Beaulieu C, Van Gijsegem F
Département de Biologie Moléculaire, Université Libre de Bruxelles, Rhode-St-Genèse, Belgium.
J Bacteriol. 1990 Mar;172(3):1569-75. doi: 10.1128/jb.172.3.1569-1575.1990.
We present a method for identifying plant-inducible genes of Erwinia chrysanthemi 3937. Mutagenesis was done with the Mu dIIPR3 transposon, which carries a promoterless neomycin phosphotransferase gene (nptI), so upon insertion, the truncated gene can fuse to E. chrysanthemi promoters. Mutants containing insertions in plant-inducible genes were selected for their sensitivity to kanamycin on minimal plates and for their acquired resistance to this antibiotic when an S. ionantha plant extract was added to kanamycin minimal plates. The selection allowed the identification of E. chrysanthemi promoters inducible by host factors present in the S. ionantha plant extract. Using this method, we isolated 30 mutants and characterized 10 of them. Two mutants were defective in cation uptake, one was defective in the galacturonate degradation pathway, and another was altered in the production of the acidic pectate lyase. The functions of the other mutated genes are still unknown, but we show that most of them are involved in pathogenicity.
我们提出了一种鉴定菊欧文氏菌3937中植物诱导基因的方法。采用携带无启动子新霉素磷酸转移酶基因（nptI）的Mu dIIPR3转座子进行诱变，因此插入后，截短的基因可与菊欧文氏菌的启动子融合。在基本培养基平板上，选择在植物诱导基因中含有插入片段的突变体，因其对卡那霉素敏感；当将铁兰植物提取物添加到含卡那霉素的基本培养基平板上时，选择其对该抗生素获得性抗性。该筛选方法能够鉴定出被铁兰植物提取物中存在的宿主因子诱导的菊欧文氏菌启动子。利用该方法，我们分离出30个突变体，并对其中10个进行了表征。两个突变体在阳离子摄取方面存在缺陷，一个在半乳糖醛酸降解途径方面存在缺陷，另一个在酸性果胶裂解酶的产生方面发生了改变。其他突变基因的功能仍然未知，但我们表明它们中的大多数与致病性有关。
