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Kim R.J.,Chonnam National University | Kim H.J.,Chonnam National University | Kim H.J.,University of Nebraska - Lincoln | Shim D.,Chonnam National University | And 2 more authors.
Plant Journal | Year: 2016

Monoacylglycerol lipase (MAGL) catalyzes the last step of triacylglycerol breakdown, which is the hydrolysis of monoacylglycerol (MAG) to fatty acid and glycerol. Arabidopsis harbors over 270 genes annotated as 'lipase', the largest class of acyl lipid metabolism genes that have not been characterized experimentally. In this study, computational modeling suggested that 16 Arabidopsis putative MAGLs (AtMAGLs) have a three-dimensional structure that is similar to a human MAGL. Heterologous expression and enzyme assays indicated that 11 of the 16 encoded proteins indeed possess MAG lipase activity. Additionally, AtMAGL4 displayed hydrolase activity with lysophosphatidylcholine and lysophosphatidylethanolamine (LPE) substrates and AtMAGL1 and 2 utilized LPE as a substrate. All recombinant AtMAGLs preferred MAG substrates with unsaturated fatty acids over saturated fatty acids and AtMAGL8 exhibited the highest hydrolase activities with MAG containing 20:1 fatty acids. Except for AtMAGL4, -14 and -16, all AtMAGLs showed similar activity with both sn-1 and sn-2 MAG isomers. Spatial, temporal and stress-induced expression of the 16 AtMAGL genes was analyzed by transcriptome analyses. AtMAGL:eYFP fusion proteins provided initial evidence that AtMAGL1, -3, -6, -7, -8, -11, -13, -14 and -16 are targeted to the endoplasmic reticulum and/or Golgi network, AtMAGL10, -12 and -15 to the cytosol and AtMAGL2, -4 and -5 to the chloroplasts. Furthermore, AtMAGL8 was associated with the surface of oil bodies in germinating seeds and leaves accumulating oil bodies. This study provides the broad characterization of one of the least well-understood groups of Arabidopsis lipid-related enzymes and will be useful for better understanding their roles in planta. © 2016 John Wiley & Sons Ltd.

Lee C.-B.,Korea Green Promotion Agency | Chun J.-H.,National Institute of Forest Science
Forests | Year: 2016

Understanding patterns of biodiversity and their drivers along environmental gradients is one of the central topics in ecology. However, whether diversity patterns along environmental gradients differ among diversity components as well as life forms and what kind of variables control or interact to shape the diversity patterns are poorly known. This study scrutinized the distribution patterns of three plant groups with four diversity indices and evaluated the effects of regional area, topography, topographic heterogeneity, climate, primary productivity, vegetation structure diversity and vegetation type diversity along an extensive elevational gradient on the Baekdudaegan Mountains in South Korea. Different elevational patterns, including hump-shaped, reversed hump-shaped, increasing, multimodal and no relationship, were observed among both the diversity indices and the plant groups. Regional area, habitat heterogeneity and climate were included to explain most of the elevational diversity patterns. In particular, habitat heterogeneity was the most important variable for explaining the patterns of diversity. The results suggest that patterns of elevational diversity may differ not only among plant groups but also among diversity indices and that such patterns are primarily caused by habitat heterogeneity in the Baekdudaegan Mountains because more heterogeneous and diverse habitats can support more coexisting species. © 2016 by the authors.

Lee C.-B.,Korea Green Promotion Agency | Chun J.-H.,National Institute of Forest Science
Folia Geobotanica | Year: 2016

Understanding biodiversity patterns and the underlying drivers along environmental gradients is a central topic in ecology and biogeography. Despite intensive research devoted to the topic, it is poorly known how the diversity components (α-, β- and γ-) are forming the diversity patterns along gradients and whether they differ when taking individual life forms into account. In the present study, we evaluated α-, β- and γ-diversity for all, woody and herbaceous plants in relation to regional area, topographic heterogeneity, vegetation type diversity, climate and primary productivity along an extensive elevation gradient in the temperate forests of South Korea. We also examined the effect of latitude on the diversity patterns. We found differences in patterns among the diversity components as well as life forms. Habitat heterogeneity, represented by topographic heterogeneity and vegetation type diversity, was the most important driver of α- and γ-diversity, and the combined effects of habitat heterogeneity and climate were important for β-diversity of the individual life forms. Diversity patterns did not show significant relationships with latitude. Our results suggest that diversity patterns may differ among diversity components and life forms, and that habitat heterogeneity and climate along an extensive temperate elevation gradient are important biodiversity drivers in South Korea. At the same time, the effect of the elevation gradient may not be paralleled in relation to the latitudinal gradient, and this fact deserves attention in future studies. © 2016 Institute of Botany, Academy of Sciences of the Czech Republic

Kwon T.-S.,National Institute of Forest Science
Journal of Asia-Pacific Biodiversity | Year: 2016

Ant assemblages in the soil have been studied at eight forest sites (4 oak forest sites, and 4 pine forest sites) in four study areas (1 seminatural area, and 3 industrialized areas) in South Korea for 6 years from 2002 to 2010. Soil cores and Tullgren funnel were used for the ant survey. Ant surveys were carried out once per year in autumn (from late September to mid-October). The soil pH was lower in the industrialized than in the seminatural area, showing the acidified soils in the industrialized areas. However, the soil acidification did not influence the ant assemblages. The results from the nonmetric multidimensional scaling ordination and from the community temperature index values indicate that temperature is a key determinant for structures of the soil ant assemblages. The ant assemblages were not different according to the forest types (oak forests vs. pine forests). Occurrence of ant species varied greatly among years, indicating that more replicates and advanced sampling method are needed for the monitoring of the soil ant assemblages. Copyright © 2016, National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA). Production and hosting by Elsevier. This is an open access article under the CC BY-NC-ND license.

Jeong M.-A.,National Institute of Forest Science | Jeong M.-A.,Seoul National University | Park S.,National Institute of Forest Science | Park S.,Seoul National University | Song G.-S.,Korea University
Urban Forestry and Urban Greening | Year: 2016

This study elucidated the thermal effects of urban forests on physiological and psychological responses; changes in skin temperature, thermal sensation, and thermal preferences. The air temperature, relative humidity, air velocity, and globe temperature were measured in an urban forest and a central building district (CBD) area. Changes in skin temperature were analyzed for 12 subjects in both areas. A total of 790 individuals were interviewed on the actual thermal comfort. The results showed that air temperature and outdoor standard effective temperature (OUT_SET*) in the summer and autumn were higher at the CBD than at the urban forest area (p < 0.01). In summer, the mean skin temperature was 35.0 °C at the CBD and 34.0 °C at the urban forest area, respectively. In autumn, it was 33.3 °C and 31.3 °C. During the summer, 60.3% of participants felt hot sensation in the CBD (23.8%, in the forest), while 79.3% felt comfortable in the urban forest (31.1%, in the CBD). The comfortable air temperature range in the urban forest area was 12.1 to 21.6 °C, it was broader than in the CBD. People in the urban forest area felt more comfortable than did those in the CBD. These findings suggest that urban forests increase thermal comfort and widen the comfortable temperature range. © 2015 Elsevier GmbH.

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