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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #379044

Research Project: Integrated Management of Fungal Pathogens in Peanut to Reduce Mycotoxin Contamination and Yield Losses

Location: National Peanut Research Laboratory

Title: Non-destructive SPE-UPLC-based quantification of aflatoxins and stilbenoid phytoalexins in single peanut (arachis spp.) seeds

item Sobolev, Victor
item Arias De Ares, Renee
item Massa, Alicia
item Walk, Travis
item Orner, Valerie
item Lamb, Marshall

Submitted to: Journal of Visualized Experiments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2024
Publication Date: 4/19/2024
Citation: Sobolev, V., Arias De Ares, R.S., Massa, A.N., Walk, T., Orner, V.A., Lamb, M.C. 2024. Non-destructive SPE-UPLC-based quantification of aflatoxins and stilbenoid phytoalexins in single peanut (arachis spp.) seeds. Journal of Visualized Experiments. (206). Article e65574.

Interpretive Summary: We demonstrate a medium-throughput method for quantification of aflatoxins and stilbenoid phytoalexins in single peanut seeds using UPLC. This method was specifically developed for the analyses of wild Arachis species challenged by the aflatoxigenic Aspergillus species.

Technical Abstract: Aflatoxins are highly carcinogenic secondary metabolites of some fungal species, particularly Aspergillus flavus. Aflatoxins often contaminate economically important agricultural commodities, including peanuts, posing high risk to human and animal health. Due to the narrow genetic base, peanut cultivars demonstrate limited resistance to fungal pathogens. Therefore, numerous wild peanut species with resistance to Aspergillus, have received substantial consideration by scientists as sources of disease resistance. Exploring plant germplasm for resistance to aflatoxins is difficult since aflatoxin accumulation does not follow a normal distribution, which dictates the need for the analyses of thousands of single peanut seeds. Sufficiently hydrated peanut (Arachis spp.) seeds, when infected by Aspergillus species, are capable of producing biologically active stilbenes that are considered defensive phytoalexins. Peanut stilbenes inhibit fungal development and aflatoxin production. Therefore, it is crucial to analyze the same seeds for peanut stilbenoids in order to explain the nature of seed resistance/susceptibility to the Aspergillus invasion. None of the published methods offer single seed analyses for aflatoxins and/or stilbene phytoalexins. We attempted to thedemand for such a method that is environment-friendly, used inexpensive consumables, sensitive, and selective. In addition, the method is non-destructive since it uses only half of the seed and leaves the other half containing the embryonic axis intact. Such a technique allows germination and growth of the peanut plant to full maturity from the same seed used for the aflatoxin and stilbenoid analysis. The integrated part of this method, manual challenging of the seeds with Aspergillus, is a limiting step that requires more time and labor compared to other steps in the method. The method has been used for the exploration of wild Arachis germplasm to identify species resistant to Aspergillus and to determine and characterize novel sources of genetic resistance to this fungal pathogen.