title: The short-term growth response to salt of the developing barley leaf.
abstract: Recent results concerning the short-term growth response to salinity of the developing barley leaf are reviewed. Plants were grown hydroponically and the growth response of leaf 3 was studied between 10 min and 5 d following addition of 100 mM NaCl to the root medium. The aim of the experiments was to relate changes in variables that are likely to affect cell elongation to changes in leaf growth. Changes in hormone content (ABA, cytokinins), water and solute relationships (osmolality, turgor, water potential, solute concentrations), gene expression (water channel), cuticle deposition, membrane potential, and transpiration were followed, while leaf elongation velocity was monitored. Leaf elongation decreased close to zero within seconds following addition of NaCl. Between 20 and 30 min after exposure to salt, elongation velocity recovered rather abruptly, to about 46% of the pre-stress level, and remained at the reduced rate for the following 5 d, when it reached about 70% of the level in non-stressed plants. Biophysical and physiological analyses led to three major conclusions. (i) The immediate reduction and sudden recovery in elongation velocity is due to changes in the water potential gradient between leaf xylem and peripheral elongating cells. Changes in transpiration, ABA and cytokinin content, water channel expression, and plasma membrane potential are involved in this response. (ii) Significant solute accumulation, which aids growth recovery, is detectable from 1 h onwards; growing and non-growing leaf regions and mesophyll and epidermis differ in their solute response. (iii) Cuticular wax density is not affected by short-term exposure to salt; transpirational changes are due to stomatal control.
authors.affiliation: Division of Biological Sciences, University of Paisley, Paisley PA1 2BE, UK. wieland02fricke@yahoo.co.uk
authors.forename: Wieland
authors.initials: W
authors.lastname: Fricke
authors.forename: Gulya
authors.initials: G
authors.lastname: Akhiyarova
authors.forename: Wenxue
authors.initials: W
authors.lastname: Wei
authors.forename: Erik
authors.initials: E
authors.lastname: Alexandersson
authors.forename: Anthony
authors.initials: A
authors.lastname: Miller
authors.forename: Per Ola
authors.initials: PO
authors.lastname: Kjellbom
authors.forename: Andrew
authors.initials: A
authors.lastname: Richardson
authors.forename: Tobias
authors.initials: T
authors.lastname: Wojciechowski
authors.forename: Lukas
authors.initials: L
authors.lastname: Schreiber
authors.forename: Dima
authors.initials: D
authors.lastname: Veselov
authors.forename: Guzel
authors.initials: G
authors.lastname: Kudoyarova
authors.forename: Vadim
authors.initials: V
authors.lastname: Volkov
mesh_terms: D000040:Abscisic Acid / Q000502:physiology; D020346:Aquaporins / Q000378:metabolism; D002713:Chlorine / Q000378:metabolism; D003583:Cytokinins / Q000502:physiology; D001467:Hordeum / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D008564:Membrane Potentials; D008954:Models, Biological; D009994:Osmolar Concentration; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D018526:Plant Transpiration / Q000502:physiology; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D014867:Water / Q000378:metabolism
chemical_list: D020346:Aquaporins; D003583:Cytokinins; D014867:Water; D012965:Sodium Chloride; D002713:Chlorine; D000040:Abscisic Acid; D012964:Sodium; D011188:Potassium