Antifungal activity of soapberry pericarp extracts: an effective approach against plant pathogenic fungi

Sapindus mukorossi, a versatile woody plant utilized in biomass energy, biotechnology and landscaping, has been the focus of this study. The primary objective was to assess the antifungal potential of soapberry pericarp extracts against several common plant pathogenic fungi.

The investigation revealed that the soapberry pericarp extract displayed broad-spectrum antifungal activity against six plant pathogenic fungi. Notably, it effectively inhibited the spore germination of Verticillium dahliae and Fusarium oxysporum. In subsequent inoculation trials with V. dahliae, the soapberry extract significantly reduced the incidence of cotton verticillium wilt compared to the control. Additionally, cotton treated with the extract showed a higher upregulation of disease-resistance genes PR1 and PR5 postinfection with V. dahliae. The extract also suggested a potential growth-promoting effect. In fruit biocontrol assays, it demonstrated remarkable antifungal activity against Botryitis cinerea in tomato, preventing mycelial expansion at the inoculation site, and reduced Penicillium digitatum infection in citrus to merely 13%, in contrast to 85% in the control. Extraction experiments further confirmed that using water as the solvent was the most efficient and economical method for extracting antifungal active components from soapberry pericarp.

The study concluded that soapberry pericarp extracts possess significant broad-spectrum antifungal properties, showing promise as a potential alternative for plant disease management and fruit biocontrol. The water extraction method identified offers an effective and cost-effective way to harness these beneficial antifungal components. © 2025 Society of Chemical Industry.