Antifungal activity of potato glycoalkaloids and its potential to control severity of dry rot caused by Fusarium sulphureum

Abstract

Identifying novel sources of antifungal agents from common food waste (i.e., green potato peel) could provide an inexpensive alternative for botanical fungicides. Identification of the potato (Solanum tuberosum L.) glycoalkaloids (PGAs) content in the green peel by high performance liquid chromatography (HPLC), and the antifungal activity of PGAs against the potato dry rot pathogen Fusarium sulphureum were evaluated using addition of PGAs to the medium in vitro and injection of it into potato tubers in vivo. The results of HPLC showed that the average content of PGAs per kilogram green potato peel was 2238.76 mg, and the α-chaconine content was about 1.8 times higher than that of α-solanine. Antifungal activity test of PGAs in vitro uncovered that mycelium growth rate of F. sulphureum was inhibited in potato dextrose agar (PDA) medium with varying concentrations of PGAs, and the inhibition rate was positively correlated with PGAs concentration. Moreover, PGAs were also capable of reducing the contents of malondialdehyde, total phenols, flavonoids as well as the activities of peroxidase and superoxide dismutase induced by F. sulphureum through inhibiting or killing part of mycelium. These findings suggest that the protective effect of PGAs against potato dry rot might be associated with the direct fungistatic effect on the pathogen. Thus, PGAs can serve as a promising botanical fungicide to substitute, at least partially, the use of synthetic fungicides in the disease management of potato.

Potato glycoside alkaloids exhibit antifungal activity by regulating the tricarboxylic acid cycle pathway of Fusarium solani

“…PGA could inhibit the colony growth of pathogenic fungi such as A. solani ( Wolters et al, 2023 ) and P. brasiliense ( Joshi et al, 2021 ). PGA inhibited the mycelial growth rate and spore germination of C. trifolii ( Xu et al, 2023 ), and inhibited the growth of F. sulphureum by inhibiting ROS metabolism and destroying cell membrane ( Li et al, 2023 ).…”

“…It has been reported that PGA can inhibit the growth and development of Botrytis cinerea ( Sun et al, 2014 ), Pectobacterium carotovorum ( Rocha et al, 2015 ), Alternaria alternata and Pyrenophora tritici-repentis ( Sanchez-Maldonado et al, 2016 ), Phytophthora infestans ( Dahlin et al, 2017 ). PGA could inhibit the spore germination of Curvularia trifolii ( Xu et al, 2023 ), reduce the virulence of Pectobacterium brasiliense ( Joshi et al, 2021 ), inhibit the active oxygen metabolism process of F. sulphureum to exert antifungal effect ( Li et al, 2023 ).…”

Modulation of the glycoalkaloid biosynthesis pathway in potato (Solanum tuberosum L.) and development of CRISPR/Cas9 methodology for tomato (Solanum lycopersicum L.)

“…The foliar total glycoalkaloids (TGA) level in potatoes is highly associated with resistance against pests, such as the Colorado potato beetle (Leptinotarsa decemlineata) and the potato leafhopper (Empoasca fabae) (Sinden et al 1980;Tingey 1984;Sanford et al 1992;Friedman et al 1997). It has also been shown that α-chaconine can inhibit the growth of several fungi and nematodes (Fewell & Roddick 1993;Li et al 2022).…”

Plant microbiomes as contributors to agricultural terroir

“…spermidine) and osmoregulatory hexoses (Castro-Moretti et al, 2020). Elevated levels of glycoalkaloids (toxic to humans) are produced in potato tubers trying to resist root rot pathogens like Fusarium sulphureum (Li et al, 2022). In a wonderful example of a soil microbiome preserving a healthy plant metabolome, maize was grown on sterile sand inoculated with soil bacteria that had been filter purified of all protists (predators of bacteria), while some plants were also inoculated with a blend of these bacterial predators: the ciliate (Tetrahymena pyriformis), an amoebae (Acanthamoeba polyphaga) and a flagellate (Cercomonas longicauda).…”