GABA mediates NO/cGMP/GSK-3-induced isoflavone accumulation in soybean sprouts

The effects of glycogen synthase kinase-3 (GSK-3) on nitric oxide (NO)/guanosine 3',5'-cyclic monophosphate (cGMP)-activated gamma-aminobutiric acid (GABA) accumulation and the role of GABA in isoflavone biosynthesis in response to UV-B exposure in soybean sprouts were investigated. The sprouts were sprayed using donors and inhibitors of cGMP and NO as well as inhibitors of GSK-3 and GABA. It turned out that GSK-3, as a second messenger, mediated NO/cGMP/PKG-induced GABA accumulation by activating diamine oxidase (DAO) under UV-B treatment. GABA mediated NO/cGMP/PKG/GSK-3-stimulated the increment of gene and protein expression and activity of chalcone synthase (CHS) and isoflavone synthase (IFS), and consequently induced the elevation in isoflavone content. Overall, GABA mediates NO/cGMP/PKG/GSK-3-stimulated isoflavone production in response to UV-B exposure in soybean sprouts.

Automated summary

The study showed that GSK-3 mediated the accumulation of GABA induced by NO/cGMP/PKG through activation of DAO under UV-B treatment, and GABA further mediated the increase of CHS and IFS gene and protein expression and activity stimulated by NO/cGMP/PKG/GSK-3, leading to the elevation in isoflavone content.