Sodium pheophorbide a has photoactivated fungicidal activity against Pestalotiopsis neglecta

• Published in: Pesticide biochemistry and physiology Vol. 158; pp. 25 - 31
• Main Authors: Jing, Yang, Lian-Nan, Lin, Xiao-Bo, Zhang, Yue, Wu, Bing, Bi, Guo-Cai, Zhang, Chuan-Shan, Zou
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2019
• Subjects: Antifungal Agents - pharmacology; Antifungal mechanism; Chlorophyll - analogs & derivatives; Chlorophyll - pharmacology; Enzyme activity; Lipid Peroxidation - drug effects; Microbial Sensitivity Tests; Microscopy, Electron, Scanning; Mycelium - drug effects; Mycelium - ultrastructure; Pestalotiopsis neglecta; Photoactivated fungicide; Radiation-Sensitizing Agents - pharmacology; Scanning electron microscope; Sodium pheophorbide a; Antifungal mechanism; Sodium pheophorbide a; Enzyme activity; Pestalotiopsis neglecta; Photoactivated fungicide; Scanning electron microscope
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1016/j.pestbp.2019.04.003

Sodium pheophorbide a (SPA) is a natural photosensitizer. To explore its antifungal activity and mechanism, we studied its inhibitory effects on spore germination and mycelial growth of Pestalotiopsis neglecta. We used sorbitol, 2-thiobarbituric acid (TBA) and electron microscopy to determine its effects on cell wall integrity, cell membrane lipid peroxidation and mycelial morphology. Finally, the effects of SPA on enzyme activity in mycelia were determined. The results showed that SPA effectively inhibited spore germination and mycelial growth of P. neglecta under light conditions (4000 lx, 24 h). Scanning electron microscopy (SEM) revealed that SPA treatment resulted in a roughened, twisted and knotted mycelial surface and abnormal mycelial growth. SPA influenced cell wall integrity, and the content of MDA, a cell membrane lipid peroxidation product was significantly increased (P < 0.05). SPA also significantly inhibited SOD, POD and PG activity, but enhanced PPO activity (P < 0.05). In conclusion, SPA may have potential to become a biological pesticide. [Display omitted] •Sodium pheophorbide a (SPA) has a good photoactivated fungicidal activity.•Cell wall and cell membrane are important target sites of SPA against P. neglecta.•SPA inhibits SOD, POD and PG activity, but enhances PPO activity of P. neglecta.