• Korean Journal of Soil Science and Fertilizer
• /
• v.16 no.2
• /
• pp.188-194
• /
• 1983

A Pot experiment was conducted to find out the effects of NPK fertilizers and soil amendments on the symbiotic nitrogen fixation and yield of soybean inoculated with Rhizobium japonicum in newly reclaimed upland soil with very low fertility. The results are summarized as follows; 1. Application of PK fertilizer and soil amendments such as lime, and rice straw in combination with micronutrients (Zn, B, Mo) increased the amounts of symbiotic $N_2$ fixation in soybean. 2. The inoculation of Rhizobium japonicum with application of soil amendments increased the yield of soybean by 4% to 10% due to enhanced $N_2$ fixation. 3. In case of improvement of newly reclaimed hilly soil in order to obtain the high yield of soybean, simutaneous application of soil amendments with inoculation of R. janconican should the highest yield.

• Applied Biological Chemistry
• /
• v.40 no.6
• /
• pp.551-555
• /
• 1997

This experiment was carried out to elucidate the biological activity and absorption characteristics of flavonoids in Rhizobium and Bradyrhizobium and to obtain basic information on host specific nodulation by flavonoids in rhizobium-legume symbiosis. The purpose of the present study was to explore the biological activity and the flavonoid absorption indicates that host-specificity is induced by flavonoids in symbiotic nitrogen fixation. Biological activity increased by daidzein and genistein treatment on B. japonicum KCTC 1539 whereas decreased by luteolin treatment but increased by luteolin treatment on R. meliloti whereas decreased by daidzein and genistein treatment. Daidzein and genistein are absorbed by B. japonicum, KCTC 1539 at higher rate than other flavonoids. Especially, luteolin was absorbed at a least rate. Luteolin are absorbed by R. meliloti KCTC 2353 at higher rate than other flavonoids. Especially, daidzein and genistein was absorbed at a least rate.

• Current Research on Agriculture and Life Sciences
• /
• v.12
• /
• pp.69-82
• /
• 1994

This study was conducted to investigate the physiological characteristics and to isolate plasmid DNA of R. japonicum strains. The results obtained were as follows; Strains S117, S118, 005, 011 and DY-1 were slow-growers and showed alkaline reaction, whereas strains S110, S111, S114, S116, S120 and 010 were fast-growers and produced acid reaction in YEM broth. All the fast- and slow-growing R. japonicum showed gram negative and formed mucous white colony on agar plate. After 7 days, the colonies of the fast-growers were between 2.0 and 4.0mm in diameter, whereas those of slow-growers were approximately between 0.5 and 1.5mm. The fast-growers were uniformly sensitive to the pH of 4.5 and tolerant of the pH of 9.5, whereas the reverse was found for the slow-growers. All the fast-growers were able to grow in the presence of 2% NaCl however the slow-growers were not grown. All the microorganisms grew rapidly in simple mineral salt medium containing as the sole source of carbon. Starch was rarely utilized. All the fast-growers utilized sucrose. The slow-growing R. japonicum strains examined usually contained 1 to 3 plasmid DNA ranging between 15Kb and 250 Kb, whereas the fast-growing R. japonicum strains contained 1 to 3 plasmid DNA ranging from 20 Kb to 250Kb.

• Korean Journal of Soil Science and Fertilizer
• /
• v.20 no.3
• /
• pp.275-283
• /
• 1987

In order to find out the effectiveness of nitrogen fixation in rhizobia-legume symbiotic relationship, ecological and physiological characteristics of indigenous rhizobia distributed in Korean soils, that is, dissimilatory nitrate reduction patterns of indigenous soybean rhizobia isolated from four different soils, and differences in one-and two-dimensional polyacrylamide gel electrophoretic pattern of proteins among the each subgroups of Bradyrhizobium japonicum and Rhizobium fredii, were investigated. The results were summarized as follows: 1. The indigenous soybean rhizobia isolated from four different soils could be classified into 4 groups depending on growth rate and dissimilatory nitrate reduction pattern, that is, $S_1$ (slow-grower; Bradyrhizobium japonicum and nitrate denitrifier), $S_2$ (slow-grower; Bradyrhizobium japonicum and nitrate respirer), $F_1$ (fast-grower; Rhizobium fredii and denitrifier), and $F_2$ (fast-grower; Rhizobium fredii and nitrate respirer). 2. The population ratio of fast- to slow-growing R. japonicum was 39% to 61%, and the ratio of denitrifier to nitrate respirer was 31% to 69% and 89% to 11% in fast and slow-grower, respectively. Some differences were observed between fast- and slow-growing R. japonicum but no significant difference was observed between denitrifier and nitrate respirer within same growth type by one and two dimensional SDS-polyacrylamide gel electrophoretic patterns.

• Korean Journal of Microbiology
• /
• v.29 no.1
• /
• pp.40-48
• /
• 1991

Two malonate-specific enzymes, malonyl-CoA synthetase and malonamidase, were found in free-living cultures of Rhizobium japonicum, Rhizobium meliloti, and Rhizobium trifolii, that infect plant roots where contain a high concentration of malonate. Malonyl-CoA synthetase catalyzes the formation of malonyl-CoA, AMP, and PPi directly from malonate, coenzyme A, and ATP in the presence of $Mg^{2+}$ Malonamidase is a novel enzyme that catalyzes hydrolysis and malonyl transfer of malonamate, and forms malonohydroxamate from malonate and hydroxylamine. Both enzymes are highly specific for malonate. These results show that Rhizobia have enzymes able to metabolize malonate and suggest that malonate may be used in symbiotic carbon and nitrogen metabolism.

• Korean Journal of Microbiology
• /
• v.23 no.3
• /
• pp.197-202
• /
• 1985

Different spheroplasting methods using glycine were tried to fast and slow-growing R. japonicum. Although one of the fast growers, R-271 showed normal growth in the presence of 4mg/ml glycine, cell morphology and colony forming unit (CFU) were greatly different from the cells of late log phase grown in the medium without glycine. In parallel, R-271 became sensitive to lysozyme after 6hr incubation in medium containing glycine (3.5mg/ml). After 24hr cultivation in glycine $(100{\mu}g/ml)$ medium, one of the slow growers, R-214 was also susceptible to lysozyme action. Spgeroplasting frequency of both strains was over 96% by glycine and lysozyme. Spheroid cell was also found in bacteroids from root nodule and soluble glycine content was relativiely smaller than other amino acids in soybean nodule extracts.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.2
• /
• pp.141-148
• /
• 1988

Though the cultivation history of soybean in Korea is relatively long, taxonomical study on symbiont nodule bacteria, Rhizobium japonicum is not carried out yet systematically. This work was for the taxonomical study on Korean native R. japonicum by recognizing isolates seroimmunologically as well as for the elucidation of its affinity with host soybean variety. Twenty seven isolates from 13 soybean cultivars cultivated at Seoul National University's experiment field and 6 strains of R. japonicum preserved in our laboratory have been tested. Tube agglutination test, agglutinin adsorption test, and gel immune diffusion test were used. The results obtained are as follows: 1. Twenty five isolates and strains of R. japonicum among 33 were classified into 4 serogroups and identified as indivisual serotype. 2. Two isolates isolated from Hill and Milyang cultivars, 2 isolates from Bangsa and Jangbaek, and 4 isolates from Paldal, Sae-al, and Jangbaek were identified as the same serotype respectively. 3. Seroimmunological tests may be adapted for the elucidation of the affinities between the strains and soybean cultivars as well as strain recognition and systematic classification of Korean native R. japonicum.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.3
• /
• pp.325-331
• /
• 2012

The dual inoculation response of soybean with rhizobium and mycorrhiza was examined in pot vermiculite and field soils. In order to select a symbiotically compatible mycorrhiza with Bradyrhizobium japonicum, a highly germinating spore among 60 strains from 32 upland soils in southern part of Korea was obtained in Acaulospora sp., Gigaspora sp. and Glomus sp., respectively. As a result of dual inoculation of Glycin max cv. Dajangkong and Eunhakong both with $1{\times}10^8$cells of B. japonicum YCK 213 and 10 spores of each mycorrhiza in vermiculite pot, only Glomus sp. treatment together with the rhizobium showed significant increase ($P{\leqq}0.05$) both in shoot dry wt and nodule mass of not Eunhakong but Dajangkong. In red-yellow soils with pH 5.2($1:5H_2O$) and 203 mg of Lancaster P per kg of soil, in which $10^3$ cells of B. japonicum and $10{\pm}0.2$ spores of mycorrhizae per gram of soil were naturalized, grain yield of G. max cv. Dajangkong was increased to 3.9% by dual inoculation both of $4.8{\times}10^6$cells of B. japonicum and 10 spores of mycorrhizae per two seeds under condition applied with 30 kg $P_2O_5$ and 34 kg $K_2O$ per hectare compared to conventionally fertilized plot (2.75 MT $ha^{-1}$) added with 30 kg N $ha^{-1}$. However, there was not significant.

• BMB Reports
• /
• v.35 no.5
• /
• pp.443-451
• /
• 2002

Malonate is a three-carbon dicarboxylic acid. It is well known as a competitive inhibitor of succinate dehydrogenase. It occurs naturally in biological systems, such as legumes and developing rat brains, which indicates that it may play an important role in symbiotic nitrogen metabolism and brain development. Recently, enzymes that are related to malonate metabolism were discovered and characterized. The genes that encode the enzymes were isolated, and the regulation of their expression was also studied. The mutant bacteria, in which the malonate-metabolizing gene was deleted, lost its primary function, symbiosis, between Rhizobium leguminosarium bv trifolii and clover. This suggests that malonate metabolism is essential in symbiotic nitrogen metabolism, at least in clover nodules. In addition to these, the genes matB and matC have been successfully used for generation of the industrial strain of Streptomyces for the production of antibiotics.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.6
• /
• pp.718-724
• /
• 1996

Two soybean cultivars, ‘Lee’ and ‘Peking’, were used to evaluate the competition and interaction of rhizobium strains PRC205 (R. fredii, fast-grower) and USDA110 (B. japonicum, slow-grower). Strains were inoculated separately on the root parts of a split-root growth system. Both root sides were inoculated simultaneously with four combinations of strain treatment to evaluate the competition of strains. And to evaluate the interaction of strains one side of split-root system was inoculated a week prior to the other side. Nodule mass and dry weight of the plants were measured 3 weeks after treatments. PRC205 showed no effective nodulation and no competing ability with USDA110 on Lee cultivar, however, contrary results on Peking cultivar. Top dry weight of Lee inoculated with PRC205 was much lower than that of any other inoculation treatments, however, in Peking that with PRC205 was higher than that with USDA110. There were no differences in root dry weight among the inoculation treatments. USDA110 used as primary inoculant suppressed nodule mass of opposite side, secondary inoculant, severely in both cultivars. PRC205 showed same tendency as USDA110 in Peking, but revealed little suppression effects on USDA110 used as secondary inoculant in Lee. USDA110 used as primary inoculant in Lee and PRC205 in Peking showed much more dry weight of soybean plants than that of other treatments.