Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
DAIZ Inc., 3-14-3 Minami-kumamoto, Chuo-ku, Kumamoto 860-0812, Japan.
J Agric Food Chem. 2021 Jun 30;69(25):7057-7063. doi: 10.1021/acs.jafc.1c02261. Epub 2021 Jun 21.
Apart from the physiological functions of soybean phytoalexins, the production sites in soybeans remain unknown. In this study, the dynamic production of phytoalexins, glyceollins, in germinating soybeans inoculated with was visually investigated using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging. During a 3-day sensitization using a fungus, glyceollins I-III were produced in germinating soybeans (from 0.03 mg/g for glyceollin III to 0.96 mg/g for glyceollin I). Imaging analysis provided visual evidence that glyceollins were produced only in the regions of seed coat and germinated root of the soybeans, while no production was observed in other regions, including the cotyledons. In contrast, their precursor, isoflavone, was distributed throughout the soybean. The evidence that the inoculation of the inactivated fungi also caused glyceollin production at the seed coat led us to speculate that glyceollins could be produced in the region of soybean attached to the fungus body.
除了大豆植物抗毒素的生理功能外，其在大豆中的产生部位仍不清楚。在这项研究中，利用基质辅助激光解吸/电离质谱成像（MALDI-MS 成像）直观地研究了接种后发芽大豆中植物抗毒素（glyceollins）的动态产生。在真菌致敏的 3 天过程中，发芽大豆（从 glyceollin III 的 0.03 mg/g 到 glyceollin I 的 0.96 mg/g）中产生了 glyceollin I-III。成像分析提供了直观的证据，表明 glyceollins 仅在大豆种皮和发芽根的区域产生，而在其他区域（包括子叶）则没有产生。相比之下，它们的前体异黄酮则分布在整个大豆中。接种失活真菌也会导致种皮产生 glyceollin 的证据，使我们推测 glyceollins 可能在附着真菌体的大豆区域产生。
