John Innes Institute, Colney Lane, Norwich NR4 7UH, UK.
EMBO J. 1984 Dec 20;3(13):3323-8. doi: 10.1002/j.1460-2075.1984.tb02298.x.
A genomic library was prepared in Escherichia coli from DNA of wild-type Xanthomonas campestris pv. campestris (aetiological agent of crucifer black rot), partially digested with endonuclease EcoRI, using the mobilisable broad host range cosmid vector pLAFR1. Recombinant plasmids contained inserts ranging in size from 19.1 to 32.3 kb (mean 26.6). Certain of the clones complemented E. coli auxotrophic markers. Using the narrow host range plasmid pRK2013 as a helper the pooled recombinant plasmids were transferred conjugally to X. c. campestris mutants, and clones were identified which restored yellow pigmentation to white mutants, prototrophy to amino acid auxotrophs and pathogenicity towards turnip plants to two non-pathogenic mutants. The lesion in one mutant (8288, complemented by the plasmid pIJ3000) is unknown. However mutant 8237 is defective in production of extracellular protease and polygalacturonate lyase and restoration of pathogenicity by complementation with the plasmid pIJ3020 concomitantly restored both enzyme levels to wild-type values.
从野生型野油菜黄单胞菌 pv. 野油菜（十字花科黑腐病的病原体）的 DNA 中，用内切酶 EcoRI 部分消化，在可移动的广泛宿主范围质体 pLAFR1 中制备了大肠杆菌的基因组文库。重组质粒的插入片段大小从 19.1 到 32.3kb（平均值为 26.6）不等。某些克隆能够补充大肠杆菌营养缺陷型标记。使用窄宿主范围质粒 pRK2013 作为辅助物，将混合的重组质粒通过共轭转移到野油菜黄单胞菌突变体中，并鉴定出了能够使白色突变体恢复黄色色素、使氨基酸营养缺陷型恢复营养能力以及使两种非致病性突变体恢复对萝卜植物致病性的克隆。一个突变体（8288，由质粒 pIJ3000 互补）的病变尚不清楚。然而，突变体 8237 缺乏细胞外蛋白酶和多聚半乳糖醛酸裂解酶的产生，并且用质粒 pIJ3020 进行互补恢复了致病性，同时将两种酶的水平恢复到野生型值。
