Nitrogen nutrition and water stress effects on cell membrane stability and leaf water relations in Agrostis palustris Huds.

The effects of nitrogen nutrition on cell membrane stability (CMS), leaf water potential, N, K, P, Ca, Mg, and glycinebetain concentrations in C-3 plant, Agrostis palustris Huds. (creeping bentgrass) were assessed under water-stress conditions. Water-stressed plants showed greater adaptation to water stress at higher nitrogen (N) levels. Cell membrane stability measured by the polyethylene glycol (PEG) technique was increased by increased N application. Osmotic potential decreased and turgor pressure increased with increased N application. Nitrogen, K, Ca, and glycinebetaine concentrations in leaf tissues increased with increased N application under water-stress conditions. Malondialdehyde (MDA) concentration in leaves which is an indicator of lipid peroxidation, was greater in the water-stress treatment than in the control, however, MDA concentration decreased with increased N application in the water-stressed plants. The results suggested that higher levels of N nutrition may have contributed to drought tolerance in creeping bentgrass by preventing cell membrane damage and enhancing osmoregulation. (C) 2004 Elsevier B.V. All rights reserved.