The Major Secreted Cellulase, CelV, of Erwinia carotovora subsp, carotovora Is an Important Soft Rot Virulence Factor. Denise S. Walker. Department of Biological Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom. Philip J. Reeves, and George P. C. Salmond. Department of Biological Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom. MPMI 7:425-431. Accepted 14 February 1994. Copyright 1994 The American Phytopathological Society.

CelV is the major secreted (ß-1,4-endoglucanase of the phytopathogen Erwinia carotovora subsp, carotovora. Its role in virulence was investigated by comparing the ability of a cellulasc-deficient mutant to cause soft rot of potato tubers with that of the wild type. A significant role was demonstrated despite the inability of CelV to effect soft rot when expressed in Escherichia coli. This established the major Cellulase of E. carotovora subsp, carotovora as a virulence factor and provided evidence for a synergistic relationship between the various classes of exoenzyme in attack of potato tubers.