能产生植物抗性诱导蛋白harpin的自生固氮工程菌的构建

通过三亲交配的方法 ,把带有梨火疫欧文氏杆菌hrp基因簇的重组粘粒pCPP4 30接合转移进入固氮菌催娩克氏菌X2R中。经质粒提取检测、PCR专一扩增、Southernblotting分析和生物测定结果表明 ,工程菌X2R( pCPP4 30 )构建成功。该菌诱发过敏反应的能力是大肠杆菌DH5( pCPP4 30 )的 10倍以上。在温室小区用X2R(pCPP4 30 )菌液处理番茄 ,番茄早疫病的感染指数比出发菌降低 13.0 9% ,果实数量和单果重分别比对照增加 2 2 .31%和 2 0 .0 8% ,本工作表明 :hrp基因簇在自身固氮菌中可以表达和分泌harpin。

Construction of A Recombinant Strain of the Free Living Nitrogen-fixing K.oxytoca NG13R Capable of Producing Harpin

WT5BZ]Cosmid clone pCPP430 with the functional hrp gene cluster of Erwinia amylovora was transferred into K.oxytoca X2R by tri parental mating. Plasmid screening, PCR amplification of hrpN, Southern blotting and hypersensitive response in tobacco and tomato demonstrated the successful transfer of pCPP430 into X2R. The intensity of HR caused by X2R(pCPP430) is ten times then that caused by DH5(pCPP430). Spraying of cell suspension of X2R(pCPP430) for four times onto tomato plants in green house decreased the severity of naturally occurring early blight by 31.37%. Fruits per plant and average weight per fruit were increased by 22.31% and 20.08% respectively against the X2R control.