title: Lipid profiles of detergent resistant fractions of the plasma membrane in oat and rye in association with cold acclimation and freezing tolerance.
abstract: Cold acclimation (CA) results in alteration of the plasma membrane (PM) lipid composition in plants, which plays a crucial role in the acquisition of freezing tolerance via membrane stabilization. Recent studies have indicated that PM structure is consistent with the fluid mosaic model but is laterally non-homogenous and contains microdomains enriched in sterols, sphingolipids and specific proteins. In plant cells, the function of these microdomains in relation to CA and freezing tolerance is not yet fully understood. The present study aimed to investigate the lipid compositions of detergent resistant fractions of the PM (DRM) which are considered to represent microdomains. They were prepared from leaves of low-freezing tolerant oat and high-freezing tolerant rye. The DRMs contained higher proportions of sterols, sphingolipids and saturated phospholipids than the PM. In particular, one of the sterol lipid classes, acylated sterylglycoside, was the predominant sterol in oat DRM while rye DRM contained free sterol as the major sterol. Oat and rye showed different patterns (or changes) of sterols and 2-hydroxy fatty acids of sphingolipids of DRM lipids during CA. Taken together, these results suggest that CA-induced changes of lipid classes and molecular species in DRMs are associated with changes in the thermodynamic properties and physiological functions of microdomains during CA and hence, influence plant freezing tolerance.
authors.affiliation: United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan; Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takahashi
authors.affiliation: Department of Biology, Graduate School of Natural Science, Konan University, Kobe 658-8501, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Imai
authors.affiliation: United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan; Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kawamura
authors.affiliation: United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan; Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan. Electronic address: uemura@iwate-u.ac.jp.
authors.forename: Matsuo
authors.initials: M
authors.lastname: Uemura
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D018554:Avena / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D003902:Detergents / Q000378:metabolism / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism*; D005615:Freezing / Q000009:adverse effects; D008563:Membrane Lipids / Q000378:metabolism*; D021962:Membrane Microdomains / Q000502:physiology; D010743:Phospholipids / Q000378:metabolism*; D018515:Plant Leaves / Q000166:cytology; D012434:Secale / Q000502:physiology*; D013261:Sterols / Q000378:metabolism*
chemical_list: D003902:Detergents; D005227:Fatty Acids; D008563:Membrane Lipids; D010743:Phospholipids; D013261:Sterols
keywords: Cold acclimation; Detergent resistant membrane (microdomain, lipid raft); Freezing tolerance; Oat (Avena sativa); Phospholipid; Plasma membrane; Rye (Secale cereale); Sphingolipid; Sterol