Role of cutinase and cell wall degrading enzymes in infection of pisum sativum by fusarium solani f sp pisi
Koller, W.; Allan, C.R.; Kolattukudy, P.E.
Physiological Plant Pathology 20(1): 47-60
Virulence of several isolates of F. solani f. sp. pisi (Nectria haematococca) was measured by bioassays using pea stems with or without intact cuticular and cell wall barriers. Isolate T-8 was highly virulent in both assays whereas isolate T-30, which was almost avirulent on the intact surface, was highly virulent only on wounded stems. With a highly sensitive radioassay for cutinase the germinating spores of T-8 were shown to release this enzyme which was similar, if not identical to, that produced during saprophytic growth on cutin. The amount of cutinase released by germinating spores of Fusarium isolates correlated with the degree of virulence expressed on intact surfaces. The low virulence of T-30 shown on stems possessing intact cuticles and cell walls was increased to the level expressed on wounded stems by addition of cutinase, pectinesterase, pectinase and cellulase. These results strongly suggest that the level of cutinase and cell wall degrading enzymes produced by germinating spores can determine the efficiency of infection.