- KOREAN
- P-ISSN2287-8327
- E-ISSN2288-1220
- SCOPUS, KCI
ISSN : 2287-8327
Vol.41 No.9
Abstract
Background: Loading of excess nutrient via bioremediation of polluted sediment to overlying water could trigger anoxia and eutrophication in coastal area. The aim of this research was to understand the changes of overlying water features such as dissolved oxygen (DO); pH; oxidation reduction potential (ORP); chlorophyll-a (Chl-a); and nitrogen nutrients ammonia (N-NH4 +), nitrate (N-NO3 −), and nitrite (N-NO2 −) when the sediment was not treated (control) and treated by calcium peroxide for 5 weeks. Methods: The water samples were analyzed for measuring physical and chemical properties along with the sediment analyzed by polymerase chain reaction (PCR) including denaturing gradient gel electrophoresis (DGGE) for identifying the phylogenetic affiliation of microbial communities. Results: Results showed that due to the addition of calcium peroxide in sediment, the overlying water exposed the rise of dissolve oxygen, pH, and ORP than control. Among the nitrogen nutrients, ammonia inhibition was higher in calcium peroxide treatment than control but in case of nitrate inhibition, it was reversed than control. Chlorophyll-a was declined in treatment column water by 30% where it was 20% in control column water. Actibacter and Salegentibacter group were detectable in the calcium-peroxide-treated sediment; in contrary, no detectable community ware found in control sediment. Both phylogenetic groups are closely related to marine microflora. Conclusions: This study emphasizes the importance of calcium peroxide as an oxygen release material. Interaction with peroxide proved to be enhancing the formation of microbial community that are beneficial for biodegradation and spontaneity of nutrient attenuation into overlying water.
Abstract
Background: The aim of this study was to examine the resource allocation among the organs and the leaf morphology of Polygonatum humile. The data were collected from June 2014 to May 2015 in a natural P. humile stand of a temperate forest gap. Results: The dry weight of new rhizome (R0) sharply decreased to the time of new shoot sprouting in next year and was constant for 2 ~ 3 years. However, dry weight of root on R0 increased to the end of growth season and, thereafter, decreased slowly along the time elapsed. The correlation coefficients between the rhizome and the leaf sizes were 0.5 for the last year’s rhizome (R1) and 0.6 for R0 and were significant at 0.1% level for R0. The increase of one leaf a plant led to increase of the total leaf area, total leaf weight, and stem length. Moreover, the organ sizes’ differences between two plants of the one leaf difference were almost significant at 1% level. In 11-leaf plant, the leaf length/width ratio and specific lea area increased to the second, relative leaf area to the fourth and relative leaf dry weight to the fifth, and thereafter, decreased to the last leaf. The differences in the values of these four parameters between two leaves on a stem were almost significant at 5% level. Conclusion: P. humile examined showed the close relationships between the last year’s rhizome or this year’s one and the shoot system (leaf and stem) sizes. The leaf number a shoot greatly influenced specific leaf area. P. humile’s leaf might showed diverse morphology with leaf rank on a stem in a forest gap environment.
Abstract
Background: The aim of this study was to clarify the relationship between the sexual reproduction and the resource allocation in a natural Polygonatum humile population grown in a temperate mixed forest gap. For this aim, the plant size, the node which flower was formed, the fruiting rate, and the dry weight of each organ were monitored from June 2014 to August 2015. Results: Firstly, in 3–13-leaf plants, plants with leaves ≤ 8 did not have flowers and in plants with over 9 leaves the flowering rate increased with the number of leaves. Among plants with the same number of leaves, the total leaf area and dry weight of flowering plants were larger than those of non-flowering plants. The minimum leaf area and dry weight of flowering plants were 100 cm2 and 200 mg, respectively. Secondary, the flowers were formed at the 3rd~8th nodes, and the flowering rate was highest at the 5th node. Thirdly, cumulative values of leaf properties from the last leaf (the top leaf on a stem) to the same leaf rank were greater in a plant with a reproductive organ than in a plant without a reproductive organ. Fourthly, fruit set was 6.1% and faithful fruit was 2.6% of total flowers. Biomasses of new rhizomes produced per milligram dry weight of leaf were 0.397 ± 190 mg in plants that set fruit and 0.520 ± 0.263 mg in plants that did not, and the difference between the 2 plant groups was significant at the 0.1% level. Conclusions: P. humile showed that the 1st flower formed on the 3rd node from the shoot’s base. And P. humile showed the minimum plant size needed in fruiting, and fruiting restricted the growth of new rhizomes. However, the fruiting rate was very low. Thus, it was thought that the low fruiting rate caused more energy to invest in the rhizomes, leading to a longer rhizome. A longer rhizome was thought to be more advantageous than a short one to avoid the shading.
Abstract
Background: Over the years, pine pollens have been excluded as an allergen due to its relatively large size, low protein content, and waxy hydrophobic layer, despite their abundance. However, recent studies suggest the possibilities of pine pollens being allergens, and it has been reported that allergy symptoms were highly prevalent in areas with considerably large pine forests and high possibility of exposure to the pollen. Therefore, we conducted a comparative analysis of the allergenicities of the pollens from the dominant species of Korean pines, red pine (Pinus densiflora), black pine (Pinus thunbergii), and pitch pine (Pinus rigida), in mice. Methods: The protein composition of the pollens from the three pine species was compared via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The pine pollens and proteins extracted from the pollens were introduced to BALB/c mice by nasal inhalation and application to exposed skin and the IgE produced by the mice were extracted from blood and analyzed via ELISA. Results: SDS-PAGE showed differing protein compositions of the pollens of the three pine species. Analysis of blood IgE compositions showed a similar amount of IgE produced when pollens were applied to skin. In contrast, when mice inhaled the pollens, P. densiflora was shown to induce significantly more IgE production than those of the other two species. Conclusions: The experimental results demonstrate that the pollens of all three South Korean pine species induce IgE production, and this production was more pronounced when the pollens were inhaled than when they were applied to the skin. Of the three species, the pollen of P. densiflora was found to induce the highest level of IgE production.
Abstract
Background: Soil microorganisms play key roles in nutrient cycling and are distributed throughout the soil profile. Currently, there is little information about the characteristics of the microbial communities along the soil depth because most studies focus on microorganisms inhabiting the soil surface. To better understand the functions and composition of microbial communities and the biogeochemical factors that shape them at different soil depths, we analyzed microbial activities and bacterial and fungal community composition in soils up to a 120 cm depth at a fallow field located in central Korea. To examine the vertical difference of microbial activities and community composition, β-1,4-glucosidase, cellobiohydrolase, β-1,4-xylosidase, β-1,4-N-acetylglucosaminidase, and acid phosphatase activities were analyzed and barcoded pyrosequencing of 16S rRNA genes (bacteria) and internal transcribed spacer region (fungi) was conducted. Results: The activity of all the soil enzymes analyzed, along with soil C concentration, declined with soil depth. For example, acid phosphatase activity was 125.9 (± 5.7 (± 1 SE)), 30.9 (± 0.9), 15.7 (± 0.6), 6.7 (± 0.9), and 3.3 (± 0.3) nmol g−1 h−1 at 0–15, 15–30, 30–60, 60–90, and 90–120 cm soil depths, respectively. Among the bacterial groups, the abundance of Proteobacteria (38.5, 23.2, 23.3, 26.1, and 17.5% at 0–15, 15–30, 30–60, 60–90, and 90–120 cm soil depths, respectively) and Firmicutes (12.8, 11.3, 8.6, 4.3, and 0.4% at 0–15, 15–30, 30–60, 60–90, and 90–120 cm soil depths, respectively) decreased with soil depth. On the other hand, the abundance of Ascomycota (51.2, 48.6, 65.7, 46.1, and 45.7% at 15, 30, 60, 90, and 120 cm depths, respectively), a dominant fungal group at this site, showed no clear trend along the soil profile. Conclusions: Our results show that soil C availability can determine soil enzyme activity at different soil depths and that bacterial communities have a clear trend along the soil depth at this study site. These metagenomics studies, along with other studies on microbial functions, are expected to enhance our understanding on the complexity of soil microbial communities and their relationship with biogeochemical factors.