Pseudomonas and other Microbes in Disease-Suppressive Soils
Résumé
Soil-borne phytopathogens cause extensive damage to cultivated plants worldwide, resulting in yield loss worth billions of Euros each year. Soil fumigation is the most effective chemical treatment but is too expensive for many crops, and fumigants like methyl bromide are being phased out for environmental reasons. In this context, much is to be learned from disease-suppressive soils, where susceptible plants are protected from soil-borne pathogens by the indigenous microbiota, because these microbial interactions may be exploited to design sustainable crop protection strategies for ordinary farm soils. However, our knowledge of plant-protecting microorganisms and biocontrol mechanisms involved in soil suppressiveness remain very fragmented, as most knowledge on disease suppressive soils comes from studies restricted to individual plant-protecting microbial populations, mostly fluorescent Pseudomonas species. The phenomenon of disease suppressiveness remains therefore poorly understood, even in the most studied cases such as suppressiveness to wheat take-all.