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DNA J蛋白是植物中广泛存在的一类分子伴侣,对于维持正常和逆境条件下蛋白质的稳态具有重要作用。我们在前期通过对强抗逆植物蒙古沙冬青进行转录组分析,发现一个寒旱诱导表达的J蛋白即Am J20编码序列,但其3’端编码区不完整。本研究通过3’RACE获得其c DNA全长序列(800 bp),推测其编码蛋白由179个氨基酸残基组成,含一个典型的J结构域,属于Ⅲ型J蛋白,此外还具有叶绿体和细胞核双定位信号;利用半定量RT-PCR方法检测该基因在野外生长植株中的时空表达模式,发现其在春、夏、秋季只有微量表达,甚至检测不到转录本,而在严冬时节高表达,此外在叶片中的表达量明显高于根、嫩枝、花蕾和幼嫩果荚;利用RT-PCR方法克隆到该基因编码区c DNA并将其插入到植物超表达载体上,为通过转基因植物分析该基因的功能提供了理论依据。
DNA J protein is a widely existing class of chaperones in plants and plays an important role in maintaining protein homeostasis under normal and adversity conditions. We conducted a transcriptome analysis of the highly resistant plant Mongolia asarum in the early stage and found a cold-inducible J protein called the Am J20 coding sequence, but the 3 ’end coding region was incomplete. In this study, the full-length c cDNA sequence (800 bp) was obtained by 3’RACE. The deduced protein encoded by 179 amino acid residues contains a typical J domain, which belongs to type III J protein. In addition, it has chloroplast and nucleus Bi-directional signal. The temporal and spatial expression patterns of the gene in the field were detected by semi-quantitative RT-PCR and found only slight expression in spring, summer and autumn, even undetectable transcripts and high expression in the winter, In addition, the expression level in leaves was significantly higher than that in roots, twigs, buds and young pods. The cDNA encoding this gene was cloned by RT-PCR and inserted into plant overexpression vector. Analysis of the function of the gene provides a theoretical basis.