Buckwheat (Fagopyrum esculentum), which is a traditional Korean crop, has been known as a health food due to its rich nutrition. This study was conducted to evaluate the change in flavonoid content of flowers and seeds during post-flowering growth of Korean tartary buckwheat variety ‘Hwanggeummiso’, with the aim of providing basic data for the development of functional food and feed additive. Tartary buckwheat took 69 and 99 days from the sowing date to reach the flowering and maturity stages, respectively. As a result of examining the flavonoid components of each part of tartary buckwheat, chlorogenic acid, rutin, and isoquercitrin of flowers increased from the flowering period on 22 May (0 days after flowering) to 42 days after flowering, while quercetin increased until 21 days after flowering and then decreased thereafter. In seeds, chlorogenic acid, rutin, and isoquercitrin were most abundant at the time of seed-bearing on 14 days after flowering, and showed a decreasing tendency thereafter. On the other hand, quercetin showed a tendency to increase until 21 days after flowering and then decrease. Overall, the flavonoid content was higher in flowers than in seeds, with rutin being particularly prominent. Based on this, the possibility as food materials and feed additives was confirmed using buckwheat produced in Korea.

Tartary buckwheat has established itself as a functional food source because of its basic nutrition and phenolic compound contents, such as dietary fiber (DF) and rutin (RU). However, little information has been obtained concerning the comparative effects of DF and RU on the in vitro and in vivo glucose responses of tartary buckwheat flour. Moreover, the relationship between the flour’s in vitro starch digestibility and its components’ blood glucose response is not well-known. This study found that DF and RU reduced rapidly digestible starch (RDS) by 37.32→33.88% and 41.71→30.28%, whereas they increased resistant starch (RS) by 30.47→31.46% and 28.41→36.78%, respectively. Furthermore, RU had a lower glycemic index (GI) compared to DF. The regression equation for the in vitro and in vivo data from RU exhibited positive correlation (R 2 = 0.99); however, DF did not display positive correlation, which indicates that the in vitro and in vivo GI mechanisms by DF and RU are different.

본 연구에서는 쓴메밀 74개 유전자원의 종자 표현형 및 화학 형과 관련된 8개 주요형질을 평가하였으며, 그 결과를 바탕으로 주성분분석 및 군집분석을 수행하였다. 또한 rutin 고함유 자원 등 기능성 쓴메밀 육성재료로 활용가능한 유망 유전자원을 선발하였다. 쓴메밀 유전자원의 종자크기는 일반메밀보다 작은 평균 5.2 × 3.4 ㎜였으며, 종피색은 흑갈색이 45.9%로 가장 많았다. 종자모양은 달갈형과 타원형이 주를 이루었다. 쓴메밀 종자의 유용성분 평균 함량은 rutin이 1,393 ㎎/100 g DW였다. Flavonoid 함량 범위는 253-2,669 ㎎/100 g이었으며, polyphenol 함량 범위는 209-1,823 ㎎/100 g 으로 나타냈다. 쓴메밀 유전자원의 주성분 분석 결과, 제3주성분까지 적용하였을 때 전체 분산의 68.55%를 설명할 수 있었다. 제1주성분에는 rutin, flavonoid 및 polyphenol, 제2주성분에서는 종자길이, 제3주성분에서는 종자폭의 비중이 큰 것으로 나타났다. 이를 바탕으로 5개의 군집으로 구분할 수 있었으며, 유전자원을 구분하는 가장 중요한 형질로는 rutin, flavonoid 및 polyphenol이었다. 쓴메밀 유전 자원 중 5개 자원(HLB1004, HLB1005, HLB1007, HLB1009, HLB1013)이 높은 rutin 함량을 보였으며, 이러한 유용자원들은 향후 기능성 육종소재 개발에 효과적으로 활용가능할 것으로 기대된다.

Background : Tropospheric ozone (O3) is a secondary air pollutant that negatively affects numerous agricultural crop and forest. The tropospheric ozone is constantly increasing due to fossil fuel air pollutants. Here, we study the response of tartary buckwheat to ozone gas includes physiological and biochemical changes such as change in gene expression and metabolism. Methods and Results : Tartary buckwheat plants have green stems and leaves under normal conditions, while the plants exposed to the ozone have red stems and reddish green leaves. The expression of most flavonoid biosynthetic genes were significantly upregulated in ozone-treated buckwheat plants, exceting the expression of FtF3’H2. The contents of two anthocyanins, cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside, were significantly increased by ozone treatment. From the metabolic profiling based on the GC-TOF-MS analysis, we identified the effect of ozone on thirty-five metabolites, including sugars, amino acids, and organic acids. Most of the metabolites result in significantly decreased or nearly remain unchanged in the ozone-treated plants compared with untreated plants, excepting alanine, proline, tryptophan, sucrose, and raffinose. To identify the effect of ozone on the leaf, we analyzed the epidermal cells on the leaf surface by scanning electron microscopy. Interestingly, amount of epidermal cells were partially destructed in ozone-treated plants. Conclusion : By analyzing both primary and secondary metabolites of tartary buchwheat without or with ozone, we identified that ozone affects the modulation of the metabolites as well as gene expression in tartary buchwheat.

The aim of this study was to determine the suitability of surfactant to extract higher phenolic compound, flavonoid and antioxidant activity from Tartary buckwheat and evaluate the potentiality of surfactant as a screening agent for breeding purpose. Primarily, we employed two types of surfactant (Hydrophilic: Tween 20 and Lipophilic: Span 80) to select the suitable surfactant agent for the extraction of optimum bioactive compounds. Between two surfactants, Tween 20 showed highest efficiency at 4 mM concentration to extract total phenolic content (TP), total flavonoid (TF) and antioxidant activity (AA). Tween 20 at 4 mM concentration was fixed for further analysis along with hot water (90℃) treatment as a control. In our findings, highest TP (118 ㎎/g), TF (38 ㎎/g) and AA (76%) was achieved in KW21 and KW22 among the fifteen accessions of Tartary buckwheat. In other way, TP, TF and AA was 200%, 120% and 110% higher in surfactant formulation compared with control treatment, respectively.

Background : Buckwheat (Fagopyrum spp.) is an annual crop belonging to the polygonaceae family and cultivated in most of Asian and European countries. Nowadays, many people take interest in the utilization of buckwheat seed because of its high nutritional and pharmaceutical values. Especially, tartary buckwheat is drawing attention for its high rutin content, which is beneficial to health. Methods and Results :　Tartary buckwheat sprout (TBS) was powdered and two grams of powder was mixed with 4 ㎖ H2O in a glass petri disc (100 x 20 ㎜) and exposed to far infrared irradiation (FIR) at different temperature (80, 100, 120, 140, 160℃) for an hour each. Further, the FIR treated powdered sprout samples were suspended in 200 ㎖ of 80% ethanol (v/v) and kept overnight in a shaker at room temperature. The extracts were filtered through Advantec 5B Tokyo Roshi Kaisha Ltd., Japan and dried using a vacuum rotatory evaporator (EYLA N-1000, Tokyo, Japan) in a 40℃ water bath. Dried samples were weighed and kept at 4℃ for further analysis. Conclusion : Total polyphenol was evaluated by Folin-Ciocalteau assay and total flavonoid by aluminum nitrate colorimetric assay, while antioxidant properties were evaluated based on DPPH free radical scavenging activity, metal chelating property and total antioxidant capacity. This study showed that FIR treatment to TBS caused a decrease in total antioxidant capacity and metal chelation property. However, there was a slight increase in total polyphenol and total flavonoid content from 80 to 120℃. Similarly, DPPH free radical scavenging activity also increased in the same way as TP and TF in TBS. The HPLC result revealed that quercetin production was directly proportional to temperature, and the production (average 14.87 ㎎/g dw) of quercetin was highest at 120℃ (an hour’s treatment), which was 13.54 times higher than the control in TBS.

This experiment was conducted to investigate the endophytic bacterium Herbaspirillum spp effect on seed germination and sprout growth of tartary buckwheat. Inoculant concentration (%v/v) and seed soaking time were applied 10, 20 and 40% and 0, 4, 8, 12 hour, respectively. The experiment was carried out in a growth chamber maintained temperature at 20, 25 and 30ºC without light for 7 days. Results showed that, 10 to 20% (v/v) inoculant concentration by 4 to 8 h seed soaking time at 20°C temperature increased seed vigor rate and total seed germination rate 80-95% and 90-100%, respectively. On the other and, seed inoculation with Herbaspirillum spp. increased hypocotyl length (13-15 ㎝), root length (8-11 ㎝), total fresh weight (135-296 g) and total dry weight (7-10 g), compared to control. It is indicated that sprouts growth and yield depends on inoculation concentrations, seed soaking time and temperature. Therefore, it would be suggested that seed inoculation with Herbaspirillum spp. at concentration of 10 to 20% (v/v), soaking time 4 to 8 h and temperature 20°C promote seed germinations and sprout growth rate of tartary buckwheat.

Background : Plants live in restricted spaces that are constantly exposed to various environmental stresses. Under these stressful conditions, plants lead to biosynthesize specialized metabolites to adapt to environmental stresses. Here we investigate the effects of cold on the metabolome of tartaty buckwheat, focusing the flavonoid biosynthetic pathway. Methods and Results : From the metabolic profiling based on the GC-TOF-MS analysis, we identified the effect of cold on forty-four metabolites, including sugars, amino acids, and organic acids. Most of sugars and sugar derivatives remain nearly unchanged or slightly decreased in the plants grown at 25 ºC, whereas sugar and sugar derivative contents of cold-treated plants significantly increased, excepting galactose. Some of amino acid and amino acid derivatives contents decrease in cold-treated plants, whereas organic acid derived from tricarboxylic acid (TCA) cycle were increased the cold-treated plants compared with the plants grown at 25 ºC. Particularly, the contents of two anthocyanins, cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside, were significantly increased by cold treatment. Proanthocyanidins such as epicatechin and catechin were also significantly affected by cold. The expression of most flavonoid biosynthetic genes were significantly upregulated in cold-treated buckwheat seedling. Among the flavonoid biosynthetic genes, the expression of FtANS was notably upregulated in response to cold. Conclusion : By analyzing both primary metabolites and secondary metabolites of tartary buchwheat without or with cold, we showed that cold play a critical role in the modulation of the primary metabolites and flavonoid synthesis pathway in tartary buchwheat. Particularly, anthocyanin and proanthocyanidin biosynthetic pathways are strongly up-regulated in response to cold.