Abstract:In order to investigate the influence of environmental stress on flavonoid metabolism and the molecular mechanisms underlying this response, the effects of salt (NaCl), drought (PEG-6000), and UV-B radiation on the contents of total flavonoids during florescence of Fagopyrum tataricum (Chuanqiao No.3) were examined. Treatments with all the three stress resulted in an increase in the total amount of flavonoids in roots, stems, leaves, and flowers by different degrees. Under NaCl and PEG-6000 treatments, the total flavonoids in all of these tissues were increased, while the highest value reached 160.0 mg·g-1 in leaves at 12 hours in NaCl stress. Besides, the leaves and flowers were more stress-sensitive than other tissues by PEG-6000 treatment. The total contents of flavonoids were also increased in roots, stems and leaves by UV-B stress and it went up to the highest level in leaves, while decreased evidently in flowers. Further study by real-time PCR revealed that changes in gene expression of CHI, F3H, FLS and FLS1 were consistent with that of the total flavonoids, suggesting these genes might play an important role in the adaptation of Fagopyrum tataricum to environmental stresses during florescence. Our results will provide new clues for tartary buckwheat breeding through transgenesis and have great potential for agricultural applications.