Identification of defence proteins from the seed exudates ofCicer arietinumL. and its effect on the growth ofFusarium oxysporumf.sp.ciceri

Germinating seeds tend to release a variety of proteins into their surrounding surfaces; some of which have an inhibitory action against plant pathogens. The aim of this study was to investigate and identify defence proteins present in the exudates from water-imbibed and chitosan-imbibed (0.1% w/v) seeds of chickpea (Cicer arietinum L). Chickpea seeds imbibed in chitosan released a higher amount of proteins in the exudate when compared to the seeds imbibed in water. The obtained exudates were analysed in regard to specific protein activities by enzymatic assays and SDS-PAGE analysis. Results showed that the exude obtained from chickpea seeds imbibed in chitosan solution exhibited a new isoform of chitinase, chitosanase and protease inhibitors. These exudates also have an “in vitro” inhibitory effect on the growth of the fungus, Fusarium oxysporum f.sp. ciceri. Our results suggest that seed exudates protect seeds during their germination from soil pathogens.