Unraveling the role of secretion systems (T1SS and T5aSS) of Pantoea agglomerans 33.1 in plant growth promotion and modulation of associated microbiota

• Grant number: 24/15562-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2025
• End date: September 30, 2026
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Maria Carolina Quecine Verdi
• Grantee: Gabriel Valverde Firmino
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated scholarship(s): 25/06990-0 - Unraveling the role of secretion systems of Pantoea agglomerans 33.1 in plant-growth promotion and modulation of associated microbiota, BE.EP.MS

Abstract

Bacteria use different strategies to ensure their own survival and colonize different environments and hosts, using Protein Secretion Systems (SSPs) to transport molecules and interact with the environment and other organisms. Pantoea agglomerans is a cosmopolitan Gram-negative bacterium that exhibits a wide metabolic diversity. This diversity is reflected in the various environments and hosts where it can be found: plants, soils, animals, and water. In general, P. agglomerans has been described as beneficial to various plants, promoting plant growth and controlling phytopathogens. However, some pathovars are causal agents of diseases in certain crops, highlighting the complexity in classifying and understanding the molecular biology of this species. For example, the strain P. agglomerans 33.1, endophytically isolated from Eucalyptus grandis, has demonstrated proven plant growth promotion in various crops. The P. agglomerans 33.1 had its complete genome sequenced, and in addition to obtaining a portfolio of genes related to plant growth promotion (such as auxin-related genes and phosphate solubilization genes), it was found to have complete set of genes encoding to T1SS and T5aSS secretion systems. The actual role of these secretion systems in the fitness and plant growth promotion by beneficial bacteria is still in its early stages of discovery. Therefore, the objective of this project is the knockout of bepC (from T1SS) and prn (from T5aSS) genes in order to evaluate the role of secretion systems in P. agglomerans 33.1. Subsequent analysis of the secretome, as well as inoculation of the wild-type and mutant strains on sugarcane rhizosphere will assess their impact on plant growth, nutrition, and the associated microbiota. The results obtained in this study will contribute to understanding the biology of this strain as a plant growth promoter, as well as the relevance of BSSs in P. agglomerans 33.1 in its interaction with the host plant and soil microbiota.