Repression of autocrine pheromone signaling leads to fusaric acid over-production

Abstract

Fusaric acid (FA), a picolinic acid derivative, is a natural substance produced by a wide variety of fungal plant pathogens belonging to the Fusarium genus. As a metabolite, fusaric acid exerts several biological activities including metal chelation, electrolyte leakage, repression of ATP synthesis, and direct toxicity on plants, animals and bacteria. Prior studies on the structure of fusaric acid revealed a co-crystal dimeric adduct between FA and 9,10-dehydrofusaric acid. During an ongoing search for signaling genes differentially regulating FA production in the fungal pathogen Fusarium oxysporum (Fo), we found that mutants lacking pheromone expression have an increased production of FA compared to the wild type strain. Noteworthy, crystallographic analysis of FA extracted from Fo culture supernatants showed that crystals are formed by a dimeric form of two FA molecules (1:1 molar stoichiometry). Overall, our results suggest that pheromone signaling in Fo is required to regulate the synthesis of fusaric acid.

Graphical Abstract

Keywords:

• Pheromone
• Fusarium oxysporum
• fusaric acid
• synchrotron data
• metabolites

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by grants from: the Italian Ministry of Education, University and Research (PRIN-BiPP grant 2020T58TA3) to D.T.; and the Università degli Studi di Napoli Federico II (FRA-Line B-2020-TOPOPATH grant PG/2021/0034842) to D.T. and L.D.C.; and grants by MISE CRESO (Protection no. F/050421/01-03/X32 and Viabio no F/200095/01-03/X45); by Regione Campania (Dioniso no B98H19005010009) and by Regione Veneto (DIVINE no 3589659) to F.V., A.S. and S.V. V. M.G. was supported by the Ph.D. program on ‘Sustainable agricultural and forestry systems and food security’ - XXXVI cycle - Università degli Studi di Napoli Federico II. This study was carried out within the Agritech National Research Center and received funding from the European Union Next-Generation EU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR)—MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4–D.D. 1032 17/06/2022, CN00000022). This manuscript reflects only the authors’ views and opinions, neither the European Union nor the European Commission can be considered responsible for them.