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胚胎发育晚期丰富蛋白(Late embryogenesis abundant,LEA)是植物在逆境胁迫下产生的一种应激蛋白质,具有较高的亲水性和热稳定性,与植物抗逆功能密切相关,研究LEA家族基因对于甘薯抗逆性分子育种具有重要意义.通过对甘薯(徐薯18)转录组数据库搜寻时发现编码LEA2的转录本,随后对该转录本进行了克隆和测序分析,利用数字表达谱(Digital Gene Expression Profi ling,DGE)和半定量RT-PCR分析了Ib-LEA2在不同组织和不同发育阶段的表达图谱.为进一步了解Ib-LEA2在生物体响应盐胁迫中的作用,将Ib-LEA2连接原核表达载体pET-32a,用大肠杆菌BL21(DE3)菌株进行盐胁迫的耐受分析.结果显示:Ib-LEA2完整的开放阅读框(ORF)长度为942 bp,编码313个氨基酸残基.进一步研究发现,在甘薯组织内同时存在3个高度同源的LEA 2基因型(核苷酸序列>99%),分别命名为Ib-LEA2a、Ib-LEA2b和Ib-LEA2c.数字表达谱和半定量RT-PCR的结果显示Ib-LEA2在不同组织和发育阶段具有不同的表达图谱,在茎中的表达量远远高于叶和根.大肠杆菌BL21(DE3)菌株盐胁迫的结果显示,较之对照菌株,表达Ib-LEA2的菌株能够更好地耐受高浓度的NaCl.研究表明,Ib-LEA2对盐胁迫有一定的响应能力,能够保护细胞免受高盐的毒害.
Late embryogenesis abundant (LEA) is a kind of stress protein produced by plant under stress. It has high hydrophilicity and thermal stability and is closely related to plant anti-retrogradation function. LEA family gene Which is of great importance to the resistance breeding of sweet potato.Sequencing of the transcriptome of sweetpotato (Xoushu 18) transcriptome database revealed that the transcript encoding LEA2 was cloned and sequenced. The digital expression profile (Digital Gene Expression Profiling, DGE) and semi-quantitative RT-PCR analysis of Ib-LEA2 expression profiles in different tissues and different developmental stages.In order to further understand the role of Ib-LEA2 in the response of organisms to salt stress, Ib-LEA2 was ligated into prokaryotic The results showed that the complete open reading frame (ORF) of Ib-LEA2 gene was 942 bp in length, encoding 313 amino acid residues.Further study was carried out on the expression of pET-32a in Escherichia coli BL21 (DE3) Three highly homologous LEA 2 genotypes (nucleotide sequence> 99%) were found in sweet potato tissues, which were named as Ib-LEA2a, Ib-LEA2b and Ib-LEA2c, respectively. -PCR The results showed that Ib-LEA2 had different expression profiles in different tissues and developmental stages, and its expression level in stems was much higher than that in leaves and roots. The results of salt stress in E. coli BL21 (DE3) strain showed that compared with the control strain, The strain Ib-LEA2 is better able to tolerate high concentrations of NaCl.It has been shown that Ib-LEA2 has some response to salt stress and protects cells from high salt stress.