High expression of a sucrose non-fermenting (SNF1)-related protein kinase from Colletotrichum gloeosporoides f. sp malvae is associated with penetration of Malva pusilla

A sucrose non-fermenting (SNF1)-related protein kinase homologue, cgsnf, from Collelotrichum gloeosporoides f. sp. malvae, a hemibiotrophic fungal pathogen of round-leaved mallow (Malva pusilla) was examined. During infection, cgsnf showed a large peak in expression relative to a constitutively expressed fungal actin gene when appressoria had formed during the penetration phase and then showed much lower expression levels during subsequent necrotrophic growth in the host. In pure culture with glucose or glycerol as sole carbon sources, expression levels were similar to that during necrotrophic growth. Expression was consistently higher in glycerol than in glucose cultures, which may reflect a lower cellular energy status in the fungus. These results Lire consistent with cgsf having a role in transmitting nutritional signals, which may be involved with host penetration. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.