title: Differential degradation of extraplastidic and plastidic lipids during freezing and post-freezing recovery in Arabidopsis thaliana.
abstract: Changes in membrane lipid composition play important roles in plant adaptation to and survival after freezing. Plant response to cold and freezing involves three distinct phases: cold acclimation, freezing, and post-freezing recovery. Considerable progress has been made toward understanding lipid changes during cold acclimation and freezing, but little is known about lipid alteration during post-freezing recovery. We previously showed that phospholipase D (PLD) is involved in lipid hydrolysis and Arabidopsis thaliana freezing tolerance. This study was undertaken to determine how lipid species change during post-freezing recovery and to determine the effect of two PLDs, PLDalpha1 and PLDdelta, on lipid changes during post-freezing recovery. During post-freezing recovery, hydrolysis of plastidic lipids, monogalactosyldiacylglycerol and plastidic phosphatidylglycerol, is the most prominent change. In contrast, during freezing, hydrolysis of extraplastidic phospholipids, phosphatidylcholine and phosphatidylethanolamine, occurs. Suppression of PLDalpha1 decreased phospholipid hydrolysis and phosphatidic acid production in both the freezing and post-freezing phases, whereas ablation of PLDdelta increased lipid hydrolysis and phosphatidic acid production during post-freezing recovery. Thus, distinctly different changes in lipid hydrolysis occur in freezing and post-freezing recovery. The presence of PLDalpha1 correlates with phospholipid hydrolysis in both freezing and post-freezing phases, whereas the presence of PLDdelta correlates with reduced lipid hydrolysis during post-freezing recovery. These data suggest a negative role for PLDalpha1 and a positive role for PLDdelta in freezing tolerance.
authors.affiliation: Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650204, China. Electronic address: weiqili@mail.kib.ac.cn.
authors.forename: Weiqi
authors.initials: W
authors.lastname: Li
authors.affiliation: Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650204, China.
authors.forename: Ruiping
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Biology, University of Missouri and Donald Danforth Plant Science Center, St. Louis, Missouri 63121.
authors.forename: Maoyin
authors.initials: M
authors.lastname: Li
authors.affiliation: Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650204, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Biology, Honghe University, Mengzi, Yunnan 661100, China.
authors.forename: Chuanming
authors.initials: C
authors.lastname: Wang
authors.affiliation: Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, Kansas 66506.
authors.forename: Ruth
authors.initials: R
authors.lastname: Welti
authors.affiliation: Department of Biology, University of Missouri and Donald Danforth Plant Science Center, St. Louis, Missouri 63121.
authors.forename: Xuemin
authors.initials: X
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D016000:Cluster Analysis; D005615:Freezing; D006868:Hydrolysis; D008055:Lipids / Q000737:chemistry*; D008954:Models, Biological; D009154:Mutation; D010712:Phosphatidic Acids / Q000032:analysis / Q000737:chemistry; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis / Q000737:chemistry; D018087:Plastids / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D029681:Arabidopsis Proteins; D008055:Lipids; D010712:Phosphatidic Acids; D010743:Phospholipids; C446530:phospholipase D delta; D010739:Phospholipase D