INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Interacción de hongos patógenos y su huésped: Aspectos bioquímicos y moleculares.
Autor/es:
JUÁREZ M. PATRICIA
Reunión:
Congreso; X Congreso Argentino de Microbiologia General. SAMIGE; 2014
Resumen:
Sección: Conferencias Plenarias Modalidad: Oral INTERACCIÓN DE HONGOS PATÓGENOS Y SU HUÉSPED: ASPECTOS BIOQUÍMICOS Y MOLECULARES INTERACTIONS BETWEEN PATHOGENIC FUNGI AND THEIR HOSTS. BIOCHEMICAL AND MOLECULAR FEATURES M. Patricia Juárez1 1 Instituto de Investigaciones Bioquímicas de La Plata (CCT La Plata CONICET-UNLP), Facultad de Cienc. mjuarez@isis.unlp.edu.ar Both animal and plant pathogenic fungi that reside in soils and vegetation must withstand major environmental challenges. Hence, many of the virulence factors appear to allow survival in the environment and establishment in the host. Entomopathogenic fungi mostly attack their insect hosts by penetrating through the cuticle, covered by a lipid-rich layer, usually containing large amounts of very long-chain hydrocarbons, that are essential to prevent lethal desiccation in the insect. Here we will review how the hydrocarbon barrier can be efficiently used as carbon source for fungal growth. An initial hydroxylation step by a microsomal P450 monooxigenase system, followed by successive transformations, will eventually provide the appropriate fatty acyl-CoAs for complete degradation in the peroxisomes, the site of β-oxidation in fungi. Concurrently, an oxidative stress scenario is established to counter this situation. After the cuticle is breached, the fungi reach the internal cavity rich in more easily available substrates; thus, a correlation between fungal ability to catabolize hydrocarbons and virulence can be established. Among plan pathogenic fungi, the genus Fusarium is one of the most important genera affecting cereal crops in many areas of the world. Many Fusarium species are usual pathogens of wheat and barley; one of the most serious diseases produced is Fusarium head blight (FHB). Infection can affect the quantity, quality, and marketability of the grain and contaminate the grains with trichothecenes and other mycotoxins. Both during primary and secondary metabolism, fungi produce volatile organic compounds (VOC), intermediate and end products of various metabolic pathways; some of them can be used for their detection and identification. Trichodiene is the volatile precursor of deoxynivalenol, the most toxigenic trichotecene mycotoxin released by Fusarium graminearum. We will review the utility of solid phase microextraction (SPME) coupled to capillary gas chromatography (CGC) and mass spectrometry (MS) to differentiate trichotecene-producer and non-trichotecene producer Fusarium spp. We will further show the utility of these techniques on the early detection of F. graminearum in wheat cultivars, before FHB development.