Project description:Fagopyrum cymosum is considered as most probable wild ancestor of cultivated buckwheat. However, the evolutionary route from F. cymosum to F. esculentum remains to be deciphered. We hypothesized that a hybrid species exists in natural habitats between diploid F. cymosum and F. esculentum. The aim of this research was to determine the phylogenetic position of F. esculentum ssp. ancestrale and to provide new thoughts on buckwheat evolution. Different methodologies including evaluation of morphological traits, determination of secondary metabolites, fluorescence in situ hybridization (FISH), comparative chloroplast genomics, and molecular markers were deployed to determine the phylogenetic relationship of F. esculentum ssp. ancestrale with F. cymosum and F. esculentum. The ambiguity observed in morphological pattern of genetic variation in three species revealed that F. esculentum ssp. ancestrale is closely related to F. cymosum and F. esculentum. Flavonoid analysis revealed that F. esculentum ssp. ancestrale is closely related to F. esculentum. Comparative chloroplast genome analysis further supported the close proximity of F. esculentum ssp. ancestrale with F. esculentum. Additionally, molecular marker analysis revealed that F. esculentum ssp. ancestrale exhibits co-dominance with the bands amplified by F. cymosum and F. esculentum. These finding provided supporting evidence in favor of the hypothesis that F. esculentum ssp. ancestrale is a hybrid species between F. cymosum to F. esculentum, which was probably originated by spontaneous hybridization under natural conditions.
Project description:A homogeneous preparation of metalloproteinase, purified 1000-fold, was obtained from buckwheat (Fagopyrum esculentum) seeds. The Mr of the enzyme, determined by SDS/PAGE, was 34,000 (it was 39,000 by gel chromatography). Its pH optimum was 8.0-8.2 with 13 S globulin, from buckwheat seeds, as substrate. Atomic-absorption spectroscopy revealed the presence of one Zn2+ ion per enzyme molecule. The enzyme was completely inhibited by EDTA (1 mM), zincone (1 mM) and 1, 10-phenanthroline (1 mM). The metalloproteinase performed limited proteolysis of the following seed storage proteins: 13 S globulin from buckwheat seeds and 11 S globulin from soybean (Glycine max) seeds. It hydrolysed three peptide bonds formed by the amino groups of Leu15, Tyr16 and Phe25 in the oxidized B-chain of insulin. In its main properties the enzyme is similar to metalloproteinases of animal and bacterial origin.