Penicillium expansum antifungal proteins: production, evaluation against apple rot and potential synergistic effect

Identifier:  TFG:2177

Handle: https://hdl.handle.net/20.500.11797/TFG2177

Authors:  Monge Escartín, Ana

Abstract:
The shortage of fungicides and the emergence of resistances to them make necessary to look for new antifungal molecules with new action modes. Antifungal proteins (AFP) produced by filamentous fungi are small, highly stable, cationic and cysteine-rich proteins that have an enormous biotechnological interest because of their great antifungal ability. Penicillium expansum is a phytopathogenic fungus that causes blue mold disease in various fruits and vegetables and encodes in its genome three AFPs called PeAfpA, PeAfpB and PeAfpC. PeAfpA is the only one that has been detected to date in the culture supernatants of P. expansum and has shown a relevant activity against different phytopathogens including the fungus itself. In order to go in depth in the characterization of the three AFPs of P. expansum, new tests on their production and antifungal activity have been carried out. In addition to producing PeAfpA, the PeAfpC protein has been detected for the first time in YPD medium regardless of its carbon source, and it is also the first time that simultaneous production of two AFPs of different phylogenetic class by the same strain is described. In contrast, none of the three AFPs were detected during infection of P. expansum in apple. Regarding the antifungal capacity, PeAfpA has not been shown to have a determining protective effect against P. expansum infection in apple trials, highlighting the lack of correlation with in vitro antimicrobial assays. Finally, PeAfpA has been shown to have a synergistic antifungal effect when combined with PeAfpB and PdAfpB from P. digitatum in in vitro assays, suggesting combinations of AFPs as a possible future strategy to increase their activity and enable their application.