New insights into plant salt acclimation: the roles of vesicle trafficking and reactive oxygen species signalling in mitochondria and the endomembrane system

• Published in: The New phytologist 2015-01, Vol.205 (1), p.216-239
• Main Authors: Garcia de la Garma, Jesus, Fernandez‐Garcia, Nieves, Bardisi, Enas, Pallol, Beatriz, Asensio‐Rubio, Jose Salvador, Bru, Roque, Olmos, Enrique
• Format: Article
• Language: English
• Subjects: Abscisic acid; Abscisic Acid - metabolism; Acclimation; Acclimatization; Acclimatization - drug effects; Apoptosis - drug effects; Apoptosis - genetics; Caspases - metabolism; Cell death; Cell growth; Cell Line; Cell lines; Cell nucleus; Cells; Chaperones; Cytoplasm; endomembrane system; Endoplasmic reticulum; Fluorescence; Gene Expression Regulation, Plant - drug effects; Glutathione - metabolism; Golgi apparatus; Hydrogen Peroxide - metabolism; Image contrast; Intracellular Membranes - drug effects; Intracellular Membranes - metabolism; Intracellular Membranes - ultrastructure; Malondialdehyde - metabolism; Metabolism; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; Mitochondria - ultrastructure; Molecular modelling; Multidisciplinary research; Nicotiana - cytology; Nicotiana - genetics; Nicotiana - metabolism; Nicotiana - ultrastructure; Nicotiana tabacum; Oxygen; physiological transport; Plant cells; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Proline; Proline - metabolism; Protein folding; Proteins; Proteome - metabolism; Proteomics; Reactive oxygen species; reactive oxygen species (ROS); Reactive Oxygen Species - metabolism; Salt; salt acclimation; Salt Tolerance; Salts; Signal Transduction - drug effects; Signaling; Sodium; Sodium - metabolism; Sodium chloride; Sodium Chloride - pharmacology; stress response; Subcellular Fractions - drug effects; Subcellular Fractions - metabolism; Tobacco; Transcriptome - genetics; transcriptomics; Transport Vesicles - drug effects; Transport Vesicles - metabolism; Transport Vesicles - ultrastructure; unfolded protein response; Vacuoles; vesicle trafficking
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12997

In this study, we investigated the cellular and molecular mechanisms that regulate salt acclimation. The main objective was to obtain new insights into the molecular mechanisms that control salt acclimation. Therefore, we carried out a multidisciplinary study using proteomic, transcriptomic, subcellular and physiological techniques. We obtained a Nicotiana tabacum BY‐2 cell line acclimated to be grown at 258 mM NaCl as a model for this study. The proteomic and transcriptomic data indicate that the molecular response to stress (chaperones, defence proteins, etc.) is highly induced in these salt‐acclimated cells. The subcellular results show that salt induces sodium compartmentalization in the cell vacuoles and seems to be mediated by vesicle trafficking in tobacco salt‐acclimated cells. Our results demonstrate that abscisic acid (ABA) and proline metabolism are crucial in the cellular signalling of salt acclimation, probably regulating reactive oxygen species (ROS) production in the mitochondria. ROS may act as a retrograde signal, regulating the cell response. The network of endoplasmic reticulum and Golgi apparatus is highly altered in salt‐acclimated cells. The molecular and subcellular analysis suggests that the unfolded protein response is induced in salt‐acclimated cells. Finally, we propose that this mechanism may mediate cell death in salt‐acclimated cells.