Abstract

RODRIGUEZ-LOPEZ, Edgar Saúl; GONZALEZ-PRIETO, Juan Manuel  and  MAYEK-PEREZ, Netzahualcoyotl. Infection of avocado (Persea americana Mill.) by Colletotrichum gloeosporioides (Penz.) Penz. y Sacc.: Biochemical and genetics aspects. Rev. mex. fitopatol [online]. 2009, vol.27, n.1, pp.53-63. ISSN 2007-8080.

The fungus Colletotrichum gloeosporioides is the causal agent of anthracnose in avocado (Persea americana), disease which causes production losses near 20%. Fungal infection starts after recognition of fatty alcohols and waxes at the fruit surface, and two hours later CgMEKx and CgMEK1 genes are phosphorylated. These genes are involved in differentiation and conidia germination as well as appresorium formation. In addition, proteins CHIP2 and CHIP3, related with fruit surface contact, are secreted. Activation of gene cap20 helps the apressorium to develop after infective hyphae are produced, to provide pressure and secrete cell-wall degrading enzymes. Changes in host pH activate pac1 gene which induces pelB gene expression and then polygalacturonase and pectate-lyase enzymes are produced. Avocado fruits produce diene an reactive-oxygen species. These compounds provoke fungal quiescence until their levels decrease as well fruit ripens. The biotrophic infective process produces secretion of CIH1 protein, and the necrothrophy stage involves proteins CLTA1 and CgDN3, which are related with tissue necrosis at a later stage.

Keywords : Anthracnose; transduction signals.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )