• The Korean Journal of Ecology
• /
• v.28 no.4
• /
• pp.189-192
• /
• 2005

We tested the field adaptation of Betula schmidtii on the abandoned coal-mine soil with sludge amendment methods for promoting physiological activity of B. schmidtii seedlings under several environmental stress. Sewage sludges were amended to coal-mine soil with B. schmidtii seedlings which grown in the mixture of artificial soil and composted sludge soil before transplanting (before-fertilized treatment, BF) and fertilized with composted sludge after transplanting (after-fertilized treatment, AF). The percent of establishment of seedlings for AF (80.7%) was lower than that for BF (92.7%). Nitrate reductase activity and photosynthetic pigment content were higher in AF than in BF, but malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were lower in AF than in BF These results represent that after-fertilized seedlings increase resistance against physiological stress at field condition using nitrogen source of composted sludge. On the contrary, before-fertilized seedlings were susceptible to environmental stress on abandoned coal-mine soil by exhausting of nitrogen source from composted sludge.

• The Korean Journal of Ecology
• /
• v.15 no.4
• /
• pp.355-363
• /
• 1992

Nitrate reductase activity(NRA) and induced NRA were compared in 4 species of moss ctenidium molluscum, homalothecium, tortella tortusa and neckera crispa collected from limestone in england. the NRA and dry weight of the c. molluscum were also measured after spraying with acidic deposition adjusted to ph 5.6, 4.6, 3.6 and 2.8 with one of two molar ratios of nitric to sulfuric acid, i.e. 1:0(N alone) and 1:2(1N+2S) for 20 days. All 4 species showed high NR leavels in the upper part of cut shoots and occurred maximum inducation of NRA within 6h. c. molluscum had the highest NRA levels among 4 species. after daily spraying of acidic deposition, NRA of c. molluscum was increased much more largely at ph 6 and ph 3.6 derived from N alone than from 1N+2S. However that was decreased at ph 2.8 derived both from N alone and 1N+2S . Decline of dry weight had occurred at ph 3.6 and 2.8 derived both from N alone and 1N+2S. Whereas substantial fertilization effect was observed at ph 4.6 derived from N alone. the data suggest that c. molluscum are able to utilize nitrate more effectivery than any other species, and NRA induction are more sensitive than growth response to nitrogen content of acidicdeposition in a short- term. however toxic effects was detected at high $NO_3$ supply and low phacidic deposition.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.2
• /
• pp.145-149
• /
• 2001

This study was performed to evaluate the growth and nodulation characters of hypernodulating soy-bean mutant, SS2-2, and to know the growth and yield performance of the mutant in infertile soil. Soil fertility was adjusted by mixing the different ratios of soil components including clay, river sand, and horticultural bed, which resulted in fertile and infertile soil. Dry weight, nitrogen concentration, and leaf nitrate reductase of each plant were measured around V6 stage (47 days after planting) and around R3 stage (82 days after planting). There were significant effects of soil fertility and soybean genotype on the total dry weights including root, nodule, stem, leaf, and pod dry weight at V6 and R3 stages. Total dry weight of hypernodulating mutant, SS2-2, was clearly less than that of its wild type, Sinpaldalkong 2. However, nodule development on the roots of SS2-2 was much greater than that of Sinpaldalkong 2, regardless of soil fertility. Though SS2-2 was smaller in plant size than Sinpaldalkong 2, genotypic difference in total nitrogen content was not significant at both V6 and R3 stages because SS2-2 fixed more nitrogen biologically than its wild type in the root nodule. The SS2-2 mutant showed lower plant yield in both infertile and fertile soil. The SS2-2 contained more crude seed protein than Sinpaldalkong 2, and was characterized with reduced top and root growth.

• The Korean Journal of Ecology
• /
• v.23 no.2
• /
• pp.163-167
• /
• 2000

To evaluate the water purification capacity of 4 emergent macrophytes in 4 tributaries of Mankyung River, nitrate reductase activity (NRA) and nutrient removal capacity were determined. Higher NRA occurred in emergent macrophytes such as Persicaria thunbergii and Oenanthe iavanica with 7.8 and 5.4 ${\mu}$moi NO$_2$ g$^{-1}$d.wt. h$^{-1}$. respectively. The nitrogen removal capacity of emergent macrophytes displaying higher NRA fell within the range of 0.85 to 1.95 mg g$^{-1}$d.wt. day$^{-1}$ and was higher in the order Phragmites communis > Persicaria thunbergii > Oenanthe iavanica > Zizania latifolia. The phosphorus removal capacity was within the range of 0.07 to 0.12 mg g$^{-1}$d.wt. day$^{-1}$ and was higher in the order Phragmites communis > Oenanthe iavanica > Persicaria thunbergii > Zizania latifolia. In all the domestic, industrial and agricultural wastewaters, Phragmites communis showed the highest nitrogen and phosphorus removal capacity; 1.36 and 0.0088 mg g$^{-1}$d.wt. day$^{-1}$ respectively. Among the 4 macrophytes. Phragmites communis was the most suitable species for water purification in 4 tributaries of Mankyung River.

• The Plant Pathology Journal
• /
• v.29 no.4
• /
• pp.427-434
• /
• 2013

2R,3R-Butanediol, a volatile compound produced by certain rhizobacteria, is involved in induced drought tolerance in Arabidopsis thaliana through mechanisms involving stomatal closure. In this study, we examined the involvement of nitric oxide and hydrogen peroxide in induced drought tolerance, because these are signaling agents in drought stress responses mediated by abscisic acid (ABA). Fluorescence-based assays showed that systemic nitric oxide and hydrogen peroxide production was induced by 2R,3R-butanediol and correlated with expression of genes encoding nitrate reductase and nitric oxide synthase. Co-treatment of 2R,3R-butanediol with an inhibitor of nitrate reductase or an inhibitor of nitric oxide synthase lowered nitric oxide production and lessened induced drought tolerance. Increases in hydrogen peroxide were negated by co-treatment of 2R,3R-butanediol with inhibitors of NADPH oxidase, or peroxidase. These findings support the volatile 2R,3R-butanediol synthesized by certain rhizobacteria is an active player in induction of drought tolerance through mechanisms involving nitric oxide and hydrogen peroxide production.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.3
• /
• pp.473-476
• /
• 2003

The effect of oxidation-reduction potential (ORP) level on the denitrification by Ochrobactrum anthropi SY509 was investigated under nongrowing condition. The maximum ORP level of nitrate-containing buffer solution was -70∼-80 mV, under which the denitrification took place. By decreasing the initial ORP level, denitrifying enzyme activity was greatly enhanced, which led to higher denitrification efficiency.

• Journal of Plant Biology
• /
• v.29 no.3
• /
• pp.145-156
• /
• 1986

The excretion of ammonia and glutamine synthetase activities were measured in aposymbiotic Paramecium and symbiotic Paramecium. The uptake of nitrate and ammonia, and specific enzyme activities of nitrate reductase, glutamate dehydrogenase and glutamine synthetase were investigated in symbiotic Chlorella from Paramecium bursaria and Chlorella ellipsoidea. The ammonia concentration in the culture media of aposymbiotic Paramecium was increased according to the growth of the Paramecium but it was not changed in symbiotic Paramecium. Nitrate, the major nitrogen source, was taken up at a rate of 0.635 nmol/ 106 Chlorella/hr in Chlorella ellipsoidea. Most of ammonia was assimilated to glutamine by glutamine synthetase, of which acitivty was 1,467 $\mu$mol/mg protein/min in Chlorella elliposidea. Contrary to Chlorella ellipsoidea, ammonia and glutamine transported from the Paramecium were the nitrogen source of symbiotic Chlorella and ammonia was taken up at a rate of 3.854 nmo./106 Chlorella/hr into synmbiotic Chlorella. Most of ammonia were assimilated to glutamate by glutamate dehydrogenase in symbiotic Chlorella. The glutamate dehydrogenase (GDH/NADH) activity was 0.851 $\mu$mol/mg protein/min.

• Environmental Engineering Research
• /
• v.20 no.1
• /
• pp.51-57
• /
• 2015

As expected, the expression of denitrifying genes in a Typha wetland (relatively stagnant compared to other ponds), showing higher nitrogen removal efficiency in summer, was affected by temperature. The abundance and gene transcripts of nitrate reductase (narG), nitrite reductase (nirS), nitric oxide reductase (norB), and nitrous oxide reductase (nosZ) genes in seasonal sediment samples taken from the Acorus and Typha ponds of free surface flow constructed wetlands were investigated using quantitative polymerase chain reaction (Q-PCR) and quantitative reverse transcription PCR (Q-RT-PCR). Denitrifying gene copy numbers ($10^5-10^8$ genes $g^{-1}$ sediment) were found to be higher than transcript numbers-($10^3-10^7$ transcripts $g^{-1}$ sediment) of the Acorus and Typha ponds, in both seasons. Transcript numbers of the four functional genes were significantly higher for Typha sediments, in the warm than in the cold season, potentially indicating greater bacterial activity, during the relatively warm season than the cold season. In contrast, copy numbers and expression of denitrifying genes of Acorus did not provide a strong correlation between the different seasons.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.8
• /
• pp.1254-1261
• /
• 2007

In the present study, we have constructed a bioluminescent bioreporter for the assessment of nitrate/nitrite bioavailability in wastewater. Specifically, an approximately 500-bp DNA fragment containing a nitrate/nitrite-activated nasR-like promoter (regulating expression of genes encoding nitrite reductase in the genus Klebsiella) was fused upstream of the Vibrio fischeri luxCDABE gene cassette in a modified mini-Tn5 vector. Characterization of this strain, designated W6-1, yielded dose-dependent increased bioluminescence coincident with increased nitrate, nitrite, and ammonium added to the growth medium from 1 to 11 ppm. Bioluminescence in response to nitrogen species addition was light dependent up to 10, 7, and 8 ppm with nitrate, nitrite, and ammonium, respectively. This response was linear in the range from 1 to 8 ppm for nitrate ($R^2=0.98$), 1 to 6 ppm for nitrite ($R^2=0.99$), and 1 to 7 ppm for ammonium ($R^2=0.99$). A significant bioluminescent response was also recorded when strain W6-1 was incubated with slurries from aged, nitrate/nitrite contaminated wastewater. Thus, bioreporter strain W6-1 can be used to elucidate factors that constrain the use of nitrate/nitrite in wastewaters.

• Plant Resources
• /
• v.2 no.1
• /
• pp.26-30
• /
• 1999

Nitrate in edible vegetables is converted to nitrite by nitrate reductase(NR) and/or bacteria in intestines. Nitrite and amino, in the intestine of some animals and human, bind to form nitrosamine, which is toxic and known as carcinogen. This study was carried out to examine the effect of added chlorides and their concentrations on growth, yield and nitrate content in leaf lettuce plants in hydroponics. Seeds of lettuce cv, "Samsunjokchukmyon" were planted on April 29, and seedlings were planted on June 2, and were cultured until July 5 in 1998. KCI and CaCl₂ were used as chloride source and their concentrations were 1, 2 and 4 me/L, respectively, in the lettuce standard nutrient solution for National Horticultural Research Institute(NHRI). Completely randomized design with 3 replications was used. Nitrate content and NR activity were measured 2 and 5 weeks after planting(WAP). The obtained results were summarized as the follows : Leaf weight per plant was difference from harvest dates and treatments, but total leaf weight was not significantly different among treatments. Number of leaves was higher in KCI 2 me/L, CaCl₂1 me/L and control at 2 WAP than the others, and was higher in KCI 1 me/L, and control at 3 WAP than others, and was higher in control at 5 WAP. Total number of harvested leaves was the highest in control with 14, which followed by KCI 2 me/L and CaCl₂1 me/L. Nitrate content was decreased by addition of chloride in nutrient solution. Nitrate content in the 3rd and 9th leaves was significantly decreased. NR activity was higher in control and CaCl₂ addition treatments, while KCI addition treatments reduced NR activity. However, no direct relationship with nitrate was observed. Growth characteristics such leaf length and leaf width were not significantly influenced by chloride addition.