Metabolite profiling of a fast neutron soybean mutant reveals an increased abundance of isoflavones

Authors: Islam, Nazrul - Naz; Krishnan, Hari; Slovin, Janet; Natarajan, Savithiry - Savi

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/22/2023
Publication Date: 6/21/2023
Citation: Islam, N., Krishnan, H.B., Slovin, J.P., Natarajan, S.S. 2023. Metabolite profiling of a fast neutron soybean mutant reveals an increased abundance of isoflavones. Food Chemistry. 71(26):9994-10003. https://doi.org/10.1021/acs.jafc.3c01493.
DOI: https://doi.org/10.1021/acs.jafc.3c01493

Interpretive Summary: Soybean seeds are a major source of vegetable protein and oil. Several biotechnology techniques were employed to improve soybean seed quality such as protein content. To make the best use of these mutated soybean seeds, a comprehensive biochemical characterization is required. In this study, we employed a non-targeted metabolic approach to investigate the effects of deleting 24 genes on the metabolome of a mutated soybean line, which exhibited 15% more seed protein content compared to the wild type. The results showed that the gene deletion altered carbon allocation, resulting in increased abundances of certain aspartate family metabolites that stores methionine in the mutant seeds. The deletion of the sucrose transporter and cell membrane-associated genes resulted in carbon partitioning towards sulfur-containing metabolites in the mutant seeds and added value to the soybean seed. The results from this study will assist scientists and breeders in developing value-added quality traits of soybeans.

Technical Abstract: Soybean (Glycine max [L.] Merr) seed is a valuable source of raw materials in the food, feed, and pharmaceutical industries. Using non-targeted metabolic profiling, we identified 718 of the metabolites in leaves and seeds of a fast neutron mediated soybean mutant known to have 24 genes deleted. This mutant, M92-220’(5R10C28Decfbar241aMN15) has 15% more seed protein compared to wild-type seed. Among the 559 metabolites identified in leaves and 629 identified in seed, 465 appeared both in seed and leaves. Mapping of the deleted genes and seed metabolites showed significant perturbation metabolic pathways involving glutamine, aspartate, and aromatic amino acids, as well as glycolytic and TCA pathways. The mutant seed showed a higher content of sulfur containing metabolites such as S-methylmethionine, methionine, and cysteine as compared to the wild-type seed. The deleted genes include sucrose transporter and cell membrane-associated genes. The deletions may alter carbon flow in the glycolytic and TCA pathways, resulting in increased abundance of sulfur-containing metabolites in the mutant seeds and added value to the soybean seed.