Main content area

Effects of salt stress on nitrogen fixation, oxygen diffusion, and ion distribution in soybean, common bean, and alfalfa

Serraj, R., Vasquez-Diaz, H., Drevon, J.J.
Journal of plant nutrition 1998 v.21 no.3 pp. 475-488
reduction, acetylene, Glycine max, Phaseolus vulgaris, Medicago sativa, cultivars, Bradyrhizobium japonicum, Rhizobium leguminosarum, Sinorhizobium meliloti, salinity, nitrogen fixation, ion transport, sodium chloride, nitrogenase, enzyme activity, diffusion, root nodules, gas exchange, biomass, leaves, stems, roots, potassium chloride, magnesium, sodium, inorganic ions, calcium, chemical constituents of plants, species differences, root shoot ratio
The exposure of legume nodulated-roots to 100 mM NaCl resulted in a rapid decrease in plant growth associated with a short-term inhibition of both nodule growth and nitrogenase activity (C2H2 reduction=ARA). However, these NaCl effects varied among species, common bean being more sensitive than soybean and alfalfa. The higher sensitivity of common bean was associated with a higher accumulation of sodium (Na) and chlorine (Cl) in the nodules and only a small difference between salt-treated and control plants of common bean in their responses of ARA to raising rhizosphere PO2. By contrast, soybean and alfalfa plants showed a higher stimulation of ARA by PO2 for the salt-treatment than for the control. It is concluded that the intraspecific variation in short-term inhibition of ARA by salt may involve the regulation of O2 diffusion and the distribution of ions in nodules.