Antioxidants and iron chelators inhibit oxygen radical generation in fungal cultures of plant pathogenic fungi. Issue 8 (August 2022)

• Record Type: Journal Article
• Authors: Sebestyen, Dana; Perez-Gonzalez, Gabriel; Goodell, Barry
• Is Part Of: Fungal biology. Volume 126:Issue 8(2022)
• Page Start: 480
• Page End: 487
• Publication Date: 2022-08
• Subjects: Grapevine trunk disease (GTD) -- Wood decay pathogens -- Hydroxyl radicals -- Eutypa lata -- Phaeoacremonium minimum -- Phaeomoniella chlamydospora; Mycology -- Periodicals; Fungi -- Periodicals; 579.505
• DOI: 10.1016/j.funbio.2022.04.002
• Languages: English
• ISSNs: 1878-6146

Abstract

Abstract: Eutypa dieback and Esca are serious fungal grapevine trunk diseases (GTDs). Eutypa dieback is caused by Eutypa lata (Elata), and is often associated Phaeoacremonium minimum (Pmin), and Phaeomoniella chlamydospora (Pch) which are also important contributors to Esca disease. Understanding the complex pathogenesis mechanisms used by these causative fungi may potentially lead targeted treatments for GTDs in the future. Elata has been reported as a wood decay "soft rot" fungus and understanding of Elata's pathogenesis chemistries can aid in controlling GTDs. Recent work that suggests that Pmin and Pch may contribute to pathogenesis by stimulating hydroxyl radical generation via secretion of low molecular weight phenolic metabolites. Building on these findings, we tested a hypothesis that antioxidants and chelators, and biocontrol agents that have been reported to secrete antioxidants and low molecular weight chelators, may inhibit the growth and activity of these fungi. Butylated hydroxy anisole (BHA) and butylated hydroxytoluene (BHT) were tested as antioxidant/chelators. BHA was found to be a highly effective control measure for the three pathogenic fungi tested at concentrations >0.5 mM. The biocontrol species Bacillus subtilis and Hypocrea (Trichoderma) atroviride were also tested, with both H. atroviride and B. subtilis effectively inhibiting growth of the three GTD fungi. Highlights: Salicylic acid and EDTA prevent iron reduction and hydroxyl radical ( OH) production by metabolites produced by GTD fungi. BHA, BHT, salicylic acid, and EDTA block mediated Fenton chemistry, reducing OH generation by fungal metabolites. BHA, EDTA, and Bacillus subtilis were effective in inhibiting fungal growth involved in Esca and Eutypa dieback disease.