辣椒抗菌蛋白cDNA的分离与表达的初步分析

Cloning of Capsicum annuum Antifungal Protein cDNA and Preliminary Analysis of Its Expression

本研究从经辣椒疫霉侵染处理的辣椒叶片cDNA文库中分离获得了一个辣椒抗菌蛋白cDNA阳性克隆,其长度为255bp,含有长度为85个氨基酸的开放读码框架,与其它植物抗菌蛋白或几丁质酶有不同程度的同源性,推测为辣椒抗菌蛋白,命名为CansLTPS.cDNA-AFLP分析表明,CansLTPS的转录受UV-B照射和辣椒疫霉侵染的诱导,外源脱落酸(ABA)、乙烯(ETH)、水杨酸(SA)等可不同程度的诱导CansLTPS基因的转录,而MeJA处理对CansLTPS基因的转录表达影响不大,表明CansLTPS基因可应答生物和非生物逆境胁迫,其上游可能涉及ABA、ETH、SA等介入的信号传递途径.

Plants antimicrobial proteins （nsLTPS）, is very important in plant disease resistance. In the study, a cDNA positive clone of Capsicum annuum antifungal protein was isolated from a cDNA library constructed from leaves challenged with phytophthora. The positive cDNA clone turned out to be 646 bps in length, harboring an open reading frame of 85 amino acids, which shared different degree of homology with chitinase or antimicrobial proteins from other plants, so the positive was named CansLTPS（Plants Antimicrobial Proteins of Capsicum annuum）. The result of cDNA-AFLP analysis indicated that expression of CansLTPS was induced by UV.B illumination and phytophthora infection, and also by the treatment of exogenous phytohormones ABA, ETH and SA, but not by MeJA. The results indicated that CansLTPS might reply biotic and the abiotic stresses by the signal pathway mediaed by ABA, salicylic acid and ethylene.