Bacterial Metabolism of Propagule Germination Stimulants as an Important Trait in the Biocontrol of Pythium Seed Infections
Seed and root exudates are the major driving force behind the spermosphere and rhizosphere activities of soilborne plant pathogens as well as those of associated microorganisms. Stimulatory compounds present in seed exudates alleviate fungistasis, allowing host-pathogen interactions in soil to be initiated. They also support the growth and activities of spermosphere and rhizosphere microorganisms. Since the majority of host-parasite interactions in soil do not occur without the release of such stimuli (Curl and Truelove, 1986; Nelson, 1990), an understanding of the exudate molecules involved in the activation of quiescent fungal propagules is of prime importance in understanding the initiation and control of seed and root infections by soilborne pathogens. Perhaps more importantly to our understanding of the biological control of seed and root infections is the ability of other microorganisms to interfere with the production and activity of these stimulatory molecules.
KeywordsStimulatory Activity Enterobacter Cloaca Soilborne Pathogen Pythium Species Unsterilized Soil
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