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ARS Home » Midwest Area » Urbana, Illinois » Soybean/maize Germplasm, Pathology, and Genetics Research » Research » Publications at this Location » Publication #72797
Title: CHANGES IN CONCENTRATION OF LEGHEMOGLOBIN COMPONENTS IN HYPERNODULATING MUTANTS OF SOYBEAN

Author
item NISHIWAKI, T - NIIGATA U, JAPAN
item SATO, T - NIIGATA U, JAPAN
item YASHIMA, H - NIIGATA U, JAPAN
item IKARASHI, T - NIIGATA U, JAPAN
item OHYAMA, T - NIIGATA U, JAPAN
item Harper, James
item AKAO, S - AG-BIO RES, TSUKUBA, JA
item KOUCHI, H - AG-BIO RES, TSUKUBA, JA

Submitted to: Plant Nutrition Colloquium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/12/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Leghemoglobin (Lb) plays a crucial role in nitrogen fixation of soybean (Glycine max L. Merr.) nodules by facilitating O2 supply to the bacteroids. The concentration and composition of Lb components in hypernodulating mutant lines NOD1-3, NOD2-4, and NOD3-7 from cv. Williams, and En6500 from cv. Enrei, were compared in relation to their nodulation characteristics. Plants were hydroponically cultivated in N free culture solution and the nodules were separated by their size. Concentration and composition of Lb components in the same size nodules were analyzed by gel-electrophoresis or capillary electrophoresis. In all the NOD mutants Lb concentration was about 30% lower than in the parent Williams irrespective of nodule size and growth stage. In the hypernodulating mutant En6500, total Lb concentration was only one fourth that in the parent line Enrei, irrespective of nodule size. In Enrei nodules, the relative concentration of Lba, c1, c2, and c3 was 39, 26, 18, and 17%, respectively, and very stable irrespective of nodule size. En6500 had relatively equal amount of each component (concentrations of Lba, c1, c2, and c3, were 30, 22, 22, and 26%, respectively). The concentrations of Lb components, especially c1 and c2 in Enrei nodules, were decreased by addition of nitrate. The result that Lb concentration was lower in hypernodulating mutant lines than their parents indicated that hypernodulating lines could not maintain the maximum nodule growth and function. This may be due to shortage of nutrient (such as carbohydrates) supply to support excess nodulation expression in absence of autoregulatory control.