望江南中核糖体失活蛋白新基因cassinⅰ的克隆及特征分析.docVIP

望江南中核糖体失活蛋白新基因Cassin的克隆及阮小蕾刘丽芳，何云蔚，刘福秀，李华平华南农业大学植物病毒研究室广州 510642） Cloning and Signature Analysis of A Novel Gene of Ribosome Inactivating Protein from Cassia occidentalis RUAN Xiao-lei, LIU Li-fang, HE Yun-wei, LIU Fu-xiu, LI Hua-ping (Laboratory of Plant Virology, College of Nature Resource and Environment, South China Agricultural University, Guangzhou 510642) Abstract:【Objective】Ribosome inactivating proteins (RIPs) are group of important proteins that inhibit the growth of plant pathogens and development of insects. Cloning the RIPs genes is very important for research their resistant function and applications.【Method】A novel DNA fragment coding RIP was isolated from Cassia occidentalis by applying a PCR strategy in which a pair of universal degenerated primers deduced from the two blocks with strong conserved amino acid regions in multiple plants was used. Then the full length cDNA (CassinⅠ) of the fragment was obtained by rapid amplification of cDNA ends.【Result】The full length of CassinⅠwas 882 bp. Compared with two kinds of typical RIP from Cucurbitaceae, the homologies of the deduced amino acid sequences of CassinⅠshared 58.2% and 34.7% with that of β-luffin and Trichosanthin (TCS), respectively, and there was no significant homology compared with other sequences of RIPs in GenBank. Result of multiple alignment about TCS, β-luffin and CassinⅠshown that 9 amino acid residues forming the active site of the TCS were conserved in CassinⅠ except that 2 residues was different. All the RIP active sites of CassinⅠ sequence were contained in P1/P2 amplification region.【Conclusion】It is the first report that a novel RIP gene was cloned from the Cassia occidentalis.. The results reported in this paper foundation for further studies of RIP gene function and development of transgenic plants to control plant diseases and insects. Key words: Cassia occidentalis; Ribosome inactivating protein; Gene cloning; Signature analysis 0 引言 【研究意义】植物病害和虫害使农业生产蒙受严重损失。化学农药给生产带来很多严重问