Effects of NaCl Treatment on Flavonoid Biosynthesis and Antioxidant System During Buckwheat Germination.

Exposure to abiotic stresses commonly stimulates the production of secondary metabolites in plants, and flavonoids represent a major class of these bioactive compounds. NaCl effects on antioxidant system treatment and flavonoid production in buckwheat sprouts was examined in this study using buckwheat as the raw material. In order to clarify the regulatory function of NaCl in these physiological processes, the changes in pertinent indices of buckwheat sprouts exposed to the control and NaCl treatments were studied. The results indicated that at three days old, the sprouts subjected to 80 mM NaCl treatment exhibited the highest total flavonoid content. The significant increase in enzyme activity (cinnamate 4-hydroxylase and 4-coumaroyl-CoA ligase, etc.) responsible for flavonoid biosynthesis provides strong evidence for this conclusion. The antioxidant system in buckwheat was activated by NaCl treatment, as evidenced by the dramatically increased antioxidant enzyme activities and the relative levels of expression of their respective genes compared to the control group. Levels of malondialdehyde and hydrogen peroxide were markedly higher than those in the control group, indicating that NaCl treatment inhibited the growth of buckwheat sprouts. This study not only reveals the mechanisms underlying buckwheat's response to NaCl stress but also lays a theoretical foundation for developing functional foods enriched with flavonoid-rich buckwheat sprouts.