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Environmental conditions affect transcription of the pectinase genes of Erwinia chrysanthemi 3937
- Publication Year :
- 1992
-
Abstract
- To depolymerize plant pectin, the phytopathogenic enterobacterium Erwinia chrysanthemi produces a series of enzymes which include a pectin-methyl-esterase encoded by the pem gene and five isoenzymes of pectate lyases encoded by the five genes pelA, pelB, pelC, pelD, and pelE. We have constructed transcriptional fusions between the pectinase gene promoters and the uidA gene, encoding beta-glucuronidase, to study the regulation of these E. chrysanthemi pectinase genes individually. The transcription of the pectinase genes is dependent on many environmental conditions. All the fusions were induced by pectic catabolic products and responded, to different degrees, to growth phase, catabolite repression, temperature, and nitrogen starvation. Transcription of pelA, pelD, and pelE was also increased in anaerobic growth conditions. High osmolarity of the culture medium increased expression of pelE but decreased that of pelD; the other pectinase genes were not affected. The level of expression of each gene was different. Transcription of pelA was very low under all growth conditions. The expression of the pelB, pelC, and pem genes was intermediate. The pelE gene had a high basal level of expression. Expression of pelD was generally the most affected by changes in culture conditions and showed a low basal level but very high induced levels. These differences in the expression of the pectinase genes of E. chrysanthemi 3937 presumably reflect their role during infection of plants, because the degradation of pectic polymers of the plant cell walls is the main determinant of tissue maceration caused by soft rot erwiniae.
- Subjects :
- Transcription, Genetic
Nitrogen
Recombinant Fusion Proteins
Molecular Sequence Data
Pectobacterium chrysanthemi
Catabolite repression
Erwinia
Microbiology
Isozyme
Transcription (biology)
Anaerobiosis
Pectinase
Molecular Biology
Gene
Glucuronidase
Polysaccharide-Lyases
biology
Osmolar Concentration
Temperature
Promoter
Gene Expression Regulation, Bacterial
biology.organism_classification
Repressor Proteins
Biodegradation, Environmental
Polygalacturonase
Biochemistry
Carbohydrate Sequence
Genes, Bacterial
Pectins
Enzyme Repression
Carboxylic Ester Hydrolases
Research Article
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....054428a7fdf895bd91eab26ca4fbe283