• Journal of Ecology and Environment
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• v.29 no.2
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• pp.151-155
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• 2006

Root nodule biomass, and seedling biomass and growth were examined for 2-year-old Robinia pseudoacacia and Amorpha fruticosa seedlings following fertilization treatments. Organic fertilizer, solid combination fertilizer, and organic fertilizer plus solid combination fertilizer were used for the study. Root nodule biomass (g/plant) ranged from 3.00 to 7.06 for R. pseudoacacia and varied from 1.52 to 2.32 for A. fruticosa, respectively. In all treatments, root nodule biomass of R. pseudoacacia was significantly higher than those of A. fruticosa. Fertilization significantly increased root nodule biomass for only R. pseudoacacia, however, there were no significant differences in root nodule biomass among fertilization treatments. Root nodule biomass was not influenced by soil nitrogen (N) and phosphorous (P) concentrations following fertilization treatments. Seedling biomass (components and total) and growth (diameter at root collar and height) were strongly correlated with root nodule biomass for the two N fixing tree species.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.493-502
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• 1995

Nodulation phenology in relation to plant phenology, vertical distribution of nodul and root biomass in different soil, correlation between nodule and root size, and nitrogen mineralization around the rhizosphere by ion-exchange resin bag buried at 10 cm of soil were studied in Elaeagnus nmbellata (autumn-olive) stand, Korea. Nodulation appeared from spring to autumn and nodule phenology was coincided with the timing of root activity rather than that of foliation. Nodul size increased in proportion to the root size. In the sand dune with the lower root biomass, nodule appeared up to 80 cm deep in soil and the nodule biomass was 1,070 kg/ha, which was the highest value reported for several actinorhizal plants in the temperate regions. It is suggested that nodule distribution and production are mainly influenced by soil aeration among environmental factors. The higher ammonification or lower nitrification rate contrasted markedly with the earlier studies that reported lower ammonification or higher nitrification in actinorhizal plant soil. Nitrogen mineralization rate around the rhizosphere with root and nodule was characterized by higher nitrification rate than that in the control soil without root and nodule.

• Journal of Plant Biology
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• v.32 no.1
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• pp.1-9
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• 1989

An endophyte was isolated from the root nodule of alnus hirsuta. The isolated endophyte was identified as a Frankia sp. through morphological characteristics. Their infectivity and effectivity were confirmed by nitrogen-fixing root nodules induced on inoculated Alnus seedlings. Reisolated endophyte from the induced nodule showed identical morphological characteristics as the first isolate, showing the nodule was induced by the first isolate. Consequently, the first isolate was confirmed as a true symbiont of Almus hirsuta root nodule. The isolate was designated as a Frankia SNU 014201 strain.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.398-403
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• 1989

The root nodule of Canavalia lineta was classified as a determinate nodule and the symbiont as a Rhizobium-bacteriod based on their morphological characteristics. Isolated encosymbiont was similar both to R. leguminosarum and R. meliloti in its peritrichous arrangement of flagella and some of the physiological characteristics. Compared to control plants, Canavalia seedlings inoculated with the isolate grew normally due to induced root nodules, confirming isolate's infectivity and effectivity. Characteristics of the reisolated endosymbiont from induced root nodule were identical to those of the first isolate, indicating the nodules were induced by the first isolate. From these results, it was confirmed that Rhizobium strain isolated from the root nodules of Canavalia lineata was a real symbiont, and was named Rhizobium sp. SNU003.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.28-31
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• 1998

Nodule development was regulated partially by host plant factors originating in the shoots and roots. This study was performed to identify the origin of the factors regulating nodulation in supernodulating soybean (Glycine max [L.] Merr.) mutant 'SS2-2' which was isolated recently from ethyl methanesulfonate (EMS) mutagenesis of 'Sinpaldalkong 2'. Self- and reciprocal-grafts were made among three soybean genotypes which consisted of two supernodulating mutants, SS2-2 and 'nts 382', and a normal nodulating Sinpaldalkong 2. Self-grafted supernodulating mutants were characterized by greater nodule number, nodule dry weight, and $C_2$H$_2$ reduction activity than self-grafted wild types. They were also characterized by relatively higher nodule to root dry weight. Significant shoot genotypic effects were observed on nodule number, nodule dry weight, and $C_2\;H_2$ reduction activity per plant, whereas varying root genotypes had no effects. From this result, it is surmised that supernodulating characters are controlled by a graft-transmissible shoot factor, and mutant SS2-2 may have similar nodulation mechanism to the former supernodulating nts 382. In all grafts, both supernodulating mutants and Sinpaldalkong 2 maintained the similar balance between above ground and below ground parts regardless of significant differences in partitioning of dry matter into root and nodule between supernodulating mutants and Sinpaldalkong 2.

• Journal of Plant Biology
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• v.36 no.3
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• pp.301-304
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• 1993

Root nodule specific proteins of Alnus hirsuta were examined. SDS-PAGE pattern of the Alnus root nodule was simpler than that of soybean, showing five nodule specific proteins whose molecular weights were 48, 40, 36, 26 and 19 kD, respectively. Among them, 48 kD protein existed most abundantly and were composed of two subunits whose pI value were 4.0 and 4.3, respectively. The 48 kD protein seemed to be a heme containing protein based on reaction with diaminobenzidine. Although 19 kD protein was present in small amount, it was most similar to leghemoglobin in terms of its molecular weight.

• The Plant Pathology Journal
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• v.15 no.2
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• pp.127-130
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• 1999

Cytological changes of cowpea root at the early stage of root nodule formation (within 5 days after inoculation) were viewed by light and electron microscopy. The root region affected by the rhizobial infection, which was composed of a redial array of cortical cells, had prominent cell divisions, mostly anticlinal in the inner cortical cells and in addition oblique and periclinal in the outer cells. An infected root hair cell (or root hair-producing epidermal cell) had numerous infection threads and degenerated cytoplasm. Module meristem was formed adjacent to the infected root hair cell, and characterized by dense cytoplasm, prominent nucleus, numerous small vacuoles, and increased plastids, containing infection threads as well. Bacterial cells were dividing inside the infection thread, the wall materials of which appeared to be dissolved ad accumulated in small vacuoles. inner cortical cells contiguous to the nodule meristem appeared to be actively dividing and dedifferentiating; however, they were not infected by the rhizobia. These structural characteristics are similar to those in the Bradyrhizobium-soybean association previously reported, and may reflect the similar cytological process in cowpea in the early nodule formation.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.455-461
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• 1988

The pattern of nitrogen fixation by water culture of Sesbania, known as an effective legume plant for nitrogen fixation, in the growth cabinet by Leonard-Jar methods and nitrogen fixation pattern to sesbania are as follows: 1. Dry weight per pot after inoculation of rhizobia to sesbania was by the order for root + stem > root > control and nitrogen contents of plant parts also showed the same tendency as dry weight except leaf. 2. $^{15}N$ value based on natural abundance was by the order of root + stem > root > control, $^{15}N$ value of root nodule and stem nodule among total nitrogen content exhibited positive value but it showed negative value from root, stem and leaf.

• Journal of Plant Biology
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• v.36 no.2
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• pp.177-182
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• 1993

The root nodules of Elaeagnus umbellata were coralloid-shape due to repeated dichotomous branching of nodule meristem. The filamentous endophyte with vesicle cluster ranging from 30 ${\mu}{\textrm}{m}$ to 60 ${\mu}{\textrm}{m}$ in diameter was present only in the cortical cells. The isolated endophytes in vitro culture showed typical Frankia morphology, consisting of highly branched hyphae ranging from 0.8 ${\mu}{\textrm}{m}$ to 1.0 ${\mu}{\textrm}{m}$ in diameter, terminal and intrahyphal sporangia varing in shape and size up to 60 ${\mu}{\textrm}{m}$ in length and laminated vesicles. Its infectivity and effectivity were confirmed by induction of nitrogen-fixing root nodules on the inoculated seedlings of two Elaeagnus species. Consequently, the isolate was confirmed as a true symbiont of Elaeagnus umbellata root nodule and named Frankia EuIK1.

• Journal of Plant Biology
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• v.34 no.2
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• pp.121-127
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• 1991

Total soluble proteins from three developmental stages of induced root nodules of Canavalia lineata were compared with those of non-nodulated roots by SDS-PAGE and two dimensional (2-D) gel electrophoresis. Thirteen nodule-specific protein (nodulin) bands were identified by the former and 30 nodule specific protein spots were detected by the latter method respectively. Some of the nodulins were detected differentially depending on the nodule's developmental stages. For example, only three leghemoglobin (Lb)-like protein spots appeared at stage I (d<2 mm), but two additional Lb-like protein spots appeared at stage II (d <4-5 mm). pI value and molecular weight of nomomers of Lb-like protein were narrower and greater than those of soybean, ranging from 4.4 to 5.0 and 15.7 kd respectively. Northern blot hybridization of total RNAs from roots and root nodules using soybean Lb cDNA as a probe made it clear that Lb gene was expressed tissue-specifically only in the root nodules.odules.