A novel actin-related protein gene of Colletotrichum gloeosporioides f. spmalvae shows altered expression corresponding with spore production

A novel actin-related protein (arp) was found in the plant pathogenic fungu s. Colletotrichum gloeosporioides f. sp. malvae (Cgm), which causes anthrac nose disease of round-leaved mallow (malva pusilla), Sequence comparisons s howed that this gene, arpA. belongs to the highly divergent 'other arps' ca tegory in the current arp classification system. ArpA is most similar to th e arp11 gene of Mus musculus but has a unique structure with deletions at t he C-terminus similar to that of the arp10 gene of Saccharomyces cerevisiae . A portion of another putative arp gene, arpB, was found immediately downs tream of arpA. Expression of arpA was compared to the constitutively expres sed Cgm actin gene, actA, in culture, the relative expression of arpA incre ased when growth conditions favored sporulation. During infection, arpA exp ression was greatest at the late necrotrophic phase, when sporulation occur red. Arps have been shown to be important in nuclear migration in Fungal hy phae, and the expression pattern of arpA indicates that it may have a parti cular role during sporulation. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.