A tomato bZIP transcription factor, SlAREB, is involved in water deficit and salt stress response

Abstract

Abiotic stresses such as cold, water deficit, and salt stresses severely reduce crop productivity. Tomato (Solanum lycopersicum) is an important economic crop; however, not much is known about its stress responses. To gain insight into stress-responsive gene regulation in tomato plants, we identified transcription factors from a tomato cDNA microarray. An ABA-responsive element binding protein (AREB) was identified and named SlAREB. In tomato protoplasts, SlAREB transiently transactivated luciferase reporter gene expression driven by AtRD29A (responsive to dehydration) and SlLAP (leucine aminopeptidase) promoters with exogenous ABA application, which was suppressed by the kinase inhibitor staurosporine, indicating that an ABA-dependent post-translational modification is required for the transactivation ability of SlAREB protein. Electrophoretic mobility shift assays showed that the recombinant DNA-binding domain of SlAREB protein is able to bind AtRD29A and SlLAP promoter regions. Constitutively expressed SlAREB increased tolerance to water deficit and high salinity stresses in both Arabidopsis and tomato plants, which maintained PSII and membrane integrities as well as water content in plant bodies. Overproduction of SlAREB in Arabidopsis thaliana and tomato plants regulated stress-related genes AtRD29A, AtCOR47, and SlCI7-like dehydrin under ABA and abiotic stress treatments. Taken together, these results show that SlAREB functions to regulate some stress-responsive genes and that its overproduction improves plant tolerance to water deficit and salt stress.

Tomato (Solanum lycopersicum L.) in the service of biotechnology

“…These results suggested that this class of bZIPs plays a role in abiotic stress response in the Solanum genus. In another study, Hsieh et al (2010) observed that the overexpression of SlAREB is responsible for increasing tolerance to water and salinity in tomato plants. The sverproduction of SlAREB in transgenic tomato plants regulated genes AtRD29A, AtCOR47, and SlCI-like dehydrin under ABA and abiotic stress treatments.…”

Salt Stress in Higher Plants: Mechanisms of Toxicity and Defensive Responses

“…In addition, the homozygous T-DNA insertional mutants Osabf-1 and Osabf-2 were more sensitive to drought and salt stress than WT plants (Hossain et al 2010). Constitutive expression of the AREB ortholog TF from tomato (Solanum lycopersicum), SlAREB, increased tolerance to water deficit and high salinity in Arabidopsis and tomato plants, maintaining photosystem II and membrane integrities, and water content (Hsieh et al 2010).…”

Genomic identification of group A bZIP transcription factors and their responses to abiotic stress in carrot

“…A number of studies have evaluated the function of group A TFs in rice, their results demonstrating that the overexpression of OsABI5 lead to a higher sensitivity to salt stress (Zou et al, 2008), and that of OsABF1 and OsABF2 enhanced the abiotic stress signaling (Hossain et al, 2010a,b). In Arabidopsis, the roles of AREB1 and AREB2 in response to ABA, drought, and high salt stresses have been well-examined (Hsieh et al, 2010). Although several reports on bZIP family TFs in Arabidopsis and rice are available, similar studies in carrot are lacking.…”