title: Effect of salt stress on ion concentration, proline content, antioxidant enzyme activities and gene expression in tomato cultivars.
abstract: Salinity is a constraint limiting plant growth and productivity of crops throughout the world. Understanding the mechanism underlying plant response to salinity provides new insights into the improvement of salt tolerance-crops of importance. In the present study, we report on the responses of twenty cultivars of tomato. We have clustered genotypes into scale classes according to their response to increased NaCl levels. Three local tomato genotypes, representative of different saline scale classes, were selected for further investigation. During early (0 h, 6 h and 12 h) and later (7 days) stages of the response to salt treatment, ion concentrations (Na+, K+and Ca2+), proline content, enzyme activities (catalase, ascorbate peroxidase and guiacol peroxidase) were recorded. qPCR analysis of candidate genes WRKY (8, 31and 39), ERF (9, 16 and 80), LeNHX (1, 3 and 4) and HKT (class I) were performed. A high K+, Ca2 +and proline accumulation as well as a decrease of Na+concentration-mediated salt tolerance. Concomitant with a pattern of high-antioxidant enzyme activities, tolerant genotypes also displayed differential patterns of gene expression during the response to salt stress.
authors.affiliation: Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis ElManar, Tunis 2092, Tunisia.
authors.forename: Charfeddine
authors.initials: C
authors.lastname: Gharsallah
authors.affiliation: Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis ElManar, Tunis 2092, Tunisia Faculty of Sciences of Bizerte, University of Carthage, Zarzouna 7021, Tunisia.
authors.forename: Hatem
authors.initials: H
authors.lastname: Fakhfakh
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Weinberg 3, Halle, 06120 Saale, Germany.
authors.forename: Douglas
authors.initials: D
authors.lastname: Grubb
authors.affiliation: Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis ElManar, Tunis 2092, Tunisia Faculty of Sciences of Bizerte, University of Carthage, Zarzouna 7021, Tunisia fatengorsane@gmail.com faten.gorsne@fss.rnu.tn.
authors.forename: Faten
authors.initials: F
authors.lastname: Gorsane
keywords: Antioxidant enzymes; Tunisian tomato genotypes; gene expression; ion contents; qPCR; salt stress