Systemic approach in insect - plant - microorganism interactions: using insect-associated microorganisms as endophytes to improve plant growth and plant defense to pests

• Ano de defesa: 2025
• Autor(a) principal: Achre, Diandra
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Bactérias promotoras do crescimento de plantas; Controle de pragas; Insect-associated microorganisms; Insect-plant interaction; Interação inseto-planta; Microrganismo associado a insetos; Pest control; Plant growth-promoting bacteria
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11146/tde-13052025-144224/

The rising demand for food driven by the global population growth requires the expansion of agricultural productivity through sustainable solutions that minimize the use of chemical pesticides and reduce environmental impacts. In this context, insect-associated microorganisms have emerged as promising alternatives due to their ability to modulate plant metabolism and physiology, promoting plant growth and inducing and/or modifying plant defense responses. Previous results have demonstrated the biopesticidal efficacy and the growth-promotion potential of a group of insect-associated bacteria as inoculants of maize plants. Despite the identification of the efficacy of these bacteria, the pest-plant- microorganism system under study still requires additional studies to improve our knowledge on the changes these bacteria produce in the plants and herbivore to allow their applied use as maize endophytes, either to promote plant growth or to control herbivore activity, via modulation of the plant defense response, and/or control diseases, via activation of the plant immune response. In this work, we investigated how insect-associated microorganisms can modulate different aspects of the biology and physiology of maize plants and affect maize interactions interactions with herbivores and pathogens. We analyzed the metabolome, transcriptome and proteome of control maize plants and plants inoculated with insect-associated bacteria, and of the larvae of the herbivore Spodoptera frugiperda after feeding on such maize plants. Furthermore, we explored the potential of the tested bacteria in inducing the immune response in maize against the phytopathogen Spiroplasma kunkelii, using Dalbulus maidis as an experimental vector. A systemic understanding of the mechanisms involved in plant-insect-symbiont-pathogen interactions opens prospects for developing innovative technologies for improved pest management and increased agricultural productivity. These strategies represent a promising and sustainable approach to increase resilience of agricultural systems.