• 미생물학회지
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• 제29권2호
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• pp.143-147
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• 1991

The root nodules and Glycine max were classified as determinate nodule based on their morphological characteristics, and isolated endosymbiont as a Bradyrhizobium based on its growth rate and single subpolar flagellum. The isolate was similar to B. japonicum USDA110 in utilization of carbon source, growth at 38.deg.C and 2% NaCl, production of $H_{2}$S and especially in the restriction endonuclease digestion pattern of symbiotic genes, allowing them to be placed in sTI group together. The former, however, grew better than the later in broad pH range from 5.0 to 9.5. Infectivity and effectivity of the isolate were confirmed by inoculation of soybean seedlings with the isolates. Characteristics of the reisolated endosymbiont from induced root nodules were identical to those of the first isolate. From these results, it was confirmed that Bradyrhizobium strain isolated from the root nodules of Glycine max was a real symbiont, and was named B. japonicum SNU001.

• Molecules and Cells
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• 제23권3호
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• pp.405-409
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• 2007

A putative type-I chalcone isomerase (CHI) cDNA clone EuNOD-CHI was previously isolated from the root nodule of Elaeagnus umbellata [Kim et al. (2003)]. To see if it encodes a functional CHI, we ectopically overexpressed it in the Arabidopsis (Arabidopsis thaliana) transparent testa 5 (tt5) mutant, which is defective in naringenin production and has yellow seeds due to proanthocyanidin deficiency. Ectopic overexpression of EuNOD-CHI resulted in recovery of normal seed coat color. Naringenin produced by CHI from naringenin chalcone was detected in the transgenic lines like in the wild-type, whereas it was absent from the tt5 mutant. We conclude that EuNOD-CHI encodes a functional type-I CHI. In situ hybridization revealed that EuNOD-CHI expression is localized to the infected cells of the fixation zone in root nodules.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 춘계학술발표대회:발표논문요지록
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• pp.14-14
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• 1999

• 한국작물학회지
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• 제46권2호
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• pp.145-149
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• 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.

• Journal of Plant Biology
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• 제29권2호
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• pp.109-115
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• 1986

Actinorhizal plants being capable of fixing atmospheric nitrogen in symbiotic association with Frankia were surveyed for their root nodules, and the root nodules were collected for further studies. Three species of Alnus and Elaeagnus (A. hirsuta, a. firma, A. japonica; E. glabra, e. umbellata, E. macrophylla) and one species of Myrica (M. rubura) were confirmed to bear the root nodules of typical external shape. Morphological studies using light microscope and scanning electron microscope revealed the presence of vesicle clusters in the cortex region of the root. Two tentative endophyte colonies were isolated from the root nodule of A. hirsuta.

• The Korean Journal of Ecology
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• 제22권3호
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• pp.131-137
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• 1999

금호강(영천, 침산교, 팔달교, 달서천, 금호교)에서 널리 군락을 이루고 있는 갈퀴나물의 무기물 및 중금속 함량과 질소고정 활성의 변화양상을 비교 분석하였다. 금호강변 토양은 하류로 갈수록 무기물과 중금속 함량이 증가되었고, 더불어 식물체에도 높은 축적량을 보였다. 갈퀴나물은 비오염지에 비해 오염지역에서 지하부에 비해 지상부가 크게 발달되어 높은 T/R비를 보이면서 군락을 형성하였다. 식물체의 함수량은 생육후기 지상부에서 다소 높게 나타났고, 단위 g당 엽록소함량이 비교적 높게 나타났다. 근류는 4월에 형성되어 6월에 비오염지의 0.3 g/plant에 비해 침산교, 팔달교, 달서천 및 금호교에서 각각 0.27, 0.24, 0.06 및 0.14 g/plant로 최대치를 보였고, 비오염지 영천에서 23.1 μmol. C₂H₄·g fw nodule/sup -1/·h/sup -1/을 보인 근류의 질소고정 활성도 각각 16.8, 15.4, 8.5 및 5.3 μmol. C₂H₄·g fw nodule/sup -1/·h/sup -1/로, 하류지역으로 갈수록 감소된 활성을 보였고, 달서천과 금호교에서 심각한 저해를 보였다. 갈퀴나물은 흡수한 중금속 (Zn, Cu, Fe, Pb 등)을 지하부에서 높은 함량을 유지하였고, 질소함량은 생육후기로 갈수록 초기에 비해 지상부는 감소되었으나 지하부에서 높은 값을 보였다. 한편, 식물체내 총중금속량은 높은 T/R비로 인해 지상부에서 높은 값을 보였다. 흡수한 Ca는 대부분 지상부로 이동시켜 지하부에서 높은 함량을 보인 금속류와는 대조를 이루었다. 결과적으로, 갈퀴나물은 지상부에 높은 Ca함량을 나타내고, 지하부에 높은 중금속함량과 함께 질소의 함량도 높게 유지하면서 오염된 지역에서 생장 적응하는 것으로 판단된다.

• Molecules and Cells
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• 제23권1호
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• pp.115-121
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• 2007

Root nodule formation is controlled by plant hormones such as auxin. Auxin-repressed protein (ARP) genes have been identified in various plant species but their functions are not clear. We have isolated a full-length cDNA clone (EuNOD-ARP1) showing high sequence homology to previously identified ARP genes from root nodules of Elaeagnus umbellata. Genomic Southern hybridization showed that there are at least four ARP-related genes in the genome of E. umbellata. The cDNA clone encodes a polypeptide of 120 amino acid residues with no signal peptide or organelle-targeting signals, indicating that it is a cytosolic protein. Its cytosolic location was confirmed using Arabidopsis protoplasts expressing a EuNOD-ARP1:smGFP fusion protein. Northern hybridization showed that EuNOD-ARP1 expression was higher in root nodules than in leaves or uninoculated roots. Unlike the ARP genes of strawberry and black locust, which are negatively regulated by exogenous auxin, EuNOD-ARP1 expression is induced by auxin in leaf tissue of E. umbellata. In situ hybridization revealed that EuNOD-ARP1 is mainly expressed in the fixation zone of root nodules.

• 한국작물학회지
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• 제50권2호
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• pp.125-130
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• 2005

In the absence of exogeneous nitrogen supply, evaluation of a symbiosis effectiveness of Bradyrhizobium japonicum USDA 110 in a supernodulating soybean mutant, SS2-2, its wild type, Sinpaldalkong 2, and control genotype, Jangyeobkong, was conducted in this study. Nodules in SS2-2 were initially white and similar to its wild type, Sinpaldalkong 2. At the late stage, the wild type nodules became dark pinkish by maturation, by contrast, mature nodules in SS2-2 remained light green to pinkish, indicating a lack of leghemoglobin. Tap root length was short in nodulated symbiotic SS2-2 than that of its wild type and the control genotype. Nodulated root length and nodule density on root length were significantly increased by B. japonicum inoculation, but no significant increase was observed on root length and percentage of nodulation to total root length. Regardless of Bradyrhizobium inoculation, SS2-2 showed higher nodule dry weight and higher acetylene reduction activity (ARA) when compared with its wild type and the control genotype. Inoculation of B. japonicum leaded the increase of ARA in 47 days after planting (DAP), in part because of nodule development. Supernodulating mutant, SS2-2, less responded to B. japonicum induction in terms of nitrogen fixation and nodulation characteristics than its wild type. Thus, interaction of supernodulating soybean mutant with Bradyrhizobium had less symbiotically associated response than normal nodulating soybean.

• 한국초지조사료학회지
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• 제14권3호
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• pp.177-185
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• 1994

Slow seedling growth rate and nodulation failure of white clover (Trifolium repens L.) has been limited its good establishment to pastures. The experiment was done to determine the effect of removal of cotyledon and unifoliolate on the shoot, root growth, and nodule formation of 4 white clover cultivars for 8 weeks after the treatment. Four white clover cv. Regal (large leaf), Louisiana S-I (medium-large leaf), Grasslands Huia (mediumsmall leaf), and Aberystwyth S184 (small leaf), were grown in IOcm plastic pot containing 2:l:l soi1:sand:peat moss mixture until grown to cotyledon or unifoliolate stage and then removed one (Cl) or two cotyledons (C2) at cotyledon stage, and unifoliolate only (U), unifoliolate and one cotyledon (UCl) or unifoliolate and two cotyledons (UC2) at the unifoliolate stage, and the plants were sampled at 4, 6 and 8 weeks after the treatments. The intact plants had greater shoot and root dry weights, and no. of nodules than removal-treated ones. Removal treatments at cotyledon stage, the dry weight and no. of nodules more decreased in C1 and C2 than that of unifoliolate stage. While the severer cotyledon removal, the more reduction. Although the dry weights and no. of nodules steadily inclined with regrowing period, the former were higher in Regal and La. S-1 than in the others since 6 weeks after removal treatment but the latter was more in S 184 than in the others 8 weeks after removal treatment. Relationship between no. of nodules and shoot or root dry weight was analysed as linear mode while the earlier and severe removal, the steeper slope. It was concluded that severer damage of cotyledon and unifoliolate had detrimental effects on the shoot and root growth, nodule formation, and aftermath establishment of white clover.

• 미생물학회지
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• 제24권2호
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• pp.127-132
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• 1986

Soybean nodule extract was prepared and tested for the effectiveness in the induction of asymbiotic nitrogen fixation of R. japonicum P-168. A Asymbiotic nitrogenase activity was increased over twice when glutamate was replaced by nodule extract in the induction media. Independently of the induction media, the nitrogenase activity in the assay media was also enhanced by the addition of nodule extract ($100-400{\mu}g$ protein/ml). The amount of ethylene in the assay media reached the highest point after 8 days incubation of R-168 and was decreased thereafter. The growth of R. japonicum R-168 was sensitive to the concentration of nodule extract. As a while, the effect of soybean root extract was not detected both in the induction of nitrogenase activity and in the growth of R. japonicum R-168.