title: Label-free quantitative proteomics to investigate strawberry fruit proteome changes under controlled atmosphere and low temperature storage.
abstract: To elucidate the mechanisms contributing to fruit responses to senescence and stressful environmental stimuli under low temperature (LT) and controlled atmosphere (CA) storage, a label-free quantitative proteomic investigation was conducted in strawberry (Fragaria ananassa, Duch. cv. 'Akihime'). Postharvest physiological quality traits including firmness, total soluble solids, total acidity, ascorbic acid and volatile production were characterized following storage under different conditions. The observed post-storage protein expression profiles may be associated with delayed senescence features in strawberry. A total of 454 proteins were identified in differentially treated strawberry fruits. Quantitative analysis, using normalized spectral counts, revealed 73 proteins common to all treatments, which formed three clusters in a hierarchical clustering analysis. The proteins spanned a range of functions in various metabolic pathways and networks involved in carbohydrate and energy metabolism, volatile biosynthesis, phenylpropanoid activity, stress response and protein synthesis, degradation and folding. After CA and LT storage, 16 (13) and 11 (17) proteins, respectively, were significantly increased (decreased) in abundance, while expression profile of 12 proteins was significantly changed by both CA and LT. To summarize, the differential variability of abundance in strawberry proteome, working in a cooperative manner, provided an overview of the biological processes that occurred during CA and LT storage.
  
  
  CONCLUSIONS
  Controlled atmosphere storage at an optimal temperature is regarded to be an effective postharvest technology to delay fruit senescence and maintain fruit quality during shelf life. Nonetheless, little information on fruit proteomic changes under controlled atmosphere and/or low temperature storage is available. The significance of this paper is that it is the first study employing a label-free approach in the investigation of strawberry fruit response to controlled atmosphere and cold storage. Changes in postharvest physiological quality traits including volatile production, firmness, ascorbic acid, soluble solids and total acidity were also characterized. Significant biological changes associated with senescence were revealed and differentially abundant proteins under various storage conditions were identified. Proteomic profiles were linked to physiological aspects of strawberry fruit senescence in order to provide new insights into possible regulation mechanisms. Findings from this study not only provide proteomic information on fruit regulation, but also pave the way for further quantitative studies at the transcriptomic and metabolomic levels.
authors.affiliation: Key Laboratory of Food Nutrition and Safety (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Food Science and Nutrition, Zhejiang University, Hangzhou, Zhejiang 310058, PR China.
authors.forename: Zisheng
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Key Laboratory of Food Nutrition and Safety (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China.
authors.forename: Xinhong
authors.initials: X
authors.lastname: Huang
authors.affiliation: Key Laboratory of Food Nutrition and Safety (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Food Nutrition and Safety (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Food Nutrition and Safety (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Food Nutrition and Safety (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China. Electronic address: Jimmy.li1011@gmail.com.
authors.forename: Xihong
authors.initials: X
authors.lastname: Li
authors.affiliation: Jinan Fruit Research Institute, All China Federation of Supply and Marketing Cooperatives, Jinan, Shandong 250014, PR China; College of Forestry and Horticulture, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, PR China.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Ban
authors.affiliation: Key Laboratory of Food Nutrition and Safety (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China.
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
mesh_terms: D001272:Atmosphere; D003080:Cold Temperature; D005504:Food Analysis / Q000379:methods*; D061353:Food Storage / Q000379:methods; D031985:Fragaria / Q000378:metabolism*; D005638:Fruit / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods; D018869:Heat-Shock Response / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D020543:Proteome
keywords: Controlled atmosphere; Fruit; LC–MS/MS; Storage; Strawberry; Volatiles