Work

The Antifungal Activity and Mechanism of Dehydroabietic Acid Against Alternaria alternata Causing Poplar Leaf Spot

Year: 2025

Type: article

Abstract: Dehydroabietic acid (DHA) is a secondary metabolite isolated from rosin, which has certain antifungal activity, but its inhibitory effects against Alternaria alternata are unclear. In the present study, we found that DHA inhibited the mycelial growth of A. alternata, Botrytis cinerea, Valsa mali, Pestalotiopsis neglecta, and Fusarium oxysporum in a concentration-dependent manner, with the best inhibitory effect against A. alternata. Moreover, DHA can also inhibit the spore germination of A. alternata. Then, in vivo inoculation experiments showed that the leaf lesions of Populus alba gradually decreased with the increase in DHA concentration. The disease of P. alba leaves inoculated with A. alternata was not obvious after treatment with 800 mg/L DHA. The scanning electron microscopy showed that the mycelial morphology was abnormal, with crinkles and depressions. Meanwhile, the relative conductivity, soluble protein content, malondialdehyde content and hydrogen peroxide content of A. alternata were significantly increased after DHA treatment, which affected the integrity of the cell membrane and increased the permeability of A. alternata, resulting in a large leakage of intracellular substances, exacerbating the degree of lipid peroxidation of the cell membrane of A. alternata and causing oxidative damage to cells. The enzyme activity assay showed that treatment with 56.015 mg/L (EC50) DHA significantly reduced the activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase) and cell-wall-degrading enzymes (endoglucanase, polygalacturonase, pectin lyase) in A. alternata (p < 0.05), resulting in a decrease in the activity of pathogenic fungi, as well as a reduction in the ability of the A. alternata to degrade the cell wall of the host plant, which led to a decrease in the ability of the A. alternata to infest the host plant. Moreover, the decrease in the relative expression of defense-related enzyme genes (AaSOD, AaPOD, AaCAT) and pathogenicity-related enzyme genes (AaPL, AaPG) was consistent with the enzyme activity results. Thus, the present study revealed the fungicidal activity and mechanism of DHA against A. alternata and the potential of DHA to be developed as a plant-derived antifungal agent was established.

Source: Journal of Fungi

DOI: 10.3390/jof11040265

Authors: Yun-Ze Chen, Yun-Di Zhang, Cheng Chen, Qiu-Er Sa, Jing Yang, Guo-Cai Zhang

Institutions: Guizhou Education University, Northeast Forestry University, Guizhou University

Language: English

Topic: Fungal Plant Pathogen Control

Subfield: Ecology, Evolution, Behavior and Systematics

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $3,137