• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.25-32
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• 1997

This study was carried out to research the biological characteristics among rhizobia and soybean seed and root lectins, and to obtain a basic imformation of host specificity in biological nitrogen symbiosis system. The results obtained were as follows: Purified seed lectin from soybean varieties of paldal, backwoon and hwangkeum formed immunoprecipitin lines with standard soybean seed lectin and the root lectins from soybean seedlings immunoelectrophoretically. Soybean seed and root lectins interacted with Rhizobium japonicum and Bradyrhizobium japonicum, but didn't interacted with Rhizobium. viceae, whereas pea lectin conjugated with R. viceae, but didn't bind with R. japonicum and B. japonicum. Lipopolysaccharides of B. japonicum and R. viceae were fractionated into LPS I and LPS II on the sephadox G-50. Lipopolysaccharides from B. japonicum showed rhe binding acitivity both with soybean seed lectin and root lectin, but those from R. viceae didn't show it with soybean seed and root lectins.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.121-132
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• 1993

This study was carried out to research the effect of the chemotaxis of Bradyrhizobium japonicum KCTC 2422 and its mutant toward soybean root exudate and to elucidate the effect of the lectin of host specificity (Host Recognition) in soybean-Bradyrhizobium symbiosis. The results obtained were as follows: The homogeneities of the purified lectins from soybean and pea seed was ascertained chromatographically and electrophoretically. Gel electrophoresis of soybean lectin in the presence of sodium dodecyl sulfate appeared a single protein band, whereas pea lectin appeared two protein bands. Soybean lectin from 2 cultivars formed immunoprecipitin arcs at same position with anti-soybean lectin rabbit IgG, but pea lectin did not form immunoprecipitin lines with anti-soybean lectin rabbit IgG. Chemotactic responses of KCTC 2422, LPN-100 and LCR-101 toward proline in capillary assays were 3.1, 1.3 and 1.0-fold above background, respectively. The chemotactic responses of KCTC 2422, LPN-100, and LCR-101 toward Paldal crude root exudate in capillary assays were 3.5, 1.4 and 1.4-fold above background, respectively. The present work shows that B. japonicum and its mutants are capable of very different responses toward root exudate fraction. The chemotactic responses of KCTC 2422 was most with neutral fraction, least with anionic fraction and intermediate with cationic fraction. The nitrogenase activity of soybean nodule was shown in 15days after inoculation with LCR-101. However, we couldn't find out the nodules when soybean was inoculated with LPN-100. From these result we can suppose that the chemotaxis of Bradyrhizobium plays inportant the role of forming the nodule (host recognition) in the soybean-B. japonicum symbiosis.