Changes in concentration of leghemoglobin components in hypernodulation mutants of soybean

Possible involvement of photosynthetic supply in changes of nodule characteristics of hypernodulating soybeans

“…The concentration of the Lb components in the control Enrei, the shoot-cut Enrei and the normally nodulating En6500 markedly decreased by the + N treatment. In this experiment, the total Lb concentration changed more considerably by a higher concentration of nitrate (5 mM) in the nitrate treatment compared with the previous experiment with 2 mM N0 3 - (Nishiwaki et al 1997). Since the total Lb concentration was positively correlated with the ARA per nodule dry weight (data not shown), the Lb concentration may be one of the limiting factors in the nitrogen fixation activity.…”

“…Although hypernodulating mutant lines have a large number of nodules, the nodules exhibited a low specific acetylene reduction activity based on the nodule dry weight in En6500 (Takahashi et al 1995). It was also observed that the NOD mutant lines had a low proportion of infected region compared with the parent Williams (Nishiwaki et al 1997). Moreover, both hypernodulating mutants En6500 and NODl-3 showed a lower Lb concentration in the nodules compared with their parent nodules (Sato et al 1998).…”

“…Moreover, both hypernodulating mutants En6500 and NODl-3 showed a lower Lb concentration in the nodules compared with their parent nodules (Sato et al 1998). Also the Lb component ratios in the nodules of the hypernodulating mutant NODI-3 were different from those of its parent Williams (Nishiwaki et al 1997). The difference in the characteristics of the nodules of the hypernodulating mutants can be ascribed to the fact that the expression of the related genes is directly altered by mutation~ or due to the large number of nodules (Hansen 1994).…”

“…The Lb in the soybean nodules has four major components, that is Lba, Lbcl, Lbc2, and Lbc3 (Appleby 1974), but the differences in their expression and their function have not been elucidated. We have reported that the Lb concentration changed with the nodule size and decreased by exogenous nitrate supply (Nishiwaki et al 1997). Lb concentration and component ratio in the nodules may be involved in the nodule growth and nitrogen fixation activity.…”

Effect of Nitrate on Nodule and Root Growth of Soybean (Glycine max (L.) Merr.)

“…Nishiwaki et al . [ 43 ] and Sato et al . [ 44 ] determined the concentration of the leghemoglobin components, Lba, Lbc 1 , Lbc 2 , and Lbc 3 , and showed that these concentrations were lower in nodules supplied with 5 mM nitrate than in those supplied with 0 mM nitrate.…”