Erwinia chrysanthemi分离株CSCL006 hrpN基因的克隆与高效表达  

Molecular Characterization and Overexpression of Erwinia chrysanthemi Strain CSCL006 hrpN_(CSCL006) Gene, which Encodes An Elicitor of the Hyperdensitive Reaction

作　　者：汤承[1] 崔亚亚[2] 吴伯骥[2] 李名扬[1] 

机构地区：[1]西南大学园艺园林学院 [2]中国科学院成都生物研究所,成都610041

出　　处：《农业生物技术学报》2006年第5期763-767,I0004,共6页Journal of Agricultural Biotechnology

摘　　要：通过构建Erwiniachrysanthemi分离株CSCL006的DNA文库,克隆出hrpNCSCL006基因,测序结果显示该基因编码区长1020bp;推导的harpinCSCL006与ErwiniachrysanthemiEC16和3937编码的harpin蛋白同源性高,但与其它软腐菌的harpin蛋白同源性较低;在大肠杆菌中(Escherichiacoli)高效表达了hrpNCSCL006基因,重组harpinCSCL006蛋白分子量为34kD。以抗harpinEcc的抗体为探针,Westernblot证实该蛋白确为harpin;纯化的harpinCSCL006,能引起烟叶的过敏反应。The DNA library of Erwinia chrysanthemi isolation CSCL006 was constructed. The hrpNCSCL006 gene was cloned from the DNA library and the nucleotide sequence was determined. The nucleotide sequence of hrpNCSCL006 revealed a coding region of 1 020 bp which matched well with the size of hrpNCSCL006 transcript determined by Northern blot. Alignment of the deduced amino acid sequence of harpin CSCL006 with harpin sequences of other soft-rot Etwinia species in database demonstrated that harpin CSCL006 shares high homology with harpins of Erwinia chrysanthemi strains ECI6 and 3937, but relatively lower homology with harpins of Erwinia caro- tovora subspcorotovora, hrpNCSCL006 was cloned into a expression vector pET28a （＋） and overexpressed in Escherichia coli. The ca. 34 kD overexpressed polypeptide matched well with the size of predicted harpinCSCL006. Using anti-harpinEcc antibodies as probe, Western blotting analysis confirmed that the overexpressed protein was harpinCSCL006. The harpin CSCL006 fractionated from E. coli could elicite the hypersensative reaction in tobacco （Nicotiana tabacum） leaves.

关 键 词：ERWINIA chrysanthemi hrpN基因 HARPIN蛋白 过敏反应 

分 类 号：S188[农业科学—农业基础科学]