• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.4
• /
• pp.235-244
• /
• 2004

In this study, we compared the levels of methylotrophic bacterial community diversity in the leaf samples of 19 rice cultivars collected from three regions of Korea. Nineteen pink pigmented isolates showing characteristic growth on methanol were obtained. Physiological and biochemical characters of each isolate were examined according to methods described in Bergey's Manual of Systematic Bacteriology. When phylotypes were defined by performing numerical analysis of 37 characteristics, four distinct clusters were formed. The two reference strains, Methylobacterium extorquens AM1 and Methylobacterium fujisawaense KACC10744 were found to group under cluster IV and cluster III respectively. Cluster I diverged on the basis of nitrate reduction and four isolates showed tolerance upto 0.5 M NaCl concentrations. Two strains in cluster I and III were found to possess methane utilizing properties. Most of the isolates in all the four clusters utilized monosaccharides, disaccharide and polyols as carbon source. When the isolates were subjected for indole-3-acetic acid (IAA) analysis in the presence of L-tryptophan, only 8 isolates exhibited IAA production. In addition, the nitrogen source in the medium was found to influence the IAA production. Addition of $(NH_4)_2SO_4$ in the medium led to a 2 to 30 fold increase in the indole synthesis. However, $KNO_3$, $NH_4NO_3$ and $NH_4Cl$ substitution did not significantly stimulate the synthesis of IAA in the growth medium. Result of gnotobiotic root elongation assay significantly increased roots and shoots lengths, and number of lateral roots, which is mediated by IAA production in the culture medium. The rice seedlings primary roots from seeds treated with methylotrophic isolates were on average 27 to 56% longer than the roots from seeds treated with the uninoculated seeds. In addition, application of different high concentrations of authentic IAA ($400g\;mL^{-1}$) to roots of rice seedlings inhibited root growth. However, the IAA concentration from 10 to $200g\;mL^{-1}$, IAA promoted root growth of rice seedlings. These results suggest that bacterial IAA plays a major role in the development of the host plant root system.

• Journal of Plant Biotechnology
• /
• v.4 no.1
• /
• pp.39-44
• /
• 2002

The fast-migrating cationic peroxidase isozyme, named RC3, was purified from rice (Oryza sativa cv. Nak-Dong) callus. Purification of the enzyme was accomplished by ammonium sulfate fractionation, CM-cellulose ionexchange chromatography, and Sephacryl S-100 gel filtration. The molecular mass of the enzyme was about 34 KDa as determined by SDS-PACE and 38 KDa by Sephacryl-100 gel filtration. The pI value of the enzyme was 8.9. Antiserum against RC3 was raised in rabbits, and anti RC3 antiserum reacted with RC3 isozyme by Ouchterlony double immunodiffusion. The optimum pHs and Km values of the enzyme for various substrates were determined. Kinetic studies with various substrates showed that RC3 had very low Km value of 0.01 mM for ferulic acid and ascorbic acid. However, the enzyme did not use esculetin as a substrate.

• Journal of Applied Biological Chemistry
• /
• v.50 no.3
• /
• pp.127-131
• /
• 2007

The properties of two cultivars of japonica rice, Odae (early ripening variety) and Ilpum (late ripening variety), were compared. They grew on MS (Murashige and Skoog) medium but the growth of both cultivars was strongly retarded by 50 mM or more salt. There was no clear difference between the growths of seedlings of the two cultivars for the first 24 h after germination. The amylopectin chain-length profiles of the two cultivars did not differ significantly, and amylopectin content was estimated at $16.0{\pm}0.4%$ in cv. Odae and $16.4{\pm}0.4%$ in cv. Ilpum. A total of 114 RAPD (randomly amplified polymorphic DNA) fragments ranging from 0.4 to 2.5 kb were isolated from the two cultivars, 61 from cv. Odae and 53 from cv. Ilpum, indicating that there is little genetic variation between them.

• Journal of the Korean Society of Industry Convergence
• /
• v.17 no.3
• /
• pp.145-150
• /
• 2014

The purpose of this study was to evaluate the growth of lettuce last for 36 days. Lettuce planted on the same medium with different treatment. The first treatment watering using bio-fertilizer (farmer) and second watering using effective microorganism. Lettuce grown in greenhouse with temperature $18-32^{\circ}C$.Characteristic observed that growth in height and weight of the plants. From the observations that can be generated at high observation, treatment 1 had a higher than treatment 2. On the last day treatment plant with treatment 1 had a 99.8 mm high while treatment 2 has height of 90.7 mm. Observation on severe treatment 1 has a heavier weight than treatment 2. Plants with treatment 1 have a weight on the last day of 0.15665 grams while in plants with treatment 2 weights are 0.11365 grams.

• Molecules and Cells
• /
• v.23 no.2
• /
• pp.207-214
• /
• 2007

lant ${\beta}$-1, 3-glucanases are involved in plant defense and in development. Very little data are available on the expression of rice glucanases both in developmental tissues and under various stresses. In this study, we cloned and characterized twenty-seven rice ${\beta}$-1, 3-glucanases (OsGlu) from at total of 71 putative glucanases. The OsGlu genes were obtained by PCR from a cDNA library and were classified into seven groups (Group I to VII) according to their DNA or amino acid sequence homology. Analysis of the expression of the twenty-seven OsGlu genes by Northern blotting revealed that they were differentially expressed in different developmental tissues as well as in response to plant hormones, biotic stress, high salt etc. OsGlu11 and 27 in Group IV were clearly expressed only in stem and leaf and were also induced strongly by SA (5 mM), ABA ($200{\mu}M$), and M. grisea. OsGlu1, 10, 11, and 14 were induced earlier and to higher levels in incompatible M. grisea interaction than in compatible one. Taken together, our findings suggest that the twenty-seven rice OsGlu gene products play diverse roles not only in plant defense but also in hormonal responses and in development.

• Korean Journal of Environmental Agriculture
• /
• v.26 no.1
• /
• pp.25-35
• /
• 2007

Excess runoff contaminated with N and P can impact the quality of downstream water. It has been known that aquatic plants improve the water quality through their intake of organic or inorganic nutrients. This study was conducted to select aquatic plants having high purification ability for nutrient N and P, and mineral nutrients related to EC such as K, Ca, Na, Cl, and $SO_4$ in raw sewage water in greenhouse. We assessed nutrient phytoremediation potential of alien hydrophyte and hydro-crop as well as native landscape hydrophyte to select suitable aquatic plant applied to artificial wetland and buffering site of stream-side. The amount of irrigation water during whole growing period of aquatic plane ranged from 225 L $m^{-2}$ to 444 L $m^{-2}$. Oryza sativa, Typha orientalis, Zizania latifolia, Aster subulatus, Coix lachryma-jobi var. mayuen, Paspalum disdichum var. indutum which had high biomass consumed the large amount of irrigation water over 350 L $m^{-2}$. As a result of analysis of water purification effect N and P content of shoot biomass, and media soil after experiment, Oryza sativa, Zizania latifolia, Aster subulatus, Coix lachryma-jobi var. mayuen, Paspalum distichum var. indutum showed high purification ability about eutrophication elements such as T-N and T-P. It is presented that Pistia stratiotes, Eichhornia crassipes, and Paspalum distichum var. indutum had excellent purification ability about K, Ca, Na, and Cl. Moreover, Paspalum distichum var. indutum greatly removed $SO_4$ in row sewage water.

• Journal of Plant Biotechnology
• /
• v.44 no.4
• /
• pp.349-355
• /
• 2017

The amino acid composition of rice is a major concern of rice breeders because amino acids are among the most important nutrient components in rice. In this study, a genetic map was constructed with a population of 134 recombinant inbred lines (RILs) from a cross between Dasanbyeo (Tongil-type indica) and TR22183 (temperate japonica), as a means to detect the main and epistatic effect quantitative trait loci (QTLs) for the amino acid content (AAC). Using a linkage map which covered a total of 1458 cM based on 239 molecular marker loci, a total of six main-effect QTLs (M-QTLs) was identified for the content of six amino acids that were mapped onto chromosome 3. For all the M-QTLs, the TR22183 allele increased the trait values. The QTL cluster (flanked by id3015453 and id3016090) on chromosome 3 was associated with the content of five amino acids. The phenotypic variation, explained by the individual QTLs located in this cluster, ranged from 10.2 to 12.4%. In addition, 26 epistatic QTLs (Ep-QTLs) were detected and the 25 loci involved in this interaction were distributed on all nine chromosomes. Both the M-QTLs and Ep-QTLs detected in this study will be useful in breeding programs which target the development of rice with improved amino acid composition.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.4
• /
• pp.271-278
• /
• 2004

This study was conducted to obtain basic information of growth, chlorophyll, and $Na^+\;and\;K^+$ content of rice (Oryza sativa L.) seedlings after transplanting in different NaCl conditions. Plants grown in pots for 8 days after germination were grown for 10 days after transplanting in 50 and 100 mM NaCl concentrations. At higher NaCl concentration, plant height, root length, dry weight and chlorophyll content were reduced with NaCl stress. Among rice cultivars, the shoot dry weight of Gancheokbyeo, Janganbyeo and Hwasungbyeo, and the root dry weight of Janganbyeo, Gancheokbyeo and Juanbyeo showed relatively low reduction compared to the other rice cultivars at 100 mM NaCl stress. The $Na^+$ content in seedling rapidly increased with the increase of NaCl concentration but $K^+$ contents decreased. There was a significant relationship between $Na^+$ content and shoot and root dry weight after transplanting rice seedlings to saline conditions. The shoot and root dry weight showed highly negative relationship with the $Na^+/K^+$ ratio in saline conditions.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.165-165
• /
• 2017

Abiotic stress is one of the major serious limiting factors in rice (Oryza sativa) and caused rice production losses. It is important to precisely screen valuable genetic resources for improving stress tolerance and understanding tolerance mechanism to abiotic stresses. Because there are differences of experiment designs for screening of tolerant plant in several studies related to abiotic stress, this study has performed to provide the rapid and efficiency screening method for selection of tolerance rice to drought and salinity stresses. Two week-old rice seedlings that reached about three leaf stage were treated with drought and salinity stresses and examined tolerant levels with tolerant and susceptible control varieties, and transgenic plants. To determine the optimum concentration for the selection of drought and salinity condition, tolerant, susceptible and wild-type plants were grown under three soil moisture contents (5, 10 and 20% water contents) and three NaCl concentrations (100, 200 and 250 mM) for 10 days at seedling stage. 200 mM NaCl concentration and 5% moisture content soil were determined as the optimum conditions, respectively. The described methodologies in this study are simple and efficiency and might help the selection of drought and salinity tolerance plants at the 3,4-leaf-seedling stage.

• Journal of Plant Biology
• /
• v.36 no.3
• /
• pp.211-218
• /
• 1993

Plant regeneration was accomplished from protoplast culture of rice (Oryza sativa L. cv. Taebaeg). Embryogenic callus was induced from mature seed on MS medium containing 5 mM proline, 2.5 mg/L 2,4-D, 30 g/L sucrose in the dark at 28$^{\circ}C$ and used to establish embryogenic cell suspension culture. Suspension cells were subcultured every one week in N6 medium supplemented with 5 mM proline, 200 mg/L casein hydrolysate, 2.5 mg/L 2,4-D and amino acids of AA medium. Suspension cultures were composed of cells that were densely cytoplasmic, potentially embryogenic and were at least maintained for more than 6 months in liquid medium. Protoplasts were isolated from fast-growing suspension culture cells and cultured in a slightly modified KpR medium by mixed nurse culture. Isolated protoplasts began to divide within 5~7 days and thereafter, protoplast-derived calli were sequentially transferred to callus proliferating medium that soft agar MS medium contained 2 mg/L 2,4-D and produced distinct embryogenic cells. Microcolonies were then transferred to solid medium which consisted of MS medium containing 5 mg/L kinetin, 1 mg/L NAA, 1 mg/L ABA, 30 g/L sucrose and 10 g/L sorbitol under fluorescent light. Mulitple shoots of 4~5 per callus emerged and were transferred to hormone-free MS medium for root initiation. Thereafter, The plantlets were transferred to pots of soil to mature in the culture room.