title: Salt adaptation requires efficient fine-tuning of jasmonate signalling.
abstract: Understanding the mechanism by which plants sense, signal and respond to salinity stress is of great interest to plant biologists. In stress signalling, often the same molecules are involved in both damage-related and adaptive events. To dissect this complexity, we compared the salinity responses of two grapevine cell lines differing in their salinity tolerance. We followed rapid changes in the cellular content of sodium and calcium, apoplastic alkalinisation and slower responses in the levels of jasmonic acid, its active isoleucine conjugate and abscisic acid, as well as of stilbenes. Differences in timing and sensitivity to either the lanthanoid Gd or exogenous calcium provide evidence for an adaptive role of early sodium uptake through non-selective cation channels acting upstream of Ca(2+) and H(+) fluxes. We find a correlation of salt sensitivity with unconstrained jasmonate (JA) signalling, whereas salt adaptation correlates with tight control of jasmonic acid and its isoleucine conjugate, accompanied by accumulation of abscisic acid and suppression of stilbenes that trigger defence-related cell death. The data are discussed by a model where efficient fine-tuning of JA signalling determines whether cells will progress towards adaptation or programme cell death.
authors.affiliation: Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany, ahmed.ismail@damanhour.edu.eg.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ismail
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Seo
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Takebayashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kamiya
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Eiche
authors.forename: Peter
authors.initials: P
authors.lastname: Nick
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D003517:Cyclopentanes / Q000494:pharmacology*; D005682:Gadolinium / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D054883:Oxylipins / Q000494:pharmacology*; D055049:Salt Tolerance / Q000187:drug effects / Q000502:physiology*; D012964:Sodium / Q000378:metabolism; D013267:Stilbenes / Q000378:metabolism
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D013267:Stilbenes; C011006:jasmonic acid; D000040:Abscisic Acid; D012964:Sodium; D005682:Gadolinium; D002118:Calcium