Abstract: Citrus canker caused by the bacterium Xanthomonas citri subsp. citri (Xac) is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of Xac on host leaves. In this study, we assessed the hypothesis that small molecules able to inhibit biofilm formation reduce Xac infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by Xac on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative realtime reverse transcription polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in Xac. In laboratory experiments, planktonic and biofilm cells of Xac treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated.

Abstract: This application describes and claims a method of improving the health and vigor of a plant, comprising administering to the plant an effective amount of a bacterial composition which comprises a botanically compatible vehicle and an isolated bacterial strain selected from the group consisting of Bacillus megaterium PT6, Bacillus subtilis PT26A, Paenibacillus sp. ATY16, and any combination thereof. Improvement in health and vigor is one or more of the following: a) improved resistance to disease; b) improved ability to defend against disease; c) reduction of disease symptoms; d) faster growth; e) improved crop productivity; f) improved crop quality; g) improved seed germination; h) improved seedling emergence; or any combination thereof. Isolated bacterial strains and mixtures of bacteria are provided, as well as compositions comprising the isolated bacterial strains.

Abstract: This application describes and claims a method of improving the health and vigor of a plant, comprising administering to the plant an effective amount of a bacterial composition which comprises a botanically compatible vehicle and an isolated bacterial strain selected from the group consisting of Bacillus megaterium PT6, Bacillus subtilis PT26A, Paenibacillus sp. ATY16, and any combination thereof. Improvement in health and vigor is one or more of the following: a) improved resistance to disease; b) improved ability to defend against disease; c) reduction of disease symptoms; d) faster growth; e) improved crop productivity; f) improved crop quality; g) improved seed germination; h) improved seedling emergence; or any combination thereof. Isolated bacterial strains and mixtures of bacteria are provided, as well as compositions comprising the isolated bacterial strains.

Abstract: A method and compounds are described and claimed relating to plant defense inducer compositions and compounds, and to their use for improving certain aspects of plant and crop management, including treating plant disease, improving the ability of plants to defend against disease, reducing disease symptoms, treating HLB disease, minimizing crop yield decreases due to plant disease, improving crop productivity, and increasing crop quality. In particular, the compounds and compositions are useful for controlling and treating plant disease, for example Huanglongbing disease (HLB) and mitigating disease symptoms of HLB and Ca. Liberibacter infection in plants. Crop plants are contemplated for use with the invention, for example citrus trees.

Abstract: Citrus canker caused by the bacterium Xanthomonas citri subsp. citri (Xac) is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of Xac on host leaves. In this study, we assessed the hypothesis that small molecules able to inhibit biofilm formation reduce Xac infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by Xac on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative real time reverse transcription polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in Xac. In laboratory experiments, planktonic and biofilm cells of Xac treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated.