摘要
通过接合试验,将转座子Tn5从三个供体菌中引入水稻白叶枯病菌(Xanthomonascampestris pv.oryzae Dye)日本系统小种3菌株(JXOⅢ)的细胞内,接合频率分别为0.2×10^(-6),0.4×10^(-7)和0.27×10^(-6)。随机挑选的接合子总DNA与^(32)P标记的含有Tn5的探针质粒(pJB4JI:Tn5)杂交,放射自显影显示出同源杂交带。在6000个JXOⅢ的Tn5诱变株中,发现13个菌株对8个供试水稻品种(早生爱国3号,IR26,IR20,IR8,cas209,南粳15,金南风和TN-1)都不致病,表现为不亲和反应。在含有酶解基质的平板上,比较了JXOⅢ和13个毒性基因突变体的胞外水解酶活性和多糖产量。结果发现所有突变体的蛋白酶活性和胞外多糖产量都增强;所有突变体的淀粉酶活性和大多数突变体的果胶酶活性都是从无到有;突变体纤维素酶活性基本不变;大多数突变体的酯酶活性有所降低。
Tn5 from E.coli 1830,WA803 and SM10 was introduced by conjugationmating into cells of Xanthomonas campestris pv.oryzae JXO Ⅲ.The conjugationfrequences ranged from 0.20×10^(-5) to 0.40×10^(-7) conjugants per recipientcell.The southern blot analysis of total DNA of randomly chosen conjugantswith Tn5-containing plasmid(pJB4Jl:Tn5) as the^(32)p-labelled probe,showedpJB4Jl::Tn5 hybridized only with the DNA of Tn5-induced mutants,notwith that of wildtype strain JXO Ⅲ. 13 of 6000 Tn5-induced mutants were no longer pathogenic on 8 ricecultivars(Wase Aikoku 3,IR26,IR20,IR8,Cas209,Nanjing 15,kinmazae andTN-1),the compatibile interaction of which with rice was alternated fromto the imcompatibile. The examination of extracellular hydrolytic enzymes and polysaccharideof JXO Ⅲ and 13 virulence gene mutants showed that the activity of proteo-lytic enzymes and production of polysaccharide of all mutants were increa-sed,the amyloIytic activity of all mutants and pectolytic activity of mostmutants were from negative to positive,cellulovlytic activity of JXO Ⅲ wassimilar to that of the mutants,the lipolytic activity of most mutants waslower than that of JXO Ⅲ.
出处
《植物病理学报》
CAS
CSCD
北大核心
1992年第3期217-222,共6页
Acta Phytopathologica Sinica
基金
国家863高技术发展项目资助
