What are the plant traits and environmental factors driving the evolution of super nitrogen-fixer legumes?

• Grant number: 24/16735-4
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2025
• End date: January 31, 2030
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Agreement: Serrapilheira Institute
• Principal Investigator: Anselmo Nogueira
• Grantee: Anselmo Nogueira
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Santo André , SP, Brazil
• City of the host institution: Santo André
• Associated researchers: Alexandre Rizzo Zuntini ; Amanda Vieira da Silva ; Asmamaw Tesfaw Belay ; Caian Souza Gerolamo ; Célio Fernando Figueiredo Angolini ; Danilo da Cruz Centeno ; EDUARDO GROSS ; Eduardo Koerich Nery ; Euan Kevin James ; Flavia Fonseca Pezzini ; Italo Antonio Cotta Coutinho ; Joel Klein ; Juliana Gastaldello Rando ; Laura Carolina Leal de Sousa ; Luana de Souza Prochazka ; Rafaela Jorge Trad

Abstract

Nitrogen (N) is essential for life, with atmospheric N2 being converted into ammonia by root-nodulating bacteria in a process called biological nitrogen fixation (BNF), primarily associated with legumes. This nutrition mutualism occurs in belowground root nodules, enhancing the ecosystem's nitrogen availability and crop growth. However, the outcome of plant-rhizobia mutualisms varies spatially and temporally, influenced by environmental factors and partner traits commonly associated with facultative strategies in tropical regions. The mutualistic benefits depend on light, water, and soil nutrients, with mathematical models and empirical studies supporting that higher root nodulation is determined by higher light and lower soil nitrogen availabilities. Understanding these dynamics on ecological and evolutionary scales is crucial for predicting optimal partnerships and conditions. However, knowledge gaps on the importance of mutualism to plants and associated functional traits hinder these studies. To address these gaps, we aim to investigate the evolution of nitrogen-fixing legumes, focusing on environmental niches and plant traits' impact on BNF efficiency. We'll use the Chamaecrista lineage (Leguminosae) as a plant model to study plant- rhizobia interaction and BNF evolution. The project involves building a database of legume functional traits linked to the BNF in Cerrado, studying the phenotypic evolution of nitrogen fixation in the species-rich genus Chamaecrista, and conducting experiments with rhizobia strains from these native legume species. We hypothesize that certain legume lineages evolved enhanced nitrogen-fixing capacity linked to specific traits and environmental conditions. Understanding these dynamics will aid in identifying exceptional nitrogen fixers and accessing genetic resources for soil enrichment and ecosystem management, especially in the Cerrado. (AU)