Leaf Elongation Rate in Panicum maximum var. trichoglume Following Removal of Water Stress

Abstract

Different levels of stress were induced in P. maximum var. trichoglume by withholding water for various periods. Leaf elongation rate was measured during dark stress periods and after rewatering in both the light and the dark. Following rewatering, elongation rates of previously stressed plants exceeded those of controls for periods up to 33 h, during which time elongation rate was more related to previous levels of water stress than to current leaf water potential. In addition, there was a transient burst of elongation when plants were rewatered in the light. It is suggested that the stimulated rates result from expansion of cells which have accumulated during the stress because cell division is less sensitive to water stress than is cell expansion. Despite the stimulated rates of elongation after rewatering, the recovery was incomplete such that the final lengths of stressed leaves were less than those of unstressed plants.