ANALYSIS OF THE POTENTIAL FOR TARGETED HOST SPECIFICITY IN BACTERIAL PLANT-INOCULANTS

PLANT AND SOIL HEALTH CAN BE IMPROVED THROUGH THE INOCULATION OF PLANT ROOTS WITH BENEFICIAL BACTERIA. IN PARTICULAR, BACTERIAL INOCULANTS THAT CONTROL FUNGAL DISEASE OF PLANT ROOTS HAVE PROVEN SUCCESSFUL UNDER LIMITED SETS OF CONTROLLED CONDITIONS. HOWEVER, THE POTENTIAL OF THESE INOCULANTS HAS YET TO BE REALIZED UNDER FIELD CONDITIONS. ONE REASON FOR THIS IS THAT INDIVIDUAL BACTERIAL PRODUCTS ARE LIMITED IN THEIR RANGE OF APPLICABILITY DUE IN PART TO LIMITATIONS ON RHIZOSPHERE POPULATIONS FOR DIFFERENT CROPS AND UNDER DIFFERENT ENVIRONMENTAL CONDITIONS. THIS PROPOSAL IS DIRECTED TOWARDSTHE ISOLATION OF GENES THAT WOULD EXPAND THE APPLICABILITY OF SPECIFIC FLUORESCENT PSEUDOMONAD BILOGICAL CONTROL AGENTSBY IMPROVING RHIZOSPHERE COMPETENCE ON DIFFERENT CROP PLANTS. IT SHOULD ALSO LEAD TO THE ISOLATION OF GENES THAT WOULD CONTROL RHIZOSPHERE COMPETENCE IN COMMON PATHWAYS. THE RESEARCH GOALS ARE TO ASSEMBLE A WELL-CHARACTERIZED COLLECTION OF FLUORESCENT PSEUDOMONADS THAT ARE AMENABLE TO MOLECULAR GENETIC ANALYSIS, AND THEN TO EVALUATE WHETHER RHIZOSPHERE COMPETENCE OF THESE STRAINS IS HOST-SPECIFIC FORTHREE DIFFERENT CROP PLANTS. THE TECHNICAL APPROACH DEVELOPED IN PHASE I RESEARCH WILL ESTABLISH APPROPRIATE ASSAYS FOR THE ISOLATION OF RHIZOSPHERE COMPETENCE GENES.