CHARACTERIZATION OF TRANSPOSON INSERTION OUT- MUTANTS OF ERWINIA-CAROTOVORA SUBSP CAROTOVORA DEFECTIVE IN ENZYME EXPORT AND OF A DNA SEGMENT THAT COMPLEMENTS OUT MUTATIONS IN ERWINIA-CAROTOVORA SUBSP CAROTOVORA, ERWINIA-CAROTOVORA SUBSP ATROSEPTICA, AND ERWINIA-CHRYSANTHEMI

被引:55
作者
MURATA, H
FONS, M
CHATTERJEE, A
COLLMER, A
CHATTERJEE, AK
机构
[1] UNIV MISSOURI, DEPT PLANT PATHOL, 108 WATERS HALL, COLUMBIA, MO 65211 USA
[2] CORNELL UNIV, DEPT PLANT PATHOL, ITHACA, NY 14853 USA
关键词
D O I
10.1128/jb.172.6.2970-2978.1990
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
Soft-rotting Erwinia spp. export degradative enzymes to the cell exterior (Out+), a process contributing to their ability to macerate plant tissues. Transposon (Tn5, Tn10, Tn10-lacZ) insertion Out- mutants were obtained in Erwina cartovora subsp. carotovora 71 by using plasmid and bacteriophage lambda delivery systems. In these mutants, pectate lysases, polygalacturonase, and cellulase, which are normally excreted into the growth medium, accumulated in the periplasm. However, localization of the extracellular protease was not affected. The Out- mutants were impaired in their ability to macerate potato tuber tissue. Out+ clones were identified in a cosmid library of E. carotovora subsp. carotovora 71 by their ability to complement mutants. Localization of cyclic phosphodiesterase in the periplasm indicated that the Out+ plasmids did not cause lysis or a nonspecific protein release. The Out+ derivatives of the E. carotovora subsp. carotovora 71 mutants regained the ability to macerate potato tuber tissue. Our data indicate that a cluster of several genes is required for the Out+ phenotype. While one plasmid, pAKC260, restored the Out+ phenotype in each of the 31 mutants of E. carotovora subsp. carotovora, E. carotovora subsp. atroseptica, and Erwinia chrysanthemi, it failed to render Escherichia coli export proficient. Homologs of E. carotovora subsp. carotovora 71 out DNA were detected by Southern hybridizations in subspecies of E. carotovora under high-stringency conditions. In contrast, E. chrysanthemi sequences bearing homology to the E. carotovora subsp. carotovora 71 out DNA were detectable only under low-stringency hybridization. Thus, although the out genes are functional in these two soft-rotting bacterial groups, the genes appear to have diverged.
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页码:2970 / 2978
页数:9
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