Kyeong-Cheol Lee

Physiological Response and Growth Performance of Parasenecio firmus under Different Shading Treatments

This study was conducted to investigate the chlorophyll contents, photosynthetic characteristics, chlorophyll fluorescence, and growth performance of Parasenecio firmus under changing light environment. Parasenecio firmus was grown under non-treated (full sunlight) and three different shading conditions (88~93%, 65~75% and 45%~55% of full sunlight) for the experiment. Total chlorophyll content, photochemical efficiency (Fv/Fm), T/R ratio, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) were increased with increasing shading level, but decreased dark respiration. Therefore, light absorption and light utilization efficiency were improved under the low intensity light. Plants under 65~75% of full sunlight had best maximum photosynthetic rate and net apparent quantum yield in May. On the other hand, the non-treated plants had lower maximum photosynthetic rate, photochemical efficiency, and chlorophyll content than the treated ones. Parasenecio firmus considered to be a sciophyte, is fairly sensitive to high intensity light. If 88-93% of full sunlight lasts for a long period, photosynthetic capacity will be sharply decreased, though limiting light. These results suggest that growth of Parasenecio firmus adapted to 65~75% of full sunlight.

Antioxidant and anti-inflammatory activities of different solvent fractions from ethanol extract of Synurus deltoides (Aiton) Nakai leaves

Fractions of Synurus deltoides (Aiton) Nakai leaves showed excellent antioxidant and anti-inflammatory effects in a series of antioxidant and anti-inflammatory assays including total phenolic and flavonoid contents determination assay, DPPH free radical scavenging assay, reducing power assay, superoxide radical scavenging assay, nitrite scavenging assay, total antioxidant assay, DNA damage protection assay, MTT assay, nitric oxide (NO) production inhibition assay, and reverse transcription (RT)-PCR assay. The ethyl acetate fraction exhibited stronger antioxidant effects than other fractions in most of antioxidant assays such as DPPH assay, reducing power assay, superoxide radical scavenging assay, and nitrite scavenging assay. However, the dichloromethane fraction showed the strongest total antioxidant activity and NO production inhibitory activity. It was demonstrated that S. deltoides was valuable to be researched farther and application and fractions of S. deltoides had great potential to be a source of edible antioxidant and anti-inflammatory agents.

Comparison of Photosynthetic Responses in Allium microdictyon Prokh and Allium ochotense Prokh from Atmosphere-Leaf Vapor Pressure Deficit (VPD)

This study was conducted to investigate the effect of atmosphere-leaf vapor pressure deficit (VPD) in Allium microdictyon Prokh. and Allium ochotense Prokh. The vapor pressure deficit (VPD) was rapidly increased with increasing temperature and decreasing relative humidity. Taken as a whole, the stomatal transpiration reaction was slightly late with increading of VPD. Maximum photosynthetic rate at high-VPD condition was 5.98 in Allium microdictyon, which was a little lower than 6.59 in Allium ochotense, respectively. After 2 p.m, stomatal transpiration of Allium microdictyon at the high VPD condition were rapidly decreased. Ci/Ca began to decline sharply at 8 a.m and showed the lowest value at 2 p.m, The results showed that Ci/Ca decreased with being used in the mesophyll intercellular space for photosynthesis. In high VPD condition, The water potential values showed the highest at 5 a.m, and the lowest at 1 p.m in high VPD condition. The water saturation deficits (WSD) in high VPD condition showed about 1.5 times higher than in low VPD condition. The results indicated that physiological activities in Allium microdictyon is more limited from high VPD conditions.