Synthesis and secretion of volatile short-chain fatty acids in Triatoma infestans infected with Beauveria bassiana

LUZ, C.; GIROTTI, J. R.; LUZ, C.; GIROTTI, J. R.; PEDRINI, N.; MIJAILOVSKY, S. J.; FERNANDES, É. K. K.; PEDRINI, N.; LOBO, L. S.; MIJAILOVSKY, S. J.; FERNANDES, É. K. K.; LOBO, L. S.

MEDICAL AND VETERINARY ENTOMOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2018 vol. 32 p. 358 - 364

0269-283X

Physically disturbed Triatoma infestans (Hemiptera: Reduviidae) adults, as well as those of other Chagas disease vectors, secrete a mix of volatile organic compounds (VOCs) with alarm and possible sexual and defense function. The aim of the present research was to test whether the infection with the entomopathogenic fungus Beauveria bassiana (Ascomycota: Hypocreales) has an effect on VOCs secretion by disturbed T. infestans and on the expression of two genes (Ti-brnq and Ti-bckdc) potentially involved in their biosynthesis. The volatiles released by insects at different time periods after fungal treatment were identified and their relative amounts measured. Isobutyric acid was the most abundant volatile found in both healthy and fungus-infected insects, and underwent no significant relative changes through the infection progress. The secretion of propionic acid, however, was significantly higher at 1?4 days post infection (dpi) compared with controls. A slight induction of both Ti-brnq and Ti-bckdc genes was found by real-time PCR at 4 dpi, with values reaching up to 3-fold expression over the controls. Early stages of fungal infection seem to affect the composition of alarm pheromone by changing the expression pattern of both genes analyzed. These results help to better understand the impact of fungal infections on chemical ecology of triatomine bugs.