THE EFFECTS OF WATER STRESS ON NITROGEN-FIXING ROOT NODULES I. EFFECTS ON THE PHYSIOLOGY OF DETACHED SOYBEAN NODULES.

When the fresh weight of detached soybean nodules is reduced below 80% of its maximum (fully turgid) value, irreversible changes occur. Acetylene and nitrogen reducing activities cease, respiratory rates become very low and there are gross structural changes. Such nodules are probably shed by the plant. Reduction of water content down to 80% of the maximum fresh weight, leads to a proportionate slowing down of acetylene reduction, with a concomitant reduction in respiratory activity. [ABSTRACT FROM AUTHOR]