Changes in Membrane Permeability of Winter Wheat Cells Following Freeze-Thaw Injury as Determined by Nuclear Magnetic Resonance

• Published in: Plant physiology (Bethesda) Vol. 61; no. 6; pp. 878 - 882
• Main Authors: Chen, P M, Gusta, L V
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Physiologists 01.06.1978
• Subjects: Acclimatization; Cell aggregates; Cell membranes; Freezing; Liquids; Nuclear magnetic resonance; Plant tissues; Plants; Protons; Relaxation time
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.61.6.878

Nuclear magnetic resonance (NMR) relaxation times were studied in acclimated and nonacclimated Kharkov winter wheat (Triticum aestivum L.) crowns and acclimated cell aggregates to determine if membrane permeability was altered by freezing. The NMR water signal decay consisted of two exponential components: a short one arising from extracellular water, and a long one arising from intracellular water. A slow freeze-thaw treatment of nonacclimated and 1-week acclimated crowns decreased the long relaxation time, suggesting membrane injury. Similar results were obtained for nonacclimated and acclimated crowns killed directly in liquid N2. A significant increase in plasma membrane permeability to Mn2+ was observed in acclimated freeze-killed crowns and cell aggregates. Freezing injury to plant tissue appears to be a membrane-related phenomenon, but more extensive injury occurs to nonacclimated and acclimated tissue with a high water content (cell aggregates) compared to acclimated tissue with a low water content (crowns).