Unraveling the role of secretion systems of Pantoea agglomerans 33.1 in plant-growth promotion and modulation of associated microbiota

• Grant number: 25/06990-0
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: August 15, 2025
• End date: February 14, 2026
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Maria Carolina Quecine Verdi
• Grantee: Gabriel Valverde Firmino
• Supervisor: Connor Fitzpatrick
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: University of Calgary, Canada
• Associated to the scholarship: 24/15562-9 - Unraveling the role of secretion systems (T1SS and T5aSS) of Pantoea agglomerans 33.1 in plant growth promotion and modulation of associated microbiota, BP.MS

Abstract

Bacteria utilize Secretion Systems (BSSs) to transport proteins and interact with the environment, with other bacteria, or with even other eukaryotic organisms. Pantoea agglomerans is a cosmopolitan Gram-negative bacterium that exhibits a wide metabolic diversity. Some strains of P. agglomerans have been described as beneficial to various plants, promoting the plant growth and controlling diverse phytopathogens. P. agglomerans strain 33.1 was endophytically isolated from Eucalyptus grandis. It has been demonstrated to be able to promote the plant growth of various crops. Although, little is known about the role of its SSs during plant interaction, in which the strain can solubilize phosphate, fix nitrogen and induce the production of phytohormones. After obtaining the complete genome of P. agglomerans 33.1, important genes responsible for structural proteins in the T1SS and T5SS were located. Therefore, the unique genes bepC (from T1SS) and prn (from T5aSS) were knocked out in order to evaluate the role of secretion systems in P. agglomerans 33.1. T1SS and T5aSS were chosen due to being the SSs with all genes found in P. agglomerans 33.1 genome. The mutants were obtained recently, and for further steps it is important to 1) analyze the protein content secreted in the interaction between the bacterium and plants, as well as 2) analyze the impact that this bacterium can have in the composition of the rhizosphere microbiome. This research internship aims to advance the understanding of plant-microbe interactions by conducting proteomic and metataxonomic analyses of P. agglomerans 33.1 and its interaction with sugarcane (Saccharum sp.) and the model plant Arabidopsis thaliana. Here, we propose an international intership project associated with FAPESP Process Nº 2024/15562-9 that will focus on characterizing the bacterial secretome of the P. agglomerans 33.1 mutants and evaluating its influence on the soil microbiota. These analyses represent the final phases of the candidate's Master's research at the University of São Paulo (USP) and require specialized expertise and infrastructure available at the University of Calgary under the supervision of Dr. Connor Fitzpatrick. The outcomes of this study will contribute to the broader field of sustainable agriculture by elucidating the effects of bacterial secretion on plant health and soil microbial diversity. (AU)