青杆PwUSP1基因的克隆及表达模式分析

广泛逆境胁迫蛋白（universalstressprotein，USP）在非生物胁迫响应中起重要作用，但在植物中其功能还大部分未知。本研究通过BLAST分析青杆EST文库，得到职zP基因的EST序列，通过RACEPCR方法获取USP基因的末端序列，经过与EST序列拼接得到USP基因的cDNA全长序列，命名为PwUSP1。分析发现PwUSP1全长cDNA为1167bp，编码区为519bp，编码172个氨基酸残基。生物信息学分析显示，PwUSP1编码的蛋白相对分子质量为19．07kDa，理论等电点为6．38，为非跨膜的亲水性蛋白。PwUSP1具有USP家族典型的UspA结构域和ATP结合位点G-（2x）-G-（9x）-G（S／T）。半定量RT-PCR与RT-qPCR分析表明，PwUSP1在青杆的根、茎、针叶、花粉、种子中均有表达，在根和花粉中表达量较高。同时，PwUSP1受干旱和盐胁迫的诱导表达上调，均在处理6h后表达量较高，推测该基因可能在青杆逆境胁迫响应中发挥作用。

Cloning and Expression Analysis of PwUSP1 from Picea wilsonii

Universal stress proteins （USPs） play active roles in the abiotic stress responses of living bodies, but their functions remain largely unknown in plants. The full length cDNA of PwUSP1 was obtained by RACE PCR that spliced the terminal sequences of PwUSP1 with the EST based on the cDNA library ofPicea wilsonii. The full length cDNA of PwUSP1 was 1 167 bp and the ORF was 519 bp which encoded 172 aa. Bioinformatics analysis showed that the theoretical molecular weight of PwUSP1 was 19.07 kDa and the isoelectric point was 6.38. PwUSP1 was a stable hydrophilic protein with non-transmembrane domain structure. PwUSP1 had the typical UspA domain of USP family with an ATP-binding site G-（2X）-G-（9X）-G（S/T）. Semi- quantitative RT-PCR and RT-qPCR analysis discovered that PwUSP1 was expressed in the root, stem, needle, pollen and seed of Picea wilsonii and was highly expressed in the root and pollen. PwUSP1 was up-regulated by drought and salt stresses and both was expressed most at 6 h after stress treatments, indicating that the PwUSP1 gene might play an important role in responses to some stresses.