Search for micro RNAs (miRNA) potentially involved in resistance to infestation by Mahanarva spectabilis leafhoppers in the native forage Paspalum regnellii

• Grant number: 24/01921-7
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2024
• End date: June 30, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Anete Pereira de Souza
• Grantee: Anete Pereira de Souza
• Host Institution: Centro de Biologia Molecular e Engenharia Genética (CBMEG). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 22/04006-2 - Center for Plant Molecular Breeding (CeM²P), AP.PCPE
• Associated scholarship(s): 24/12386-5 - Search for micro RNAs (miRNA) potentially involved in resistance to infestation by Mahanarva spectabilis leafhoppers in the native forage Paspalum regnellii, BP.JD

Abstract

Agribusiness is responsible for 27% of Brazil's gross domestic product, being the most prominent sector in the country's economy. Pastures are the dominant component in this sector, occupying a third of the national territory. However, its productivity has been seriously affected by pests such as spittlebug, including those of the species Mahanarva spectabilis, which generate losses of around 2 billion dollars annually to meat and milk production. Tropical forages are the main food for national livestock, with the vast majority of forage species used being susceptible to attack by spittlebug. As an exception, the species Paspalum regnellii, which presents natural resistance to these attacks and good forage potential, stands out as a model for the study of this resistance in forage plants. The spittlebug M. spectabilis is a species that is difficult to control due to the fact that its nymphs remain buried and secrete a thick foam, and these characteristics protect them from predators and chemical substances. In the current scenario, both herbicides and alternative biological control methods have proven to be inefficient in controlling spittlebug. In this scenario, the development of new methods of controlling spittlebug is essential. Recently, micro RNA (miRNA) has attracted attention as a source of resistance to pests in plants. The expression of these molecules can silence specific genes of the host plant and pest, impacting the metabolism of both and triggering defense and resistance processes. Resistance-promoting miRNAs are relatively known in model cultivars such as wheat and soybeans, but there is no information on tropical forages. The identification of these molecules in P. regnellii is extremely important for national livestock farming, as they can be used as a source of resistance to spittlebug attacks in phylogenetically close forage species, whether through exogenous application, crossing or transgenics. Given the facts, we propose to study the expression profile of Paspalum regnellii miRNA under spittlebug infestation. To achieve this, the experiment will consist of inoculating M. spectabilis eggs into the roots of P. regnellii plants. After the development and fixation of the nymphs on the roots, samples of root and leaf tissue will be collected in two situations, the control (C) being uninfected plants and T1 plants being infected for 72 hours. After extraction and sequencing of miRNA from these samples, we will investigate which miRNA sequences will be under differential expression and their possible roles in the acquisition of resistance to spittlebug. In the end, a list will be generated with the miRNAs indicated as promoters of resistance to spittlebug. Such information can be used in the development of new methods to control spittlebug in pastures, which are more effective and ecologically appropriate. (AU)