Title: Molecular Interaction between plant growth promoting rhizobacteria
(Burkholderia phytofirmans strain PsJN) and Vitis vinifera plants
When rhizobacteria are introduced to control soil-borne root diseases, they must establish metabolically active populations that mediate protection either by direct antagonism of pathogens or indirectly by stimulation of host plant defenses. Most mechanisms proposed to explain indirect growth promotion suggest that the active principle may be a secondary bacterial metabolite that antagonizes pathogens.
Recently, induced resistance to diseases, or plant “immunization,” has received increasing attention. This refers to a process in which plants exhibit an increased level of resistance to infection by a pathogen after appropriate stimulation. Indeed, plants can acquire enhanced resistance to pathogens after treatment with necrotizing attackers or non-pathogenic micro-organisms. The induced resistance is often associated with an enhanced capacity to mobilize infection-induced cellular defence responses. This process is known as priming. B. phytofirmans strain PsJN can efficiently colonize various plants as rhizosphere microbe as well as endophyte and has shown beneficial effects on plant growth and plant health. In grapevine, we recently described that this bacterium can form epi- and endophytic subpopulations under gnotobiotic conditions as well using natural soil systems. A previous study also reports that under gnotobiotic conditions strain PsJN leads to an enhanced tolerance of grapevine towards Botrytis cinerea, the causing agent of gray mould disease. These results indicate that this strain induces systemic resistance responses in grapevine. However, their associated mechanisms have not been investigated. First investigation during interaction between Fruiting cuttings of Vitis vinifera L. and the endophyte Burkholderia phytofirmans strain PsJN has reported that PR-encoding genes analyses suggest an SA dependent pathway in (...)