Temperature dependence of the permeability of chloroplasts from chilling-sensitive and chilling-resistant plants.
Osmotic responses of chloroplasts from chilling-resistant (Pisum sativum L., Spinacia oleracea L.) and chilling-sensitive (Phaseolus vulgaris L., Lycopersicon esculentum Mill.) plants to glycerol and erythritol were determined from 1° to 28°. The permeability of the chloroplast limiting membranes, as measured by reflection coefficients, decreased when the temperature was raised. For Pisum and Spinacia the curves relating reflection coefficients and temperature were smooth, while for Phaseolus and Lycopersicon breaks occurred near 11°. The break may indicate a phase transition in the membranes, the change leading to a higher chloroplast permeability at lower temperatures for chilling-sensitive plants.
Department of Biology, University of California, 90024, Los Angeles, California, USA.
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Nobel