Bacteriófagos recombinantes e miRNAs como estratégias para o controle de Spodoptera frugiperda

Abstract

The caterpillar Spodoptera frugiperda is considered one of the main agricultural pests in Brazil, responsible for severe damage to important crops. Synthetic insecticides and biopesticides have faced limitations such as increased environmental impact and insect resistance to recombinant toxins. Biotechnology is a promising alternative that allow the development of effective strategies to caterpillar combat. The objective of this study was to generate new molecules for the control of S. frugiperda using the biotechnological tool of Phage Display (PhD), when selecting ligand peptides to intestinal proteins, and to predict microRNAs through bioinformatics tools. Using the technology of PhD, we were able to select seven clones whose ability to bind intestinal proteins of S. frugiperda was validated by ELISA and immunohistochemistry. Clone SfF3, when used in combination with Bacillus thuringiensis toxin, promoted an increase in mortality in newborn caterpillars. In addition, it demonstrated similarity to the ATP binding cassette subfamily C2 and cytochrome P450 proteins, which are important for the survival of this pest. As for the miRNAs, 350 precursors of microRNAs present in the genome of S. frugiperda were predicted, being 60 specifics for the genus Spodoptera. In addition, we performed the refinement of RNA-seq libraries available in the NCBI database in search of possible bioinsecticides molecules and 91 of these sequences have not yet been described in the literature, evidencing the perspectives of new sequences as possible alternatives for the regulation of transcripts and consequent alteration in the biology of the caterpillar. Our results validate these technologies as an agrobiotechnological approach to pest control and identify new molecules with bioinsecticide activity, which can be used in combination or in isolation.