ROLE OF ENDOGLUCANASES IN ERWINIA-CHRYSANTHEMI-3937 VIRULENCE ON SAINTPAULIA-IONANTHA

The role of endoglucanases (endoglucanases Z and Y) in Erwinia chrysan themi pathogenicity on Saintpaulia ionantha was assessed by mutagenizi ng cloned eel genes (celZ and celY) and recombining them with the chro mosomal alleles. Strains with an Omega interposon in celZ, a deletion in celY, or a double eel mutant were as virulent as the wild-type stra in. However, in the strain with a deletion in celY, a delay in the app earance of symptoms was observed, and then maceration progressed as in plants infected with the wild-type strain, suggesting that E. chrysan themi endoglucanases play a minor role in soft rot disease development .