Guaiacol as a natural melanin biosynthesis inhibitor to control northern corn leaf blight. Issue 11 (29th July 2022)

• Record Type: Journal Article
• Authors: Wang, Delong; Li, Min; Yuan, Chunxia; Fang, Yali; Zhang, Zhijia
• Is Part Of: Pest management science. Volume 78:Issue 11(2022)
• Page Start: 4557
• Page End: 4568
• Publication Date: 2022-07-29
• Subjects: northern corn leaf blight -- plant essential oil compounds -- DHN melanin biosynthesis inhibitor -- guaiacol; Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.7075
• Languages: English
• ISSNs: 1526-498X

Abstract

Abstract: BACKGROUND: The natural 1, 8‐dihydroxynaphthalene (DHN) melanin biosynthesis inhibitors (MBIs) are one of the promising approaches to the integrated management of plant diseases but have received scarce attention until now. Herein, to explore the natural DHN MBIs used in the control of northern corn leaf blight (NCLB), a library of 53 essential oil compounds was used to screen the MBIs against Exserohilum turcicum, the causal pathogen of NCLB, using tricyclazole as a reference compound. RESULTS: The results of morphological change in the colony, thermogravimetric analysis, ultraviolet–visible spectroscopy, and transmission electron microscopy confirmed that guaiacol could effectively inhibit the melanin production at 50 μg/mL under in vitro conditions. The in vitro bioassay results indicated that this inhibition effect was concentration‐dependent and the minimum inhibition concentration of guaiacol was 50 μg/mL. The in vivo experimental results demonstrated that guaiacol significantly inhibited appressorium formation and penetration on corn leaf sheaths at the concentration of 500 μg/mL. The pot experiment results revealed that there were no differences between guaiacol (500 μg/mL) and tricyclazole (100 μg/mL) in control efficacy. The enzymatic assay suggested that guaiacol might exert the activity through inhibiting DHN polymerization to form melanins, which was distinct from tricyclazole. CONCLUSIONS: Taken together, this study screened out guaiacol as a natural MBI from 53 essential oil compounds and verified its effectiveness in the control of NCLB at 500 μg/mL. Above all, this research opened an avenue for exploring natural DHN MBIs in the integrated management of plant diseases. © 2022 Society of Chemical Industry. Abstract : Guaiacol was screened out as a DHN melanin biosynthesis inhibitor. It inhibits melanin biosynthesis when the concentration above 50 μg/mL and efficiently controls northern corn leaf blight at 500 μg/mL.