Soybean callus - a potential source of tocopherols

Authors: MURESAN, LILIANA - University Of Agricultural Sciences And Veterinary Medicine - Romania; CLAPA, DOINA - University Of Agricultural Sciences And Veterinary Medicine - Romania; RUSU, TEODO - University Of Agricultural Sciences And Veterinary Medicine - Romania; Wang, Thomas - Tom; Park, Jae

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2021
Publication Date: 11/25/2021
Citation: Muresan, L., Clapa, D., Rusu, T., Wang, T.Y., Park, J.B. 2021. Soybean callus - a potential source of tocopherols. Plants. 10:2571. https://doi.org/10.3390/plants10122571.
DOI: https://doi.org/10.3390/plants10122571

Interpretive Summary: Soybean [Glycine max (L. Merr.]is a great source of tocopherols with about 300 µg g-1/seed total tocopherols. In fact, tocopherols exist in four forms (i.e., a(alpha), ß(beta), (gamma) and d(delta) tocopherols. Among them, gamma tocopherol is found in higher concentrations (more than 60%) and a-tocopherol accounts for less than 10% of total tocopherols in soybean seeds. Despite the less presence, alpha-tocopherol is reported to have the most significant antioxidant activity among tocopherols. Therefore, dietary reference intake for vitamin E is currently based solely on a-tocopherol. For this reason, there are great research efforts to find a suitable/sustainable way to produce tocopherol, especially a-tocopherol. Recently, soybean callus was reported to be utilized in increasing the production of tocopherols in soybeans by accelerating the flow of biosynthesis with an increased total tocopherol content. Therefore, there is a possibility to use soybean callus as a sustainable source to produce tocopherol. However, despite the potential of soybean callus as a potential source of tocopherols, there is missing information about potential effects of commonly used herbicide uses on soybean callus production. Therefore, we investigated three aims; the production of soybean calli from soybeans cultivated under three different weed controls (without herbicide and with two variants of herbicide), the determination of the potential effects of weed control methods on tocopherol contents, and the usability of soybean callus as a suitable source of a-tocopherol (a-toco), (gamma-toco) tocopherol and d (delta-tocopherol (d-toco). The data in this study suggest that soybean callus can be used as a potential means to obtain tocopherols, although herbicide uses significantly influence both the in vitro callus production and the tocopherol callus content. This study provides new information about using soybean callus as a potential source of tocopherols.

Technical Abstract: In vitro cultures have been used as an effective means to achieve a high level of secondary metabolites in various plants including soy. In this study, the contents of alpha, gamma, and delta tocopherols were quantified in soybean callus, and their amounts were compared to those of soybeans cultivated using the conventional tillage system with three weed controls (respectively without herbicide and with two variants of herbicide). Soybean callus was produced using Murashige and Skoog 1962 (MS) medium supplemented with 0.1 mg / L 6-Benzylaminopurine (BAP) and 0. 1 mg / L Thidiazuron (TDZ). The highest amount of total tocopherol (13652.35 ± 1177.62 mg) was obtained from fresh callus from soybeans from the conventional tillage system with 2nd weed control (S-metolachlor 960 g / L, imazamox 40 g / L, and propaquizafop 100 g / L). Of the three analyzed tocopherols, the highest content was gamma-tocopherol, both in callus and soybeans. Furthermore, the data showed that herbicides used in soybean culture significantly influenced both the in vitro callus production and the tocopherol callus content (p<0.05). Altogether, soybean callus can be an important source of tocopherols, and herbicides significantly influence both the in vitro callus production and the tocopherol callus content.