No abstract

Xylem sap plays a major role in long‐distance transport of water, nutrients, and metabolites. However, there is little information on the behavior of metabolites in mineral‐deficient xylem sap. For this reason, the time‐dependent changes in selected metabolites (amino acids, organic acids, and soluble sugars) from tomato xylem sap in response to nitrogen (N), phosphorus (P), or potassium (K)‐deficient condition were investigated. Tomato plants (Solanum lycopersicum L.) were grown hydroponically in liquid culture under three different mineral regimes: N‐deficient [0.5 mM Ca(NO3)2 and 0.5 mM KNO3], P‐deficient (0.05 mM KH2PO4), and K‐deficient (0.5 mM KNO3), respectively. Xylem sap was collected at 10:00 am after 1, 5, 15, and 30 d, and the selected metabolites were analyzed with liquid chromatography. All N, P, or K deficiencies led to a substantial increase in metabolites in the xylem sap. The predominant amino acid in the xylem sap was glutamine and, interestingly, all mineral deficiencies resulted in a substantial amount of γ‐aminobutyric acid (GABA). Additionally, organic acids (citrate and malate) and soluble sugars were strongly increased in all mineral deficiencies, and, in particular, the level of shikimate was greatly affected by N deficiency. Based on these data, it is necessary to clearly elucidate an unknown event taking place in xylem loading in a variety of environmental impacts, and we are now studying to expand our knowledge on metabolic and proteomic responses using GC‐MS and LC‐MS.

Dietary habits and gut microbiota play an essential role in non-alcoholic fatty liver disease (NAFLD) and related factors such as insulin resistance and de novo lipogenesis. In this study, we investigated the protective effects of Bacteroides uniformis CBA7346, isolated from the gut of healthy Koreans, on mice with high-fat diet (HFD)-induced NAFLD. Administration of B. uniformis CBA7346 reduced body and liver weight gain, serum alanine aminotransferase and aspartate aminotransferase levels, liver steatosis, and liver triglyceride levels in mice on an HFD; the strain also decreased homeostatic model assessment for insulin resistance values, as well as serum cholesterol, triglyceride, lipopolysaccharide, leptin, and adiponectin levels in mice on an HFD. Moreover, B. uniformis CBA7346 controlled fatty liver disease by attenuating steatosis and inflammation and regulating de novo lipogenesis-related proteins in mice on an HFD. Taken together, these findings suggest that B. uniformis CBA7346 ameliorates HFD-induced NAFLD by reducing insulin resistance and regulating de novo lipogenesis in obese mice.

: An estimation of the requirement of minerals based on growth stage and cropping pattern is very important for greenhouse zucchini. This study was performed at farmer's field which was applied with a fertigation system and a semi-forcing cultivation from Feb. to July in 2014, and nitrogen levels were set up with x0.5, x0.75, x1.0 and x1.5 of the NO3-N-based soil-testing recommendation for zucchini cultivation. Top dressing of nitrogen (basal : top = 4 : 6) and potassium (basal : top = 3 : 7) was applied with an interval of every two weeks from two and six weeks after transplanting, respectively, and phosphorus was totally supplied with basal dressing. The nitrogen uptake was the order of x1.0, x0.75, x1.5 and x0.5, phosphorus, x1.0, x0.75, x0.5 and x1.5, and potassium, x0.75, x1.0, x1.5 and x0.5. From these results, it was suggested that highest mineral uptake could be reached between x0.75 and x1.0 of the NO3-N-based soil-testing recommendation. In conclusion, nutrient management based on the growth stage was proven to be better method for favorable growth and yield of zucchini.

Curcuma longa L. (turmeric) has been used as a functional food material, but other parts of it such as leaves are wasted as a byproduct. This work concentrated on developing turmeric leaves as a functional food material by establishing its optimal extraction condition. Response surface methodology was applied to optimize turmeric leaf extraction conditions. Turmeric leaves were pulled out with water and ethanol (10, 30, and 50%). Then, total phenolic compound content, total flavonoid content, and radical-scavenging activity of each extract were quantified to confirm the optimal extracting solvent. According to the results, water was the most efficient solvent to extract antioxidant contents such as total phenolic compounds (3.65 ± 0.02 mg GAE/g) and flavonoids (4.99 ± 0.17 mg QCE/g) content. Radical-scavenging activity was also higher in water extract compared with others such as DPPH (51.10 ± 2.29%), H2O2 (25.39 ± 2.69%), and ABTS (91.08 ± 0.15%). Central composite design was applied to confirm the effect of independent variables such as temperature (X1) and time (X2) to the yield (Y1). After conducting experiments, the extraction condition was established as 150 min with 1 : 25 ratio at 85°C with a 15.58% yield. Proximate compositions of the extract were determined to suggest background data for further research. In conclusion, this study confirmed the antioxidant property of turmeric leaves and developed the optimal extraction condition of the leaves to promote its application in food industry as a new food source.