,根瘤和根中的表达量显著上调,暗示该基因在盐碱和干旱胁迫的响应中发挥作用。我们构建了植物表达载体pCBC-MsNF-YB4,并通过农杆菌介导法获得了过量表达MsNF-YB4基因的转基因烟草。对T1代转基因烟草的耐盐性测试结果表明,MsNF-YB4基因的表达提高了转基因烟草的耐盐性,转基因烟草幼苗可以在含有1.4%Na Cl的培养基上生长。这些结果表明,MsNF-YB4在紫花苜蓿的盐胁迫响应中发挥重要作用。
The B subunit of nuclear factor Y (NF-YB) regulates the expression of multiple genes in plant growth, development and resistance to stress and plays an important role in various physiological activities of plants. Alfalfa is an important pasture and has strong resistance to stress. In this study, a NF-YB gene was cloned from alfalfa, ie MsNF-YB4 (Gen Bank accession number KX966286). The open reading frame of this gene is 405 bp in length and encodes 134 amino acid residues. After comparison, the gene and the Medicago truncatula NF-YB4 (Mt NF-YB4) showed a homology of 92% in the m RNA coding region and a 94% homology at the protein level. By comparison and analysis, MsNF-YB4 was found to contain a typical NF-YB transcription factor conserved domain. We analyzed the expression pattern of MsNF-YB4 gene by qPCR and found that the expression level of MsNF-YB4 gene was significantly up-regulated in root nodules and roots under salt stress and drought stress, suggesting that this gene is under salt and alkali stress and drought stress responses Play a role. We constructed the plant expression vector pCBC-MsNF-YB4 and obtained transgenic tobacco that over-expressed MsNF-YB4 gene by Agrobacterium-mediated method. The results of salt tolerance test showed that the expression of MsNF-YB4 increased the salt tolerance of transgenic tobacco and the transgenic tobacco seedlings could grow on the medium containing 1.4% NaCl. These results indicate that MsNF-YB4 plays an important role in the salt stress response of alfalfa.