A tomato bZIP transcription factor, SlAREB, is involved in water deficit and salt stress response.
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.
Hsieh
Tsai-Hung
TH
Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan.
Li
Chia-Wen
CW
Su
Ruey-Chih
RC
Cheng
Chiu-Ping
CP
Sanjaya
Tsai
Yi-Chien
YC
Chan
Ming-Tsair
MT
D000040:Abscisic Acid / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics; D029681:Arabidopsis Proteins / Q000378:metabolism; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018744:DNA, Plant / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017930:Genes, Reporter / Q000235:genetics; D008156:Luciferases / Q000378:metabolism; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D011523:Protoplasts / Q000378:metabolism; D020218:Response Elements / Q000235:genetics; D054712:Salinity; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects*; D015533:Transcriptional Activation / Q000187:drug effects / Q000235:genetics; D019076:Transgenes / Q000235:genetics; D014867:Water / Q000378:metabolism*
D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D018744:DNA, Plant; D010940:Plant Proteins; C520629:RD29a protein, Arabidopsis; D014867:Water; C070556:dehydrin proteins, plant; D012965:Sodium Chloride; D000040:Abscisic Acid; D008156:Luciferases