Auxotrophic enrichment in the rhizosphere: Unraveling bacterial responses to plant exudates in the context of nutrient limitation

• Grant number: 25/07364-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2025
• End date: September 30, 2026
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Simone Raposo Cotta
• Grantee: Duber Alejandro Mora Motta
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 24/16079-0 - Auxotrophic enrichment in the rhizosphere: Unraveling bacterial responses to plant exudates in the context of nutrient limitation, AP.R

Abstract

Plants influence the bacterial community in rhizospheric soil by releasing compounds such as amino acids, which act as nutrients or signaling molecules. This can promote the selection of auxotrophic bacteria unable to synthesize these compounds. We propose that these auxotrophs are enriched in the rhizosphere due to the availability of amino acids and that these organisms could help plants overcome nutritional stress. To test this hypothesis, we will employ a polyphasic approach that combines dependent and independent cultivation methodologies to assess the bacterial community, evaluate their auxotrophic profiles, and examine the consequences of these organisms' presence under both control conditions and nutritional deficiency. Phosphorus will be used as the model nutrient. Additionally, we will analyze plant-derived metabolites, such as amino acids and vitamins, to understand their role in shaping bacterial communities. These experiments aim to elucidate the prevalence of auxotrophic bacteria in the rhizosphere and their impact on plant resilience and resistance under nutritional stress. (AU)