Changes in Rutin Concentration and Flavonol-3-glucosidase (Rutin Degrading Enzyme) Activity on Seedling Gowth in Tartary Buckwheat (Fagopyrum tataricum)

Abstract

To investigate physiological roles of rutin and flavonol-3-glucosidase (f3g) during cotyledon growth in tartary buckwheat, changes in rutin concentration and f3g activities were measured. The rutin concentration gradually increased just after germination (about 75 mg/g.d.w. in mature cotyledon). Most part of rutin was distributed in epidermis of cotyledon, where proanthocyanidins (condensed tannin) was also distributed. These results suggest that rutin play a role in UV screening. Most part of f3g was distributed in testa, which was stick to cotyledon until 4 DAG. The f3g, which should eluted from testa was also presented on a surface of cotyledon. It indicates that rutin in epidermis would hydrolyzed by f3g on surface of testa. It was recently reported that an anti-fungal compound is formed by oxidation of quercetin (hydrolyzed product of rutin). These results indicate that rutin and f3g may be related to enhancement of the defense system when cotyledon was injured.