Exploring the roles of extracellular microRNAs in plant development and in interactions with the rhizosphere microbiome

• Grant number: 25/00622-9
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2025
• End date: June 30, 2028
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Fabio Tebaldi Silveira Nogueira
• Grantee: Fabio Tebaldi Silveira Nogueira
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated researchers: Paulo José Pereira Lima Teixeira

Abstract

Extracellular small RNAs (sRNAs) have emerged as important molecules mediating inter-organismal interactions, including plant-to-plant communication and interactions between plants and microorganisms. However, which extracellular sRNAs and how they mediate these interactions and influence plant development remain poorly understood. Therefore, this study aims to answer two questions: (1) Can extracellular microRNAs (miRNAs) modulate plant development? (2) Can extracellular sRNAs (including miRNAs) modulate and be modulated by the rhizosphere microbiome during plant development? For Question (1), we will examine whether extracellular miRNAs and miRNA-overexpressing plant-derived extracts can modulate Arabidopsis thaliana and tomato (Solanum lycopersicum) early development. To address Question (2), we will investigate the transcriptomic landscape of sRNAs in Arabidopsis roots colonized by a model synthetic community comprised of 35 members (SynCom35), and examine the taxonomic profiles of the inhabiting SynCom35 in Arabidopsis roots during the transition from juvenile to adult stages in distinct genotypes. We will also exogenously apply sRNAs/miRNAs directly to plants and to the SynCom35 bacterial consortium to understand their roles in root development and the composition of bacterial communities in the rhizosphere. Finally, this study will examine how bacterial colonization affects root architecture in these plants by modulating miRNA expression. For each of the research areas, we intend to employ molecular biology, developmental genetics, imaging, next generation sequencing (NGS), and bioinformatics tools. Moreover, we use Arabidopsis and tomato in our studies as each model organism offers unique experimental advantages and because comparative studies can provide an evolutionary perspective on key genetic pathways associated with inter-organismal interactions. (AU)