title: Physiological and iTRAQ-Based Proteomic Analyses Reveal the Function of Spermidine on Improving Drought Tolerance in White Clover.
abstract: Endogenous spermidine interacting with phytohormones may be involved in the regulation of differentially expressed proteins (DEPs) associated with drought tolerance in white clover. Plants treated with or without spermidine (50 μM) were subjected to 20% PEG 6000 nutrient solution to induce drought stress (50% leaf-relative water content). The results showed that increased endogenous spermidine induced by exogenous spermidine altered endogenous phytohormones in association with improved drought tolerance, as demonstrated by the delay in water-deficit development, improved photosynthesis and water use efficiency, and lower oxidative damage. As compared to untreated plants, Spd-treated plants maintained a higher abundance of DEPs under drought stress involved in (1) protein biosynthesis (ribosomal and chaperone proteins); (2) amino acids synthesis; (3) the carbon and energy metabolism; (4) antioxidant and stress defense (ascorbate peroxidase, glutathione peroxidase, and dehydrins); and (5) GA and ABA signaling pathways (gibberellin receptor GID1, ABA-responsive protein 17, and ABA stress ripening protein). Thus, the findings of proteome could explain the Spd-induced physiological effects associated with drought tolerance. The analysis of functional protein-protein networks further proved that the alteration of endogenous spermidine and phytohormones induced the interaction among ribosome, photosynthesis, carbon metabolism, and amino acid biosynthesis. These differences could contribute to improved drought tolerance.
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu 611130, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu 611130, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University , 59 Dudley Road, New Brunswick, New Jersey 08901, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu 611130, China.
authors.forename: Xinquan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu 611130, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu 611130, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu 611130, China.
authors.forename: Linkai
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Grassland Science, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu 611130, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Yan
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D055864:Droughts; D029902:Medicago / Q000502:physiology*; D010937:Plant Growth Regulators / Q000032:analysis; D060066:Protein Interaction Maps / Q000187:drug effects; D040901:Proteomics / Q000379:methods*; D013095:Spermidine / Q000494:pharmacology*
chemical_list: D010937:Plant Growth Regulators; D013095:Spermidine
keywords: differentially expressed proteins; gene expression; hormone; metabolic pathway; photosynthesis; polyamine