Banca de DEFESA: MANOELY ABREU REIS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MANOELY ABREU REIS
DATE: 31/07/2024
TIME: 08:00
LOCAL: REMOTO - Videoconferência
TITLE:

UNRAVELING THE REGULATION OF THE IMMUNE SYSTEM OF Diatraea saccharalis IN RESPONSE TO DIFFERENT BIOLOGICAL CONTROL AGENTS

KEY WORDS:

Sugarcane Borer, gene regulation, insect-pathogen interaction

PAGES: 170
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:

Insects do not possess an adaptive immune system like vertebrates. They primarily rely on the innate immune system, composed of humoral and cellular responses, to defend against parasites and pathogens. The humoral response consists of various signaling pathways that result in the production of molecules such as antimicrobial peptides (AMPs) and melanin, which act against the invading agent. Despite numerous studies describing the types of responses and signaling pathways of the insect immune system to different pathogens, most are conducted with model insects or with non-natural pathogens. This study investigated different aspects of the immune system of Diatraea saccharalis (Lepidoptera: Crambidae), the major pest of sugarcane in Brazil. In the first study, the main genes involved in the signaling pathways of the humoral response were characterized: Toll, IMD, Jak-STAT, and the Profenoloxidase (melanization) pathway. After characterization, the modulation of at least one representative gene from each pathway was investigated in insects treated with different biological control agents, such as the bacterium Bacillus thuringiensis (Bt), the fungus Metarhizium anisopliae, and the parasitoid Tetrastichus howardi. In the second study, the focus was on the characterization of AMPs in D. saccharalis, highlighting a lebocin, a proline-rich peptide, which shows increased expression in the heads of larvae fed on sugarcane or when ingesting Bt spores and crystals. In the final study, it was examined whether T. howardi would induce immunological priming in D. saccharalis adults, with positive effects on the pest's offspring. Immunological priming occurs when a past exposure or infection leads to a more effective immune response upon a secondary exposure. However, the offspring of D. saccharalis were more susceptible to the parasitoid due to compromised immunity caused by prior exposure. From these results, new aspects of the immune system of D. saccharalis were unveiled, which can contribute to the improvement of the use of biological control agents as well as the development of new sustainable pest control technologies.

COMMITTEE MEMBERS:
Presidente - JOSE DIJAIR ANTONINO DE SOUZA JUNIOR
Externo à Instituição - ERICH YUKIO TEMPEL NAKASU - EMBRAPA
Externa à Instituição - CLIDIA EDUARDA MOREIRA PINTO - EMBRAPA
Externo à Instituição - GUILHERME DUARTE ROSSI - UNESP
Externo à Instituição - RICARDO ANTONIO POLANCZYK - UNESP