Synthesis and secretion of volatile organic compounds by Triatoma infestans infected with Beauveria bassiana

L.S. LOBO; S.J. MIJAILOVSKY; C. LUZ; E.K.K. FERNANDES; M. P. JUAREZ; N. PEDRINI

Mainz

Congreso; 47th Annual Meeting of the Society for Invertebrate Pathology. 2014 International Congress on Invertebrate Pathology and Microbial Control; 2014

Society for Invertebrate Pathology

Physically disturbed Triatoma infestans adults secrete volatile organic compounds (VOC) with alarm and defense function. It is still unclear whether infection with entomopathogenic fungi changes or not the profile of these volatiles. The aim of the present research was to characterize VOC released by T. infestans adults infected with B. bassiana and to study the expression of genes (Ti- brnq and Ti-bckdc) potentially involved in the biosynthesis of these volatiles in triatomines infected or not. Volatiles released by T. infestans on different periods after treatment (1-4, 6-10, 11-15 days) were quantified and identified employing capillary gas chromatography coupled to mass spectrometry.The expression pattern of Ti- brnq and Ti-bckdc was analysed by real-time PCR, 4 and 10 days after treatment. Isobutyric acid was the most abundant VOC found (70 to 78% of the total) with no significant effect of the progress of infection on quantitative production of this compound. Secretion of propionic acid, however, was highest in the beginning (18.6 ± 5.8%) and decreased distinctly with the progress of infection and at this time did not differ from values found for the control. Highest expression of both genes was found on insects 4 days after treatment. Significant difference was found inTi- brnq expression, with 1.3 ± 0.5 fold induction; Ti-bckdc expression resulted in 1.9 ± 0.3 fold induction. No induction was observed at 10 days after treatment. The results help to understand better the impact of fungal infection on the chemical ecology of T. infestans.