Evaluation of Physiological Functionalities and Anti-inflammatory Activity on <Emphasis Type="Italic">in vitro</Emphasis> Cultured Adventitious Root of <Emphasis Type="Italic">Platycodon grandiflorum</Emphasis>

This study was executed to evaluate the phenolic content, DPPH, ABTS radical scavenging rate, nitrite scavenging rate, and anti-inflammatory activity from in vitro cultured adventitious root extract of different Platycodon grandiflorum(PG) variety. Total polyphenol and flavonoid content showed the highest amount in adventitious root extract of tetraploid PG, and followed by green petal, double petal and diploid PG extract. The DPPH radical scavenging activity showed that the increase was proportional to the concentration, especially, the scavenging activity at a concentration of 10 mg mL^-1 was higher than 80%. The ABTS radical scavenging activity was not significantly different among the PG varieties at the concentration of 5 mg mL^-1 or more, and generally showed high scavenging activity. The nitrite scavenging activity was affected by pH, at pH of 1.2, the scavenging effect of all of the extracts tested observed higher than that of the other two pH ranges. The cytotoxicity of PG extract at various concentrations, the survival rate of RAW 264.7 cell was more than 90% at a concentration of 200 μg mL^-1 or less, and it was confirmed that the macrophage cell showed little toxicity. After PG extract pretreatment at 50, 100, and 200 μg mL^-1, LPS-treated experimental group significantly inhibited NO production in a dose-dependent manner. The dose-response trends followed quadratic regressions in all PG varieties. The PG extracts showed a considerable range of influence on cytokine secretion. The effect of adventitious root extracts of PG against inflammatory mediators TNF-α, IL-6 and IL-1β production showed the most significant anti-inflammatory activity.     

Cytogenetic Diversity of Korean Hexaploid Wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) with Simple Sequence Repeats (SSRs) by Fluorescence <Emphasis Type="Italic">In Situ</Emphasis> Hybridization

Chromosomes of Korean hexaploid wheat were investigated to compare the chromosomal karyotype for cytogenetic diversity. Chromosomal karyotyping was done with in situ hybridization using two types of simple sequence repeats (SSR)s, (AAG)₅ and (AAC)₅ labeled with tetramethyl-rhodamine-5-dUTP and fluorescein-12-dUPT as a fluorescence, respectively. The two SSRs as cytogenetic markers revealed that the cytogenetic characteristics of the wheat chromosomes were remarkably a B genome. In this study, the chromosomal karyotype of Keumkang, a Korean hexaploid wheat cultivar, was the A, B, and D genomes used as a cytogenetic reference. The expressed signals from the two SSRs showed a difference in the chromosomal karyotype of chromosome 1B among the Korean hexaploid wheat. The distribution pattern and the degree of condensation for the (AAG)₅ and (AAC)₅ signals on the short arm of chromosome 1B were different in the Korean hexaploid wheat shown in descending order: Keumkang > Joeun > Johan > Olgeuru. Olgeuru had a lower level of distribution and condensation for the two SSRs signals compared to the other Korean hexaploid wheat. In the A genome, chromosome 7A showed an unbalanced expression of the (AAG)₅ signal on the distal region of the short and long arms in several Korean hexaploid wheat while Joeun, a Korean hexaploid wheat, showed a definite (AAG)₅ signal on the distal region of each arm of chromosome 7A. Among the Korean hexaploid wheat, Shinmichal1, a Korean hexaploid waxy wheat, had a chromosome with a unique expression pattern for (AAG)₅ and (AAC)₅ compared the other Korean hexaploid wheat. Those cytogenetic differences identified in this study are useful as an indicator to improve the cytogenetic diversity in the Korean wheat breeding program.     

Effects of Nitrogen,Phosphorus and Potassium Fertilizers on Growth Characteristics of Two Species of Bellflower (Platycodon grandiflorum)

Journal of Crop Science and Biotechnology - Fertilization plays a vital role to enhance productivity in several medicinal plants, including Bellflower. A pot experiment was conducted in 2018 to...     

Genotypic Variation in Fatty Acids in Whole Grain Sesame (Fatty Acids in Whole Grain Sesame)

Journal of Crop Science and Biotechnology - Fatty acids (FAs) are important desirable compounds in oil crops. Here, we evaluated the amounts of 14 FAs in sesame grains using gas chromatography mass...     

Re-examination of the standard cultivation practices of rice in response to climate change in Korea

The impact of climate change has been simulated or estimated to bring about yield decline and quality deterioration of rice in Korea, a temperate country. To cope with these negative impacts, here we propose likely changes in the standard cultivation practices of rice in consideration of the current information on the progress/prediction of climate change and related physiological aspects of rice. Shifting grain-filling period could be a promising choice to optimize temperature for rice grain-filling, a crucial growth stage to productivity, hence providing rice plants with sufficient duration and solar radiation for the period. This choice, however, shortens days to flowering by the additive combined effects of high temperature by delayed transplanting, temperature rise itself by climate change, and accelerated phase change of rice by high temperature and short day-length. These combined effects may delay the time of transplanting in a great extent, hence reducing biomass accumulation of rice before flowering. In these conditions, recovering decreased biomass production is the key concern for rice productivity. This includes raising healthy seedlings by omitting the covering process, dense planting, and nutrient management to enhance plant’s uptake activity. Current standard water management, especially mid-term drainage and intermittent irrigation, would have more importance in the future since they mitigate methane emission from the paddy. Field monitoring for weeds and pests would be an important first step to identify newly developing or thriving species for establishing subsequent controlling strategies. Earlier weed control should be emphasized through adjusting time of herbicide application.     

Rapid screening and selection of low-caffeine-containing tea (Camellia sinensis) trees by a colorimetric method

A simple and rapid colorimetric method for the determination of caffeine has been developed. Tea tree lines from the Hadong region in South Korea differ widely in their caffeine contents and this colorimetric method facilitated an efficient screening strategy for the selection of low‐caffeine‐containing lines. A high correlation was observed between the values obtained with colorimetric and high‐performance liquid chromatographic analysis. Among the selected tree lines, the caffeine content for the lowest caffeine‐containing tea tree line (H‐19) was 178.35 μg/g dry weight basis, which was 61‐fold less productive than the highest caffeine‐producing tea tree line (H‐82). Caffeine contents of the selected tea tree lines remained similar during the corresponding collection periods. The colorimetric method is of great practical value in screening low‐caffeine‐containing tea trees.     

Protein Profiling from Hormone-Induced Tetraploid Roots in Platycodon grandiflorum

Journal of Crop Science and Biotechnology - The root of Platycodon grandiflorum is used as traditional oriental medicine in Asian countries since ancient times to treat bronchitis, tonsillitis,...     

Evaluation of waterlogging tolerance with the degree of foliar senescence at early vegetative stage of maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

Maize is highly susceptible to waterlogging, which is becoming one of worldwide abiotic threats in many agricultural areas. This study was evaluated to establish the screening method and to find tolerant maize genotypes. Six Korean maize inbred lines were subjected to waterlogging at V3 for 15 days using a big size pot with single maize plant (big pot method) and a box containing 31 maize plants at a time (box method). The degree of foliar senescence and the number of senescent leaves were better indicators for selecting waterlogging tolerant maize genotypes than SPAD value and plant height. The degree of foliar senescence revealed that KS124, KS140, and KS141 are tolerant, and KS85 is susceptible to waterlogging at the early growth stage. These responses of foliar senescence were in clear accordance with those of plant grain yield, which was supported by stress tolerance index for grain yield. The box method also showed the similar response of foliar senescence to the big pot method. Therefore, this box method based on foliar senescence may be simple and efficient for large-scale screening of maize germplasm against waterlogging stress. It was concluded that foliar senescence can be a good indicator for selecting tolerant maize genotypes against waterlogging at the early growth stage.     

What drives the labor share of income in South Korea? A regional analysis

This study takes a regional approach to analyzing what drives labor's share of income for South Korea over 2000–2014. First, we document empirically that changes in the labor share within a region are the dominant component of the change in the aggregate labor share of national income. To study the dynamic determinants of the labor share of income at the regional level, a panel vector autoregression (PVAR) model is estimated to examine how the regional labor share responds to innovations in an array of variables suggested by theoretical models. Consistent with theory, we confirm that technology, capital intensity and market concentration are the key variables explaining the labor share dynamics. Furthermore, we analyze the effects of trade openness and R&D expenditures on the regional labor share. Interestingly, we find that the labor share shows a different pattern of responses to the identified shocks depending upon the type of regions, that is, whether it is in the metropolitan or provincial areas. We also discuss the implications of our results for both theory and policy.