Osmoregulation in plants during drought.

Abstract

For higher plants, water deficiency is more commonly caused by a lack of sufficient water than by exposure to high concentrations of solutes. Crop production is frequently limited by this factor and certain stages of development are more sensitive than others. A particularly sensitive time is during germination. The plant has little root and is located in a layer of soil that quickly dehydrates. Growth must continue, however, since the plant must become autotrophic. The possibility that osmoregulation may protect against the inhibitory effects of dry soil has not been explored during germination (Meyer and Boyer, 1972). In the present paper, we will describe a highly developed system of osmoregulation that permits seedling growth under dry soil conditions that would otherwise be lethal for the plant.