The study was to evaluate regeneration, mineral nutrients, and antioxidative activities of adventitious shoot in tuberous root radish (Raphanus sativus L.) grown under light and dark conditions in a controlled growth chamber. Small pieces of top of root radish, including adventitious shoots, were detached from mother radish roots (1 st cut) and grown for 22 days (22 DAC 1), which then re-cut (2 nd cut) and re-grown for 23 days (23 DAC 2). Fresh weight was heavier on plants grown under the dark condition (6.2 g) at 22 DAC 1 compared to the light condition (5.2 g) but was not significantly different between the treatment conditions at 23 DAC 2. Shoot length was significantly extended by the dark condition during the experimental period. Leaf concentrations of Ca, Mg, Na, and Mn were significantly increased by the light condition, with high leaf concentrations of Fe, Zn, and Cu observed on the dark condition. Proline of total amino acids was highly increased by the light condition (126.8 mg g-1) compared to dark condition (16.3 mg g-1), but other total amino acid concentrations were varied between the treatment conditions. Fructose and sucrose were increased by dark and light conditions, respectively. Dark condition reduced scavenging activity (9.7%), total phenolic (12.2 mg g-1) and flavonoid compounds (0.05 mg g-1) compared to the light condition (scavenging activity; 49.3%, total phenolic 43.8 mg g-1 and flavonoid compounds; 0.21 mg g-1) at 22 DAC 1 , which was also observed at 23 DAC 2. Excised adventitious shoot of radish grown under the dark condition could be useful propagation technique for convenient consumption at all times and the physicochemical values to some degree.

The aim of this study was to identify major anti-inflammatory compounds in Alopecurus aequalis Sobol. (A. aequalis). The ethanol extract and the hexane-, dichloromethane-, ethyl acetate- and n-butanol-soluble fractions derived from A. aequalis were evaluated in order to determine their inhibitory effects on nitric oxide (NO) production in RAW 264.7 cells stimulated with lipopolysaccharide (LPS). The ethanol extract decreased NO production in a dose-dependent manner without any evidence of cytotoxicity at a concentration range of 0-200 µg/ml. The ethyl acetate soluble fraction was the most potent among the four soluble fractions. A compound was isolated by reversed-phase high-performance liquid chromatography from the ethyl acetate soluble fraction and this was identified to be tricin. Tricin inhibited the LPS-induced NO production in a dose-dependent manner without any evidence of cytotoxity at a concentration range of 1-100 µg/ml. Tricin also inhibited the LPS-induced production of prostaglandin E2. Western blot analysis indicated that tricin decreased the LPS-induced increase in the protein levels of inducible NO synthase and cyclooxygenase. In addition, tricin suppressed the production of intracellular reactive oxygen species in the LPS-stimulated RAW 264.7 cells, as measured by flow cytometry. Taken together, our results clearly indicate that tricin is a major functional anti-inflammatory compound which can be isolated from A. aequalis extracts.

No abstract

Transgenic rice (Oryza sativa L. ‘Dongjin’) lines, AP37 and MX, overexpressing Arabidopsis thaliana and Myxococcus xanthus protoporphyrinogen oxidase (PPO), respectively, were examined for their physiological responses and tolerance mechanism to drought stress. AP37 and MX lines were previously confirmed to be resistant to PPO inhibitors. Transgenic AP37 and MX plants showed significantly improved drought tolerance, as indicated by higher water content, lower leaf injury, less oxidative damage, and more favorable redox balance compared to wild‐type (WT) plants. The magnesium‐protoporphyrin IX (Mg‐Proto IX) content of WT and the transgenic lines did not vary significantly with the drought treatments, but MX lines had higher Mg‐Proto IX methyl ester (ME) content after 90 h of drought treatment compared to WT and AP37. In addition, the expression of most genes involved in porphyrin biosynthesis, particularly in the chlorophyll branch, such as glutamyl‐tRNA reductase, glutamate‐1‐semialdehyde aminotransferase, protoporphyrinogen oxidase 1, Fe‐chelatase2, H‐subunit of Mg‐chelatase, and I‐subunit of Mg‐chelatase, was up‐regulated in the transgenic plants, and this up‐regulation was higher in AP37 than in MX. Overall, the AP37 transgenic line was found to show better drought tolerance than the MX transgenic line.

In this study, we measured the expression of genes related to the phenylpropanoid pathway and ascorbate oxidation by qRT-PCR to explore the mechanism of nutraceutical compounds enhancement in pak choi during stress treatments. The expression of most phenylpropanoid biosynthesis related genes (PAL, C4H, CHS, CHI, F3H1, DFR, and ANS1) was up-regulated in plants treated with NaCl, solar salt, and UV-B radiation, compared with the untreated controls under both white light and light emitting diode illumination. Moreover, CHS and ANS1 were expressed at levels 15 and 95 times higher than the untreated control. The expression of the ascorbate oxidation related gene tAPX was also up-regulated in the NaCl and UV-B treated samples compared with the control under both light conditions. By comparison, the expression of APX1 was down-regulated during the stress treatment under both light conditions. Total chlorophyll and total carotenoid contents were unaffected by the stress treatments, and there was no significant difference in the maximum quantum yield (Fv/Fm) between the stress treatments and the untreated controls. These results suggest that the expression of genes involved in phenylpropanoid biosynthesis and ascorbate oxidation correlates with the previously reported enhanced production of phenolic compounds in pak choi plants subjected to stress treatments.