MuSI, a gene that corresponds to a domain that contains the rubber elongation factor (REF), is hi... more MuSI, a gene that corresponds to a domain that contains the rubber elongation factor (REF), is highly homologous to many stress-related proteins in plants. Since MuSI is up-regulated in the roots of plants treated with cadmium or copper, the involvement of MuSI in cadmium tolerance was investigated in this study. Escherichia coli cells overexpressing MuSI were more resistant to Cd than wild-type cells transfected with vector alone. MuSI transgenic plants were also more resistant to Cd. MuSI transgenic tobacco plants absorbed less Cd than wild-type plants. Cd translocation from roots to shoots was reduced in the transgenic plants, thereby avoiding Cd toxicity. The number of short trichomes in the leaves of wild-type tobacco plants was increased by Cd treatment, while this was unchanged in MuSI transgenic tobacco. These results suggest that MuSI transgenic tobacco plants have enhanced tolerance to Cd via reduced Cd uptake and/or increased Cd immobilization in the roots, resulting in l...
This study was carried out to find out potential use of ochre as an agent to reduce phosphorus co... more This study was carried out to find out potential use of ochre as an agent to reduce phosphorus content in water. Ochre is a by-product from treatment of acid mine drainage (AMD) which is composed mostly of , , and . Three ochre samples (ochre-H, ochre-D and ochre-S) were collected from three treatment facilities in Gangwon province. Physico-chemical characteristics of three ochre samples including pH, electrical conductivity, total phosphorus, available phosphorus, particle size distribution were analyzed. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis were also carried out. In addition, experiments for phosphorus removal from water was performed. Calcium content of ochre-H was higher than that of ochre-D and ochre-S, whereas iron content of ochre-H was lower than that of ochre-D and ochre-S. All the phosphorus in water up to maximum 191,411 mg per unit mass of ochre was removed with ochre-H. Och...
The current study was performed to examine the agricultural suitability of the cultivated upland ... more The current study was performed to examine the agricultural suitability of the cultivated upland nearby abandoned mining areas in Korea using three different scientific risk assessment models of Korea, USA and UK. For this, three mining sites DM, MG and KS were selected among 687 abandoned mines through preliminary risk assessment. A wide range of parameters were obtained through analysis of both soil and crop samples from the selected areas for heavy metal concentration and questionnaires to the communities along with the selected mining sites. Heavy metal concentration in soil samples was lower than the values previously reported by the Ministry of Environment (ME, 2002). However, both As and Cd concentration in the soil samples exceeded the concern level for agricultural area of the Soil Environment Conservation Act. Judging from the contaminant criteria for the crops, only Zn level in pepper, soybean and corn from the mining area DM exceeded the criteria whereas As, Cd, , Cu, Hg...
This study was carried out to identify the potential for phytoremediation of soils contaminated w... more This study was carried out to identify the potential for phytoremediation of soils contaminated with Cd using MuS1 (line 6) transgenic tobacco. The experiment was composed of two parts: i) Effect of cadmium treatment on germination rate; and ii) Effect of cadmium treatment on growth with hydroponic system. MuS1 tobacco seeds geminated and grew better than wild-type tobacco seeds. The tolerance of MuS1 transgenic tobacco to Cd stress was better than that of wild-type tobacco at all Cd treatment levels. Especially, wild-type tobacco showed chlorosis and withering with 200µM Cd treatment, but MuS1 tobacco gradually recovered from Cd damage. Results of this study showed potential for phytoremediation of soils contaminated with Cd using MuS1 transgenic tobacco. They also indicated potential for biofuel production from the area where soils are contaminated with Cd using MuS1 transgenic tobacco. Introduction Soil contamination by human being goes back as far as the Bronze Age (2500 B.C.) (...
Urban soils are prone to contamination by trace elements such as Cd, Cu, Pb and Zn. Phytoremediat... more Urban soils are prone to contamination by trace elements such as Cd, Cu, Pb and Zn. Phytoremediation is one of the attractive remediation methods for soils contaminated with trace elements due to its non-destructive and environmentally-friendly characteristic. Scientists have tried to find hyper-accumulator plants in nature or to develop transgenic plant through genetic engineering. This study was carried out to identify a potential of MuS1 transgenic tobacco for phytoremediation of the urban soils contaminated with Cd. MuS1 is known as a multiple stress related gene with several lines. The previous study using RT-PCR showed that the expression of MuS1 gene in tobacco plant induced tolerance to Cd stress. For this study, MuS1 transgenic tobacco and wild-type tobacco (control) were cultivated in a hydroponic system treated with Cd (0, 50, 100 and 200muM Cd) for 3 weeks. At harvest, both tobacco and nutrient solution were collected and were analyzed for Cd. Effect of Cd treatment on m...
Plastic is an indispensable material essential for modern human life. With highly increasing de- ... more Plastic is an indispensable material essential for modern human life. With highly increasing de- mand for plastic use, however, environmental contamination by plastic litters has become an emerging issue. Globally, large quantity of used plastics is landfilled or emitted directly to the aquatic and terrestrial environments, albeit a part of the plastics is recycled or incinerated as energy source. In particular, microplastic debris that are smaller than 5 mm are considered to be emerging contaminants of global concern. In the past decade, however, most of the researches on impacts of microplastic contamination have been focused on the marine ecosystem, whereas very limited ones on the terrestrial ecosystem. Soil can be considered as a major sink and a car- rier of microplastic contaminants to the aquatic environment. Most sources of microplastics in the soil environment are entered via a variety of routes and subsequent fragmented and spread to the surrounding environments, vertically and horizontally. In addition, there are negative im- pacts on soil biota, which in turn would cause concerns of human health by affecting the food web. Here, we provide an overview of characteristics, research trend, analytical methods, migra- tion and degradation processes, effects on soil biogeochemistry, and interaction with soil organ- isms of microplastics suggesting the importance of ongoing research impacts of microplastics on the terrestrial ecosystem.
Laboratory incubation studies were used to investigate whether and how variability of different p... more Laboratory incubation studies were used to investigate whether and how variability of different plant litters modifies the mobility of nitrogen in soil. Fallen plant foliage from native New Zealand plants of diverse fibre and nutrient content were selected, with C : N ratios ranging from 14 to 102. Different litters provided substantially different inputs of macro-and micronutrients to soil that affected the mobility of N. Both fibre content and C : N ratios were influential. A primary effect of litter addition to soil was modification of pH, largely attributable to calcium enrichment. Nitrate in soil was reduced by up to 85% following litter amendments. Incorporation of five native plant litters into soil significantly suppressed emissions of nitrous oxide. We interpret these findings in the context of plant residues from naturalistic planting on the borders of farm paddocks that may play a role in tightening the N cycle and restricting spillover of nitrogen pollutants to the wider environment.
Soil phosphorus (P) is a critical nutrient for plant growth and is an important determinant of ve... more Soil phosphorus (P) is a critical nutrient for plant growth and is an important determinant of vegetation development and long-term ecosystem sustainability. We investigated the effects of rhizosphere-earthworm-guano interactions on soil P dynamics in a mesocosm involving two species of native New Zealand earthworms (Megascolecidae Sp.1 and Maoridrilus transalpinus) and introduced Eisenia fetida, in the context of inputs from seabird guano and the ecological restoration of a unique coastal sandplain forest. A fully factorial experimental design included a tall fibrous liliaceous perennial plant (New Zealand flax) growing in a low P forest soil, a guano-P amendment (with and without guano-P), and earthworm inoculation (with and without species of epigeics, endogeics and anecics). Soil dehydrogenase activity, CaCl 2-P, citrate-P and HCl-P were significantly modified by earthworm-guano interactions, altering the P status of the original forest soil. Furthermore, interactions between the rhizosphere and earthworms stimulated transformation of soil P and guano P; the proportional importance of soil microbial biomass P, organic-P and more soluble P fractions were substantially modified. These findings show that rhizosphere-earthworm interactions are likely to mediate the supply, chemical forms and plant-availability of P, and are likely to have an important role in successional processes and the trajectory of ecological restoration in coastal forests of New Zealand.
Among many disposal options of animal carcasses due to animal diseases including foot-and-mouth d... more Among many disposal options of animal carcasses due to animal diseases including foot-and-mouth disease (FMD) and avian influenza (AI), on-farm burial has been the most frequently used one in Korea. Animal carcasses generate contaminants such as ammonium-N and chloride. This study aimed at testing biochar (BC) as a permeable reactive barrier (PRB) material in combination with fast growing tree species (Populus euramericana) to mitigate groundwater pollution from animal burial sites. For this, a PRB filled with BC was installed and 400 poplar tree (P. euramericana) seedlings were planted. Tested BC was obtained from rice husk and its efficiency to mitigate contaminant migration from a burial site of pig carcasses was tested using ammonium-N, chloride, electrical conductivity (EC), and pH as monitoring parameters. Monitoring wells downstream from the burial site were used. Leachates from a monitoring well, three wells inside the burial site close to PRB and three wells outside the burial site close to PRB were sampled and analyzed for ammonium-N, Cl − , EC, and pH for four years from PRB installation. The pH, EC, and ammonium-N of leachate fluctuated during the test period depending on precipitation. pH, EC, and ammonium-N of the leachate samples collected from outside of the burial site close to PRB decreased compared to those from inside of the burial site close to PRB. The concentrations of ammonium-N in the leachate from the monitoring well kept under the threshold value of 10 mg·L −1 for two years from PRB construction. In addition, the growth of poplar plants appeared to be increased via uptaking available N and P released from the burial sites. Achieved results suggest that BC PRBs can be used to in situ mitigate contaminant release from buried animal carcasses.
Important knowledge gaps remain with regards to the ecology and the systematics of New Zealand’s ... more Important knowledge gaps remain with regards to the ecology and the systematics of New Zealand’s native earthworms. With many putative new species yet to be described, often specimens cannot be named, which makes species inventory, monitoring and community comparisons dif cult. Our work aimed to identify new putative taxa of New Zealand native species of earthworms, and describe their distribution in selected human-modi ed ecosystems. A total of 24 earthworm taxa (13 native and 11 exotic) were identi ed using a DNA barcoding approach focusing on 16S rDNA and COI (cytochrome oxidase subunit 1). The combination of morphological and molecular analyses were complementary in elucidating species identity. However, of the 13 native taxa, eight could not be named and are likely to be undescribed species from the genera Octochaetus, Maoridrilus and Deinodrilus. Most native species appeared to have a restricted geographic distribution linked to soil conditions, in particular pH and organic matter.
Attempts to restore native biodiversity into agricultural landscapes in New Zealand appear to be ... more Attempts to restore native biodiversity into agricultural landscapes in New Zealand appear to be compromised both by soil nitrogen enrichment from farming and N-leakage to the wider environment. We investigated whether interactions between native earthworms and a native rhizobium-inoculated leguminous shrub (Sophora microphylla) have a measurable effect on the mobility of nitrogen in an agricultural soil that has been nitrogen-enriched and colonised by exotic earthworms. Plants grew better in the presence of both native and exotic soil-burrowing earthworms. Rates of root nodulation were considerably enhanced in the presence of the native megascolecid anecic earthworm Maoridrilus transalpinus. This species consumed more organic matter in the presence of inoculated plants whilst marginally lowering soil pH and enhancing critical concentrations of nitrate, but also reducing nitrous oxide emissions. Earthworms raised dehydrogenase enzyme activity and microbial activity in soil, but this was not commensurate with rates of nodulation. Our results show that some combination of earthworm-mediated soil aeration, modification of moisture conditions in the rhizosphere and drilosphere, and comminution of organic matter, modify microbial communities and significantly impact the N cycle.
MuSI, a gene that corresponds to a domain that contains the rubber elongation factor (REF), is hi... more MuSI, a gene that corresponds to a domain that contains the rubber elongation factor (REF), is highly homologous to many stress-related proteins in plants. Since MuSI is up-regulated in the roots of plants treated with cadmium or copper, the involvement of MuSI in cadmium tolerance was investigated in this study. Escherichia coli cells overexpressing MuSI were more resistant to Cd than wild-type cells transfected with vector alone. MuSI transgenic plants were also more resistant to Cd. MuSI transgenic tobacco plants absorbed less Cd than wild-type plants. Cd translocation from roots to shoots was reduced in the transgenic plants, thereby avoiding Cd toxicity. The number of short trichomes in the leaves of wild-type tobacco plants was increased by Cd treatment, while this was unchanged in MuSI transgenic tobacco. These results suggest that MuSI transgenic tobacco plants have enhanced tolerance to Cd via reduced Cd uptake and/or increased Cd immobilization in the roots, resulting in l...
This study was carried out to find out potential use of ochre as an agent to reduce phosphorus co... more This study was carried out to find out potential use of ochre as an agent to reduce phosphorus content in water. Ochre is a by-product from treatment of acid mine drainage (AMD) which is composed mostly of , , and . Three ochre samples (ochre-H, ochre-D and ochre-S) were collected from three treatment facilities in Gangwon province. Physico-chemical characteristics of three ochre samples including pH, electrical conductivity, total phosphorus, available phosphorus, particle size distribution were analyzed. Scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis were also carried out. In addition, experiments for phosphorus removal from water was performed. Calcium content of ochre-H was higher than that of ochre-D and ochre-S, whereas iron content of ochre-H was lower than that of ochre-D and ochre-S. All the phosphorus in water up to maximum 191,411 mg per unit mass of ochre was removed with ochre-H. Och...
The current study was performed to examine the agricultural suitability of the cultivated upland ... more The current study was performed to examine the agricultural suitability of the cultivated upland nearby abandoned mining areas in Korea using three different scientific risk assessment models of Korea, USA and UK. For this, three mining sites DM, MG and KS were selected among 687 abandoned mines through preliminary risk assessment. A wide range of parameters were obtained through analysis of both soil and crop samples from the selected areas for heavy metal concentration and questionnaires to the communities along with the selected mining sites. Heavy metal concentration in soil samples was lower than the values previously reported by the Ministry of Environment (ME, 2002). However, both As and Cd concentration in the soil samples exceeded the concern level for agricultural area of the Soil Environment Conservation Act. Judging from the contaminant criteria for the crops, only Zn level in pepper, soybean and corn from the mining area DM exceeded the criteria whereas As, Cd, , Cu, Hg...
This study was carried out to identify the potential for phytoremediation of soils contaminated w... more This study was carried out to identify the potential for phytoremediation of soils contaminated with Cd using MuS1 (line 6) transgenic tobacco. The experiment was composed of two parts: i) Effect of cadmium treatment on germination rate; and ii) Effect of cadmium treatment on growth with hydroponic system. MuS1 tobacco seeds geminated and grew better than wild-type tobacco seeds. The tolerance of MuS1 transgenic tobacco to Cd stress was better than that of wild-type tobacco at all Cd treatment levels. Especially, wild-type tobacco showed chlorosis and withering with 200µM Cd treatment, but MuS1 tobacco gradually recovered from Cd damage. Results of this study showed potential for phytoremediation of soils contaminated with Cd using MuS1 transgenic tobacco. They also indicated potential for biofuel production from the area where soils are contaminated with Cd using MuS1 transgenic tobacco. Introduction Soil contamination by human being goes back as far as the Bronze Age (2500 B.C.) (...
Urban soils are prone to contamination by trace elements such as Cd, Cu, Pb and Zn. Phytoremediat... more Urban soils are prone to contamination by trace elements such as Cd, Cu, Pb and Zn. Phytoremediation is one of the attractive remediation methods for soils contaminated with trace elements due to its non-destructive and environmentally-friendly characteristic. Scientists have tried to find hyper-accumulator plants in nature or to develop transgenic plant through genetic engineering. This study was carried out to identify a potential of MuS1 transgenic tobacco for phytoremediation of the urban soils contaminated with Cd. MuS1 is known as a multiple stress related gene with several lines. The previous study using RT-PCR showed that the expression of MuS1 gene in tobacco plant induced tolerance to Cd stress. For this study, MuS1 transgenic tobacco and wild-type tobacco (control) were cultivated in a hydroponic system treated with Cd (0, 50, 100 and 200muM Cd) for 3 weeks. At harvest, both tobacco and nutrient solution were collected and were analyzed for Cd. Effect of Cd treatment on m...
Plastic is an indispensable material essential for modern human life. With highly increasing de- ... more Plastic is an indispensable material essential for modern human life. With highly increasing de- mand for plastic use, however, environmental contamination by plastic litters has become an emerging issue. Globally, large quantity of used plastics is landfilled or emitted directly to the aquatic and terrestrial environments, albeit a part of the plastics is recycled or incinerated as energy source. In particular, microplastic debris that are smaller than 5 mm are considered to be emerging contaminants of global concern. In the past decade, however, most of the researches on impacts of microplastic contamination have been focused on the marine ecosystem, whereas very limited ones on the terrestrial ecosystem. Soil can be considered as a major sink and a car- rier of microplastic contaminants to the aquatic environment. Most sources of microplastics in the soil environment are entered via a variety of routes and subsequent fragmented and spread to the surrounding environments, vertically and horizontally. In addition, there are negative im- pacts on soil biota, which in turn would cause concerns of human health by affecting the food web. Here, we provide an overview of characteristics, research trend, analytical methods, migra- tion and degradation processes, effects on soil biogeochemistry, and interaction with soil organ- isms of microplastics suggesting the importance of ongoing research impacts of microplastics on the terrestrial ecosystem.
Laboratory incubation studies were used to investigate whether and how variability of different p... more Laboratory incubation studies were used to investigate whether and how variability of different plant litters modifies the mobility of nitrogen in soil. Fallen plant foliage from native New Zealand plants of diverse fibre and nutrient content were selected, with C : N ratios ranging from 14 to 102. Different litters provided substantially different inputs of macro-and micronutrients to soil that affected the mobility of N. Both fibre content and C : N ratios were influential. A primary effect of litter addition to soil was modification of pH, largely attributable to calcium enrichment. Nitrate in soil was reduced by up to 85% following litter amendments. Incorporation of five native plant litters into soil significantly suppressed emissions of nitrous oxide. We interpret these findings in the context of plant residues from naturalistic planting on the borders of farm paddocks that may play a role in tightening the N cycle and restricting spillover of nitrogen pollutants to the wider environment.
Soil phosphorus (P) is a critical nutrient for plant growth and is an important determinant of ve... more Soil phosphorus (P) is a critical nutrient for plant growth and is an important determinant of vegetation development and long-term ecosystem sustainability. We investigated the effects of rhizosphere-earthworm-guano interactions on soil P dynamics in a mesocosm involving two species of native New Zealand earthworms (Megascolecidae Sp.1 and Maoridrilus transalpinus) and introduced Eisenia fetida, in the context of inputs from seabird guano and the ecological restoration of a unique coastal sandplain forest. A fully factorial experimental design included a tall fibrous liliaceous perennial plant (New Zealand flax) growing in a low P forest soil, a guano-P amendment (with and without guano-P), and earthworm inoculation (with and without species of epigeics, endogeics and anecics). Soil dehydrogenase activity, CaCl 2-P, citrate-P and HCl-P were significantly modified by earthworm-guano interactions, altering the P status of the original forest soil. Furthermore, interactions between the rhizosphere and earthworms stimulated transformation of soil P and guano P; the proportional importance of soil microbial biomass P, organic-P and more soluble P fractions were substantially modified. These findings show that rhizosphere-earthworm interactions are likely to mediate the supply, chemical forms and plant-availability of P, and are likely to have an important role in successional processes and the trajectory of ecological restoration in coastal forests of New Zealand.
Among many disposal options of animal carcasses due to animal diseases including foot-and-mouth d... more Among many disposal options of animal carcasses due to animal diseases including foot-and-mouth disease (FMD) and avian influenza (AI), on-farm burial has been the most frequently used one in Korea. Animal carcasses generate contaminants such as ammonium-N and chloride. This study aimed at testing biochar (BC) as a permeable reactive barrier (PRB) material in combination with fast growing tree species (Populus euramericana) to mitigate groundwater pollution from animal burial sites. For this, a PRB filled with BC was installed and 400 poplar tree (P. euramericana) seedlings were planted. Tested BC was obtained from rice husk and its efficiency to mitigate contaminant migration from a burial site of pig carcasses was tested using ammonium-N, chloride, electrical conductivity (EC), and pH as monitoring parameters. Monitoring wells downstream from the burial site were used. Leachates from a monitoring well, three wells inside the burial site close to PRB and three wells outside the burial site close to PRB were sampled and analyzed for ammonium-N, Cl − , EC, and pH for four years from PRB installation. The pH, EC, and ammonium-N of leachate fluctuated during the test period depending on precipitation. pH, EC, and ammonium-N of the leachate samples collected from outside of the burial site close to PRB decreased compared to those from inside of the burial site close to PRB. The concentrations of ammonium-N in the leachate from the monitoring well kept under the threshold value of 10 mg·L −1 for two years from PRB construction. In addition, the growth of poplar plants appeared to be increased via uptaking available N and P released from the burial sites. Achieved results suggest that BC PRBs can be used to in situ mitigate contaminant release from buried animal carcasses.
Important knowledge gaps remain with regards to the ecology and the systematics of New Zealand’s ... more Important knowledge gaps remain with regards to the ecology and the systematics of New Zealand’s native earthworms. With many putative new species yet to be described, often specimens cannot be named, which makes species inventory, monitoring and community comparisons dif cult. Our work aimed to identify new putative taxa of New Zealand native species of earthworms, and describe their distribution in selected human-modi ed ecosystems. A total of 24 earthworm taxa (13 native and 11 exotic) were identi ed using a DNA barcoding approach focusing on 16S rDNA and COI (cytochrome oxidase subunit 1). The combination of morphological and molecular analyses were complementary in elucidating species identity. However, of the 13 native taxa, eight could not be named and are likely to be undescribed species from the genera Octochaetus, Maoridrilus and Deinodrilus. Most native species appeared to have a restricted geographic distribution linked to soil conditions, in particular pH and organic matter.
Attempts to restore native biodiversity into agricultural landscapes in New Zealand appear to be ... more Attempts to restore native biodiversity into agricultural landscapes in New Zealand appear to be compromised both by soil nitrogen enrichment from farming and N-leakage to the wider environment. We investigated whether interactions between native earthworms and a native rhizobium-inoculated leguminous shrub (Sophora microphylla) have a measurable effect on the mobility of nitrogen in an agricultural soil that has been nitrogen-enriched and colonised by exotic earthworms. Plants grew better in the presence of both native and exotic soil-burrowing earthworms. Rates of root nodulation were considerably enhanced in the presence of the native megascolecid anecic earthworm Maoridrilus transalpinus. This species consumed more organic matter in the presence of inoculated plants whilst marginally lowering soil pH and enhancing critical concentrations of nitrate, but also reducing nitrous oxide emissions. Earthworms raised dehydrogenase enzyme activity and microbial activity in soil, but this was not commensurate with rates of nodulation. Our results show that some combination of earthworm-mediated soil aeration, modification of moisture conditions in the rhizosphere and drilosphere, and comminution of organic matter, modify microbial communities and significantly impact the N cycle.
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Papers by Young-nam Kim