S152: Bacillus subtilis strain QST713: A microbe with two tales

SERENADE® is the most widely used foliar biofungicide in the world, with registrations in 23 countries.  Its active ingredient, Bacillus subtilis QST713, is a unique, genetically distinct, patented strain originally isolated from soil. QST713 is distinguished from other Bacillus strains by its high production of a diverse set of antifungal lipopeptides that work synergistically to control fungal pathogens. In addition, QST713 produces a range of other antifungal and antibacterial compounds and stimulates plant systemic resistance and overall growth. Beyond its well documented activity as a foliar fungicide, our research has shown that QST713 is also active in the rhizosphere, enhancing host plant growth when applied as a soil drench or seed treatment while controlling soil diseases. We demonstrate here that QST713 colonizes seeds and root surfaces, forming multicellular communities in the rhizosphere of plants. In addition, we show that QST713 directly inhibits soil pathogens and indirectly induces systemic resistance and plant growth by the production of volatile compounds.