沙冬青AmCSDP基因特性及转基因烟草的抗寒性分析

冷休克结构域蛋白(CSPs)是含有不同数量冷休克结构域(cold shock domain,CSD)的低温响应蛋白,在低温胁迫中发挥重要作用。以沙冬青(Ammopiptanthus mongolicus)为材料,克隆得到了冷休克结构域蛋白基因AmCSDP。生物信息学分析显示AmCSDP(Gen Bank登录号:KX756575)全长540bp,编码180个氨基酸,二级结构由8.9%的α–螺旋、47.8%的β–折叠和43.3%的无规则卷曲组成,其N端含有冷休克结构域。进化分析表明沙冬青与花生同源性最高。构建了AmCSDP真核表达载体Pcambia2300-35S-AmCSDP-OCS,经农杆菌介导转入本氏烟中。对转基因T1代和野生型烟草进行4℃低温胁迫处理,结果证实转基因本氏烟比野生型的耐冷能力强。

Characterization of AmCSDP Gene from Ammopiptanthus mongolicus and the Analysis of Cold Resistance in Transgenic Tobacco Plants

Cold shock domain proteins (CSPs) are cold induced proteins which play a critical role for the adaptation of plant to low-temperature stress.They are widely distributed in bacteria,plants and animals.In this study,we have cloned a cold shock domain protein gene AmCSDP (GenBank accession number KU744005) from Ammopiptanthus mongolicus.Bioinformatics analysis showed that the ORF of AmCSDP is 540 bp,encoding 180 amino acids.The AmCSDP secondary structure consists of 8.9％ α-helix,47.8％ β-floding and 43.3％ random coil and contains an N-terminal CSD domain.Phylogenetic analysis showed that AmCSDP shared high similarity to the homologous gene (GenBank accession number XP_016170210.1) from Arachis ipaensis.To further confirm the function of AmCSDP,eukaryotic expression vector Pcambia2300-35S-AmCSDP-OCS was constructed and transformed into Nicotiana benthamiana by Agrobacterium.Moreover,the transgenic tobacco plants exhibited higher germination rates than the wild types under cold stress.The results suggested that AmCSDP could be a potential candidate for engineering cold tolerance in plants.