Approaches based on insect behavior and plant electrophysiology to evidence aphid- and imidacloprid-mediated stress in non-Bt and Bt cotton

• Autor(a) principal: Pachú, Jéssica Karina da Silva
• Data de Publicação: 2021
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/11/11146/tde-13092021-141556/
• topic: Algodoeiro; Bioelectricity; Bioeletricidade; Cotton; Cotton aphid; Fisiologia; Physiology; Pulgão do algodão

Plants are capable of emitting, processing, and transmitting electrical signals under unfavorable conditions. Therefore, this study aimed to characterize the production of electrical signals in Bt and non-Bt cotton plants (Gossypium hirsutum L.) infested with Aphis gossypii and characterize the dispersal behavior of these aphids to relate this behavior to the responses of plant signaling. Additionally, we evidenced the photosynthetic and electrical responses of the plant to the stress caused by the herbivory of A. gossypii combined with the stress generated by the use of imidacloprid, and we also evaluated how this stress can influence the behavioral ecology of the predator Cycloneda sanguinea and its prey. The results showed that both the Bt and non-Bt cotton varieties, when attacked by A. gossypii, emitted electrical signals of the variation potential type and clearly showed the presence of distinct responses regarding their perception and behavior of aphids. In addition to recording the generation of plant variation potentials, there were changes in the cotton respiration rate mediated by the application of the insecticide. Imidacloprid also caused high locomotion in C. sanguinea males. The results obtained here motivate future studies that aim to elucidate the factors involved in the processes of resistance to stress and plant defense and, thus, can be used as a tool for the implementation of integrated management programs in the search for conservation and greater efficiency and sustainability of the agroecosystem and to highlight the possible impacts of the use of imidacloprid on the electrophysiology of plants even in cases of nonoccurrence of the aphid A. gossypii.