Fungicidal effects of garlic-based bioactives in crop protection

Kounadi, Stella (2022) Fungicidal effects of garlic-based bioactives in crop protection. Doctoral thesis, University of East Anglia.

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Abstract

Garlic (Allium sativum) has long been renowned for its antimicrobial activity and medicinal properties. This biological activity arises from the wide range of garlic’s organosulfur compounds, such as diallyl polysulfides (DAS), which are highly reactive molecules with complex modes of action. DAS contain one to six sulfur atoms in a linear chain with two allyl groups at each end of the molecule. This study demonstrated the antifungal effect of DAS on the fungus Neurospora crassa. DAS exert higher bioactivity with increasing sulfur chain length, a property that was demonstrated in this study. Additionally, the role of ergothioneine, a low molecular weight thiol exclusive to fungi, in protection against DAS-induced stress was also investigated.

Currently, there is an increasing interest in the use of garlic chemistry for crop protection, as an alternative to synthetic fungicides with lower environmental risk. Because of the multiple modes of action of DAS inside cells the chance of antifungal resistance development becomes very small. In this study, the approach of experimental evolution was used to explore whether garlic oil can lead to resistance development.

Heavy metals, such as copper and zinc, are used for crop protection, however, extensive use leads to accumulation in soil with toxic consequences for plants, microorganisms, and human health. It was explored whether combinations of these metals with garlic oil show increased potency and could be used as an alternative way to reduce the use of copper in agriculture. In addition, the development of a garlic-based fungicidal strategy for crop protection was investigated with a pea field trial and a series of pot experiments. In some cases, garlic-derived formulations showed promising results in inhibiting the fungal diseases of peas and showed a growth promoting effect on plant development.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Pharmacy
Depositing User:	Chris White
Date Deposited:	03 Jul 2024 11:24
Last Modified:	03 Jul 2024 11:24
URI:	https://ueaeprints.uea.ac.uk/id/eprint/95776
DOI:

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