蜡梅nsLTPs基因家族3个成员的分子特征及非生物胁迫应答分析

为了探索脂转移蛋白在蜡梅开花抗寒性形成方面的可能功能，在构建蜡梅花cDNA文库及 EST分析的基础上,通过对文库cDNA克隆全长测序 ,得到了3个蜡梅非特异性脂转移蛋白的基因，分别命名为CpLTPI.1，CpLTPI.2，CpLTPI.3。它们的cDNA全长分别为611 bp，1016 bp和656bp ，ORF大小基本一致，分别为360bp，360bp和351bp，但 5′端和3′端的非翻译区的长度不等，存在的调控基序有所不同。3个基因的编码蛋白均具有植物非特异性脂转移蛋白的典型结构，即4对二硫键，4个ɑ-螺旋，有一个可结合和容纳脂肪酸分子的类似口袋状的疏水结构，分子量约为9 kD，为nsLTPI类。实时荧光定量PCR技术分析比较蜡梅叶片中 3个基因对非生物胁迫的应答情况，结果表明3个nsLTP基因在蜡梅幼苗中的表达受干旱、ABA、低温和NaCl处理的影响程度不同，表明这些基因可能在蜡梅幼苗的水分平衡、耐受低温、离子代谢等过程中发挥着不同的作用。

Molecular Characters and Abiotic Stresses Respond Analysis of Three Members of the nsLTP Family from Chimonanthus praecox (L.) Link

To investigate the role of lipid transfer proteins in chilling resistance of blossom of Chimonanthus Praecox , we cloned three members of the LTPs family, namely CpLTPI.1, CpLTPI.2 and CpLTPI.3, by randomly cloning and sequencing, based on the cDNA library constructed from Chimonanthus Praecox flower and its EST analysis. The three genes have full-lengths of 611 bp, 1016 bp and 656bp, respectively, with similar opening reading frame(ORF) of 360 bp, 360 bp and 351bp, and have different length of 5′and 3′ untranslated region with different regulation motifs. The three genes, which belong to the nsLTPI family, have the typical structure of the plant nonspecific lipid transfer protein including 4 pairs of disulfide, 4 α-helices and 1 tunnel-like hydrophobic cavity which can contain lipid molecules. Real-time quantitative PCR analysis revealed that the three genes were differently regulated by drought, salinity, cold and ABA (abscisic acid), which suggested that the three genes would play different roles in water balance, chilling tolerance, metabolism and other physiological processes in Chimonanthus Praecox.