Identifying Macrophomina phaseolina genes involved in phytotoxin phaseolinone production using cDNA-AFLP analysis
N. AZARMANESH (1), M. Saini (1), J. Bond (1), A. M. Fakhoury (1)
(1) Southern Illinois University Carbondale, Carbondale, IL, U.S.A.
Phytopathology 101:S11

Macrophomina phaseolina is a soil and seed-borne pathogen that causes charcoal rot in soybean. Charcoal rot is one of the most destructive diseases of soybean in the United States. Little is known about the mechanisms governing the interaction between soybeans and M. phaseolina that result in charcoal rot development. The ability of M. phaseolina to cause charcoal rot may be associated with the production of the phytotoxin phaseolinone by the fungus. A cDNA-AFLP (Amplified Fragment Length Polymorphism) approach was used as a qualitative and quantitative tool to identify M. phaseolina genes involved in the production of phaseolinone. M. phaseolina was grown in conditions conducive and non-conducive to the production of the phytotoxin. The cDNA AFLP screen was conducted using nine MseI/EcoRI AFLP primer combinations. Sixty four unique transcript-derived fragments (TDFs) were found to be differentially expressed across the different growing conditions. The expression patterns of the corresponding genes were confirmed by quantitative Real Time PCR. This is the first report of M. phaseolina genes potentially involved in the biosynthesis of phaseolinone. These findings can be used to develop new tools to study the interaction between soybean and M. phaseolina.