title: Comparative proteomic and metabolomic analyses reveal mechanisms of improved cold stress tolerance in bermudagrass (Cynodon dactylon (L.) Pers.) by exogenous calcium.
abstract: As an important second messenger, calcium is involved in plant cold stress response, including chilling (<20 °C) and freezing (<0 °C). In this study, exogenous application of calcium chloride (CaCl2 ) improved both chilling and freezing stress tolerances, while ethylene glycol-bis-(β-aminoethyl) ether-N,N,N,N-tetraacetic acid (EGTA) reversed CaCl2 effects in bermudagrass (Cynodon dactylon (L.) Pers.). Physiological analyses showed that CaCl2 treatment alleviated the reactive oxygen species (ROS) burst and cell damage triggered by chilling stress, via activating antioxidant enzymes, non-enzymatic glutathione antioxidant pool, while EGTA treatment had the opposite effects. Additionally, comparative proteomic analysis identified 51 differentially expressed proteins that were enriched in redox, tricarboxylicacid cycle, glycolysis, photosynthesis, oxidative pentose phosphate pathway, and amino acid metabolisms. Consistently, 42 metabolites including amino acids, organic acids, sugars, and sugar alcohols were regulated by CaCl2 treatment under control and cold stress conditions, further confirming the common modulation of CaCl2 treatment in carbon metabolites and amino acid metabolism. Taken together, this study reported first evidence of the essential and protective roles of endogenous and exogenous calcium in bermudagrass response to cold stress, partially via activation of the antioxidants and modulation of several differentially expressed proteins and metabolic homeostasis in the process of cold acclimation.
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, the Chinese Academy of Sciences, Wuhan, 430074, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Shi
authors.forename: Tiantian
authors.initials: T
authors.lastname: Ye
authors.forename: Bao
authors.initials: B
authors.lastname: Zhong
authors.forename: Xun
authors.initials: X
authors.lastname: Liu
authors.forename: Zhulong
authors.initials: Z
authors.lastname: Chan
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000975:Antioxidants / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D057486:Carbon Cycle / Q000187:drug effects; D003080:Cold Temperature; D031744:Cynodon / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology; D005615:Freezing; D006706:Homeostasis / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D055432:Metabolomics / Q000379:methods*; D008954:Models, Biological; D010788:Photosynthesis / Q000187:drug effects; D010940:Plant Proteins / Q000378:metabolism; D020543:Proteome / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D010940:Plant Proteins; D020543:Proteome; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D004533:Egtazic Acid; D002118:Calcium
keywords: Antioxidant; bermudagrass; calcium; chilling; freezing; metabolite; proteomic