The rhizosphere is the critical interface for initiating both beneficial and harmful interactions between plants and microbes and it has become apparent that plants use root exudates to manipulate these interactions. This project will investigate root-secreted signals that serve as specific chemoattractants for Bacillus subtilis in the rhizosphere. The genus Bacillus has great potential use in agriculture, as its members are able to synthesize antimicrobial metabolites to ward off plant pathogens. While plant-associated bacterial chemical signals have been identified as activators of plant defences, plant metabolites that elicit rhizobacterial responses have yet to be characterized. The biochemical and genetic links identified and techniques developed in the course of this project should uncover new aspects of rhizosphere interactions and form a foundation for the further development of our understanding of both symbiotic and non-symbiotic plant-microbe associations. An outreach component will enrich the STEM (Science Technology Engineering and Mathematics) initiative in the Christina School District. A collaboration with science facilitators at Glasgow High School to strengthen the ecology components in the K-12 Delaware statewide recommended curricula, by creating an interactive environment between the classroom and the laboratory for K-12 students and science teachers.
The rhizosphere is the critical interface for initiating both beneficial and harmful interactions between plants and microbes and it has become apparent that plants use root exudates to manipulate these interactions. This project investigated the root-secreted signals that serve as specific chemo-attractants for Bacillus subtilis in the rhizosphere. The genus Bacillus has great potential use in agriculture, as its members are able to synthesize antimicrobial metabolites to ward off plant pathogens. While plant-associated bacterial chemical signals have been identified as activators of plant defenses, plant metabolites that elicit rhizobacterial responses have yet to be characterized. Through this project, we investigated the biological importance of beneficial plant microbe interactions in disease protection. Our work showed that plants under aerial stress may associate more with the beneficial rhizobacteria in the rhizosphere. The intraplant signal discovered through our work showed that plants attempt to send a SOS message under pathogen attack to associate with beneficial microbes. In turn, beneficial rhizobacteria induces systemic resistance in plants against foliar pathogens. The biochemical and genetic links identified and techniques developed in the course of this project may help uncover new aspects of rhizosphere interactions and form a foundation for the further development of our understanding of both symbiotic and non-symbiotic plant-microbe associations.
