Homeostasis of plasma membrane viscosity in fluctuating temperatures
Article first published online: 15 JUL 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 192, Issue 2, pages 328–337, October 2011
How to Cite
Martinière, A., Shvedunova, M., Thomson, A. J.W., Evans, N. H., Penfield, S., Runions, J. and McWatters, H. G. (2011), Homeostasis of plasma membrane viscosity in fluctuating temperatures. New Phytologist, 192: 328–337. doi: 10.1111/j.1469-8137.2011.03821.x
- Issue published online: 27 SEP 2011
- Article first published online: 15 JUL 2011
- Received: 15 April 2011, Accepted: 3 June 2011
- circadian rhythm;
- fatty acid;
- plasma membrane;
- temperature sensing;
- •Temperature has a direct effect at the cellular level on an organism. For instance, in the case of biomembranes, cooling causes lipids to lose entropy and pack closely together. Reducing temperature should, in the absence of other factors, increase the viscosity of a lipid membrane. We have investigated the effect of temperature variation on plasma membrane (PM) viscosity.
- •We used dispersion tracking of photoactivated green fluorescent protein (GFP) and fluorescence recovery after photobleaching in wild-type and desaturase mutant Arabidopsis thaliana plants along with membrane lipid saturation analysis to monitor the effect of temperature and membrane lipid composition on PM viscosity.
- •Plasma membrane viscosity in A. thaliana is negatively correlated with ambient temperature only under constant-temperature conditions. In the more natural environment of temperature cycles, plants actively manage PM viscosity to counteract the direct effects of temperature.
- •Plasma membrane viscosity is regulated by altering the proportion of desaturated fatty acids. In cold conditions, cell membranes accumulate desaturated fatty acids, which decreases membrane viscosity and vice versa. Moreover, we show that control of fatty acid desaturase 2 (FAD2)-dependent lipid desaturation is essential for this homeostasis of membrane viscosity. Finally, a lack of FAD2 function results in aberrant temperature responses.