Insect associated bacterial symbionts as bioremediators, suppressorrs of insect pests, plant growth stimulants and reducers of methane emissions by pesticide-contaminated soils

• Grant number: 25/04139-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: April 30, 2029
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Fernando Luis Cônsoli
• Grantee: Iara Uliana Moraes Sampaio
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 21/10573-4 - Center for Carbon Research in Tropical Agriculture (CCARBON), AP.CEPID

Abstract

Pesticides and by-products of their degradation interfere with the diversity and functional contribution of soil microbiome, affecting carbon sequestration mediated by soil microbiota. Changes in soil microbiota also influence soil fertility and impair the soil suppressive capacity. Moreover, disturbance of the soil microbial community can alter the relative abundancy of methanogens to methanotrophs, increasing the emission of methane, the second most noxious contributor to global warming. The sole reduction of the overall microbial density in soils has been shown to elevate the emission of methane from pesticide-contaminated soils. Strategies designed to accelerate pesticide degradation and reduce methane emissions while maintaining soil microbiota diversity and the bacterial functional contribution are relevant to pave the ways to generate technologies to guarantee the practice of a carbon-based sustainable agriculture. Insect-associated microbes can contribute to host plant adaptation, increased resistance to biotic and abiotic factors, including pesticides. We have isolated a high number of gut bacteria from lab-selected insecticide resistant strains of Spodoptera frugiperda and from field-collected larvae that can metabolize a high diversity of pesticides. Most of the pesticide-degrading bacteria isolated from S. frugiperda belong to Firmicutes and Proteobacteria. Some of these bacteria were also demonstrated to induce plant growth and plant resistance to herbivore attack. In this project we want to select a diverse group of pesticide-degrading bacteria to enrich the microbiota of pesticide-contaminated soils to investigate their potential to speed the degradation of pesticides, induce plant growth and resistance to insect pests and reduce methane emissions.