title: Proteomic and phosphoproteomic analysis of polyethylene glycol-induced osmotic stress in root tips of common bean (Phaseolus vulgaris L.).
abstract: Previous studies have shown that polyethylene glycol (PEG)-induced osmotic stress (OS) reduces cell-wall (CW) porosity and limits aluminium (Al) uptake by root tips of common bean (Phaseolus vulgaris L.). A subsequent transcriptomic study suggested that genes related to CW processes are involved in adjustment to OS. In this study, a proteomic and phosphoproteomic approach was applied to identify OS-induced protein regulation to further improve our understanding of how OS affects Al accumulation. Analysis of total soluble proteins in root tips indicated that, in total, 22 proteins were differentially regulated by OS; these proteins were functionally categorized. Seventy-seven per- cent of the total expressed proteins were involved in metabolic pathways, particularly of carbohydrate and amino acid metabolism. An analysis of the apoplastic proteome revealed that OS reduced the level of five proteins and increased that of seven proteins. Investigation of the total soluble phosphoproteome suggested that dehydrin responded to OS with an enhanced phosphorylation state without a change in abundance. A cellular immunolocalization analysis indicated that dehydrin was localized mainly in the CW. This suggests that dehydrin may play a major protective role in the OS-induced physical breakdown of the CW structure and thus maintenance of the reversibility of CW extensibility during recovery from OS. The proteomic and phosphoproteomic analyses provided novel insights into the complex mechanisms of OS-induced reduction of Al accumulation in the root tips of common bean and highlight a key role for modification of CW structure.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Science, Shandong University, Jinan 250100, PR China.
authors.forename: Zhong-Bao
authors.initials: ZB
authors.lastname: Yang
authors.forename: Dejene
authors.initials: D
authors.lastname: Eticha
authors.forename: Hendrik
authors.initials: H
authors.lastname: Führs
authors.forename: Dimitri
authors.initials: D
authors.lastname: Heintz
authors.forename: Daniel
authors.initials: D
authors.lastname: Ayoub
authors.forename: Alain
authors.initials: A
authors.lastname: Van Dorsselaer
authors.forename: Barbara
authors.initials: B
authors.lastname: Schlingmann
authors.forename: Idupulapati Madhusudana
authors.initials: IM
authors.lastname: Rao
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Braun
authors.forename: Walter Johannes
authors.initials: WJ
authors.lastname: Horst
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002473:Cell Wall / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D009997:Osmotic Pressure; D027805:Phaseolus / Q000187:drug effects / Q000502:physiology*; D010750:Phosphoproteins / Q000032:analysis / Q000378:metabolism*; D010940:Plant Proteins / Q000032:analysis / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology; D040901:Proteomics / Q000379:methods
chemical_list: D000596:Amino Acids; D010750:Phosphoproteins; D010940:Plant Proteins; C070556:dehydrin proteins, plant; D011092:Polyethylene Glycols
keywords: Apoplast; cell wall; common bean; dehydrin; phosphoproteomics; proteomics; root tips.