title: Comparative proteomic analysis reveals the positive effect of exogenous spermidine on photosynthesis and salinity tolerance in cucumber seedlings.
abstract: Our results based on proteomics data and physiological alterations proposed the putative mechanism of exogenous Spd enhanced salinity tolerance in cucumber seedlings. Current studies showed that exogenous spermidine (Spd) could alleviate harmful effects of salinity. It is important to increase our understanding of the beneficial physiological responses of exogenous Spd treatment, and to determine the molecular responses underlying these responses. Here, we combined a physiological analysis with iTRAQ-based comparative proteomics of cucumber (Cucumis sativus L.) leaves, treated with 0.1 mM exogenous Spd, 75 mM NaCl and/or exogenous Spd. A total of 221 differentially expressed proteins were found and involved in 30 metabolic pathways, such as photosynthesis, carbohydrate metabolism, amino acid metabolism, stress response, signal transduction and antioxidant. Based on functional classification of the differentially expressed proteins and the physiological responses, we found cucumber seedlings treated with Spd under salt stress had higher photosynthesis efficiency, upregulated tetrapyrrole synthesis, stronger ROS scavenging ability and more protein biosynthesis activity than NaCl treatment, suggesting that these pathways may promote salt tolerance under high salinity. This study provided insights into how exogenous Spd protects photosynthesis and enhances salt tolerance in cucumber seedlings.
authors.affiliation: Key Laboratory of Southern Vegetables Genetic Improvement of Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Sang
authors.affiliation: Key Laboratory of Southern Vegetables Genetic Improvement of Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Shan
authors.affiliation: Key Laboratory of Southern Vegetables Genetic Improvement of Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory of Southern Vegetables Genetic Improvement of Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Shu
authors.affiliation: Key Laboratory of Southern Vegetables Genetic Improvement of Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.|Facility Horticulture Institute, Nanjing Agricultural University, Suqian, Jiangsu, 223800, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Sun
authors.affiliation: Key Laboratory of Southern Vegetables Genetic Improvement of Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. srguo@njau.edu.cn.|Facility Horticulture Institute, Nanjing Agricultural University, Suqian, Jiangsu, 223800, China. srguo@njau.edu.cn.
authors.forename: Shirong
authors.initials: S
authors.lastname: Guo
mesh_terms: D016000:Cluster Analysis; D018553:Cucumis sativus / Q000187:drug effects / Q000502:physiology*; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D008954:Models, Biological; D010788:Photosynthesis / Q000187:drug effects*; D063245:Plant Development / Q000187:drug effects; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D018520:Plant Shoots / Q000187:drug effects / Q000502:physiology; D040901:Proteomics / Q000379:methods*; D055049:Salt Tolerance / Q000187:drug effects*; D036226:Seedlings / Q000187:drug effects / Q000502:physiology*; D013095:Spermidine / Q000494:pharmacology*
chemical_list: D010940:Plant Proteins; D013095:Spermidine
keywords: Cucumis sativus L; Photosynthesis; Proteomics; Salinity; Spermidine