THIONIN-LIKE ANTIMICROBIAL PEPTIDE: INHIBITORY ACTIVITY AND SYNERGISM EFFECT AGAINST Fusarium solani.

TAVEIRA, G; CARVALHO, A.; RODRIGUES, R; REGENTE, MC; PINEDO, M.; DE LA CANAL L; GOMES, V.

Mar del Plata

Congreso; LI Congreso de la Sociedad Argentina de Investigación Bioquímica; 2015

Sociedad Argentina de Investigación Bioquímica

We have previously isolated a thionin-like antimicrobial peptide, CaThi, from Capsicum annuum fruits. The aim ofthis work was the investigation of the mechanism of action from CaThi and additionally its combinatory effect withfluconazole against Fusarium solani. As method, CaThi was assayed for antimicrobial activity, plasma membranepermeabilization ability, induction of intracellular reactive oxygen species and localization of CaThi tagged withFITC in F. solani cells. To determine the possible synergistic effect, F. solani was grown in the presence of CaThi incombination with fluconazole. After this assay, viability was determined. Our results showed that CaThi inhibits 82%of growth, prevents the formation of F. solani hyphae from spores, changes their membranes, induces production ofhydrogen peroxide, and it is localized intracellularly. The assay with CaThi in combination with fluconazole reaches100% inhibition and causes 100% viability loss. In conclusion we show that CaThi has strong activity against F.solani, inhibits the spore germination and induces its permeabilization and hydrogen peroxide accumulation. Theresults suggest the occurrence of an intracellular target for CaThi. Combination of fluconazole and CaThi increasedthe inhibitory activity, suggesting that a synergistic mechanism causes spores 100% viability loss.