The use of plant growth-promoting bacteria Bacillus megaterium and Bacillus subtilis as potential softeners of the allelopathic effects of Leucaena leucocephala.

• Grant number: 25/08704-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Sarah Caroline Ribeiro de Souza
• Grantee: Ana Luiza Júdice Costa
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

This study evaluates the potential of Bacillus megaterium and Bacillus subtilis, bacteria that produce siderophores, to mitigate the allelopathic effects of the ethanol extract of seeds of the invasive species Leucaena leucocephala on the germination and initial growth of four legumes: beans, corn, onions, and wheat. Mimosine, an allelochemical present in leucaena, inhibits plant development by impairing physiological processes through competition for nutrients present in the soil. Siderophores, in turn, are secondary metabolites with a high affinity for ferric ions (Fe³¿), capable of making them bioavailable to plants, among other metals, favoring the acquisition of macronutrients. Thus, the experiment will be carried out in vitro with different concentrations of leucaena extract and volumes of bacterial cultures, analyzing parameters such as germination, speed, and ability to collect nutrients under the effect of mimosine. It is expected that, through the chelating action of siderophores, the inhibitory effects of mimosine will be reduced, resulting in greater germination performance and initial growth of the species tested. (AU)