title: Proteome analysis of Physcomitrella patens exposed to progressive dehydration and rehydration.
abstract: Physcomitrella patens is an extremely dehydration-tolerant moss. However, the molecular basis of its responses to loss of cellular water remains unclear. A comprehensive proteomic analysis of dehydration- and rehydration-responsive proteins has been conducted using quantitative two-dimensional difference in-gel electrophoresis (2D-DIGE), and traditional 2-D gel electrophoresis (2-DE) combined with MALDI TOF/TOF MS. Of the 216 differentially-expressed protein spots, 112 and 104 were dehydration- and rehydration-responsive proteins, respectively. The functional categories of the most differentially-expressed proteins were seed maturation, defence, protein synthesis and quality control, and energy production. Strikingly, most of the late embryogenesis abundant (LEA) proteins were expressed at a basal level under control conditions and their synthesis was strongly enhanced by dehydration, a pattern that was confirmed by RT-PCR. Actinoporins, phosphatidylethanolamine-binding protein, arabinogalactan protein, and phospholipase are the likely dominant players in the defence system. In addition, 24 proteins of unknown function were identified as novel dehydration- or rehydration-responsive proteins. Our data indicate that Physcomitrella adopts a rapid protein response mechanism to cope with dehydration in its leafy-shoot and basal expression levels of desiccation-tolerant proteins are rapidly upgraded at high levels under stress. This mechanism appears similar to that seen in angiosperm seeds.
authors: College of Life Sciences, Capital Normal University, Beijing 100048, China. cscoffoni@ucla.edu
authors: Suxia
authors: S
authors: Cui
authors: Jia
authors: J
authors: Hu
authors: Shilei
authors: S
authors: Guo
authors: Jie
authors: J
authors: Wang
authors: Yali
authors: Y
authors: Cheng
authors: Xinxing
authors: X
authors: Dang
authors: Lili
authors: L
authors: Wu
authors: Yikun
authors: Y
authors: He
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D019068:Bryopsida / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D003681:Dehydration; D003890:Desiccation; D015536:Down-Regulation / Q000502:physiology; D005440:Fluid Therapy; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D012639:Seeds / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013312:Stress, Physiological / Q000502:physiology; D053719:Tandem Mass Spectrometry; D057825:Two-Dimensional Difference Gel Electrophoresis; D015854:Up-Regulation / Q000502:physiology; D014867:Water / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D020543:Proteome; C066246:late embryogenesis abundant protein, plant; D014867:Water