Function and Regulation of Pectin-Degrading Enzymes in Bacterial Wilt Disease
Virulence assays with various mutant strains indicate that extracellular polygalacturonases (PGs) contribute additively to bacterial wilt disease. However, pectinmethylesterase is not required for wild type virulence, at least on eggplants. Reaction product analysis shows that one PG, PehB, is an exo-poly-a-Dgalacturonosidase; further, the regulatory pehSR locus is required for wild type pehB expression. Genetic and biochemical evidence indicates that PehR is a response regulator of endo-polygalacturonase gene expression. In addition, the pehSR locus also regulates motility by a mechanism that is not yet understood.
KeywordsSugar Agar Polysaccharide Pseudomonas Microbe
Unable to display preview. Download preview PDF.
- Allen C, Gay J, Simon, L (in press) PehSR, a positive regulator of polygalacturonase production and other virulence factors in Ralstonia solanacearum. Mol Plant-Microbe InteractGoogle Scholar
- Clough SJ, Flavier AB, Schell MA, Denny TP (1997) Differential expression of virulence genes and motility in Ralstonia (Pseudomonas) solanacearum during exponential growth. App and Env Microbiol 63(3):844 – 850Google Scholar
- Huang Q Allen C (in press) An exo-poly-a-D-galacturonosidase, PehB, is required for wild type virulence in Ralstonia solanacearum. J BacteriolGoogle Scholar