title: Overexpression of SlSOS2 (SlCIPK24) confers salt tolerance to transgenic tomato.
abstract: The Ca(2+)-dependent SOS pathway has emerged as a key mechanism in the homeostasis of Na(+) and K(+) under saline conditions. We have identified and functionally characterized the gene encoding the calcineurin-interacting protein kinase of the SOS pathway in tomato, SlSOS2. On the basis of protein sequence similarity and complementation studies in yeast and Arabidopsis, it can be concluded that SlSOS2 is the functional tomato homolog of Arabidopsis AtSOS2 and that SlSOS2 operates in a tomato SOS signal transduction pathway. The biotechnological potential of SlSOS2 to provide salt tolerance was evaluated by gene overexpression in tomato (Solanum lycopersicum L. cv. MicroTom). The better salt tolerance of transgenic plants relative to non-transformed tomato was shown by their faster relative growth rate, earlier flowering and higher fruit production when grown with NaCl. The increased salinity tolerance of SlSOS2-overexpressing plants was associated with higher sodium content in stems and leaves and with the induction and up-regulation of the plasma membrane Na(+)/H(+) (SlSOS1) and endosomal-vacuolar K(+), Na(+)/H(+) (LeNHX2 and LeNHX4) antiporters, responsible for Na(+) extrusion out of the root, active loading of Na(+) into the xylem, and Na(+) and K(+) compartmentalization.
authors.affiliation: Department of Biochemistry, Molecular and Cellular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), C/ Prof. Albareda 1, E-18008 Granada, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: Huertas
authors.forename: Raquel
authors.initials: R
authors.lastname: Olías
authors.forename: Zakia
authors.initials: Z
authors.lastname: Eljakaoui
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Gálvez
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Paz Alvarez
authors.initials: PA
authors.lastname: De Morales
authors.forename: Andrés
authors.initials: A
authors.lastname: Belver
authors.forename: María Pilar
authors.initials: MP
authors.lastname: Rodríguez-Rosales
mesh_terms: D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000235:genetics; D005816:Genetic Complementation Test; D018551:Solanum lycopersicum / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012492:Salts
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D012492:Salts