Elucidating the molecular mechanisms associated with the resistance of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) to spinetoram

• Grant number: 25/03257-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2025
• End date: February 28, 2027
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Celso Omoto
• Grantee: Carolina Pacchioni Monteiro
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The evolution of resistance to insecticides in Spodoptera frugiperda (J. E. Smith) represents one of the main challenges for the effective implementation of Integrated Pest Management (IPM) programs. Recently, the resistance of S. frugiperda to spinetoram, an insecticide of the spinosyn chemical group, which act as allosteric modulators of nicotinic acetylcholine receptors (nAChR), was detected and characterized in Brazil. The main molecular mechanisms already reported for the resistance of S. frugiperda to spinetoram include the Y232del mutation, located in the nAChR alpha6 gene, and a suppression of detoxification enzymes. This last factor, in particular, opens a gap for the investigation of possible gene regulation by non-coding RNAs (ncRNAs), including microRNAs (miRNAs). Therefore, to better elucidate the molecular mechanisms associated with the resistance of S. frugiperda to spinetoram, this project aims to (i) verify the presence of the Y232del mutation in field populations of S. frugiperda collected in the main maize-producing regions in Brazil as a strategy for genotypic monitoring of the evolution of resistance compared to phenotypic monitoring, in addition to (ii) identify and analyze the expression profile of differentially expressed miRNAs using qRT-PCR. The results obtained seek to contribute to the improvement of innovative strategies for Insecticide Resistance Management (IRM), aiming to ensure the sustainability of IPM programs for S. frugiperda in Brazil.