Abstract Authors
Tammy G Wallace - Plant Omics Laboratory, Department of Biotechnology, University of the Western Cape
LH Trerise - Plant Omics Laboratory, Department of Biotechnology, University of the Western Cape
AI Daniel - Plant Omics Laboratory, Department of Biotechnology, University of the Western Cape
E Smith - Plant Omics Laboratory, Department of Biotechnology, University of the Western Cape
L Hüsselmann - Plant Omics Laboratory, Department of Biotechnology, University of the Western Cape
Ashwell Klein - Plant Omics Laboratory, Department of Biotechnology, University of the Western Cape
Marshall Keyster - Environmental Biotechnology Laboratory, Department of Biotechnology, University of the Western Cape
Abstract Description
Crown and root rot, caused by Fusarium oxysporum, is a major agricultural challenge that leads to severe yield losses in economically important crops. The widespread use of chemical fungicides to manage this disease raises concerns about environmental sustainability, human health risks, and the emergence of resistant fungal strains. As a result, there is a growing need for eco-friendly and effective alternatives to conventional fungicides. A promising phenolic compound, caffeic acid (CA) has shown to have antioxidant, anti-inflammatory, and antimicrobial potential. This study aimed to evaluate the antifungal potential of CA as a sustainable biocontrol agent against F. oxysporum. Using the food poison technique, we assessed the inhibitory effects of CA on fungal growth, while high resolution scanning electron microscopy was employed to examine morphological changes in fungal cells. Additionally, biochemical responses—including oxidative stress markers, antioxidant enzyme activity (superoxide dismutase and ascorbate peroxidase), and cell wall components (chitin and polysaccharides)—were analysed using spectrophotometric assays. The impact of CA on fungal pathogenicity was further investigated by measuring cellulase and lipase enzyme activity, and proteomic profiling was conducted to identify differentially expressed proteins associated with stress response, metabolism, and virulence. Our findings demonstrate that CA effectively inhibits the growth of F. oxysporum, particularly at a higher concentration (1 mM). CA disrupts fungal cell membranes, induces oxidative stress, and increases cell death. Furthermore, it significantly reduces the activity of key fungal enzymes linked to pathogenicity, such as lipases and cellulases. Proteomic analysis displayed significantly altered proteins highlighting affected resistance mechanisms within fungal cells. These results suggest that CA possesses strong antifungal properties and holds promise as a natural alternative to synthetic fungicides. Its application in priming wheat seeds could enhance plant resistance to Fusarium crown rot infections. Further studies on its implementation in crop protection strategies could provide practical benefits for sustainable agriculture.
