Identification of antifungal proteins associated to aspergillus resistance infection in peanut seed

MULLER V; GIECO J; BONACCI G; CARRARI F; ASIS R

San Luis

Encuentro; XLVII Reunion Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011

Aspergillus flavus and parasiticus are aflatoxigenics fungi thatinfect peanut seeds both under field conditions and post harveststorage. We have previously found a significant associationbetween aflatoxin contamination and fungal infection. Therefore,in order to identify the components that contribute to Aspergillusresistance the present work investigate the proteins involved in thedefense response to infection in peanut seed. The pathosystem usedin our approach is composed by two genotypes: PI337394 andFlorman previously characterized as resistant and susceptible toAspergillus infection and aflatoxin contamination. Seeds of bothgenotypes were disinfected and inoculated with A. parasiticus andproteins extract with antifungal activity were enriched bychromatography. Elution fractions with antifungal activity wereanalyzed by 2D-eletrophoresis and identified by HPLC-ESI-MS.Proteins with known antifungal activity such as quitinases andpathogenesis related proteins, and proteins that participate in plantdefense such as superoxide dismutases, lectins and alergens werefound overrepresented in 2D-electrophoresis gels from the resistantcultivar. These results suggest that antifungal proteins play animportant role in the defense response to A. parasiticus infection inresistant peanut seed.