However, the members of this regulatory network vary with the DREB gene and/or with the type of stress [4] and [8]. Transgenic

crops overexpressing the DREB gene show significantly increased tolerance to stress under laboratory or greenhouse conditions. However, it remains undetermined whether these transgenic plants show enhanced stress tolerance under complex field conditions. In certain transgenic plants, the overexpression of the DREB gene under a constitutive CaMV35S promoter enhanced stress tolerance. However, simultaneously, negative effects on the plant phenotype were observed in these transgenic plants [16], [17] and [18]. For example, the constitutive expression of SbDREB2 led to pleiotropic Bcl-xL protein effects in rice, and these transgenic plants signaling pathway did not set seed [19]. Certain transgenic plants constitutively overexpressing the DREB gene showed better growth parameters than the wild type without growth retardation [20] and [21]. Thus the stress tolerance of transgenic plants grown in the field, the physiological and biochemical mechanisms of improving salt tolerance in transgenic plants, and the regulatory network of DREB genes require further study. The GmDREB1 gene (GenBank accession number AF514908), which encodes

a stress-inducible transcription factor, was cloned by screening a cDNA library of Glycine max cv. Jinong 27 using the yeast one-hybrid method [22]. The stress-inducible expression of GmDREB1 conferred salt tolerance on transgenic alfalfa plants [23]. T1 transgenic lines of wheat with Ubi::GmDREB1 and with rd29A::GmDREB1 showed better drought and salt tolerance than wild-type plants [22]. In the present study, the advanced-generation Ergoloid transgenic wheat lines T349 and T378 with Ubi::GmDREB1 and the wild-type Jimai 19 were used to evaluate the salt tolerance of these plants at the germination and seedling stages and throughout the growing season. Using a

comparative proteomic approach, we investigated the mechanisms that underlie high-salinity tolerance in Ubi::GmDREB1 transgenic wheat based on phenotypic characteristics, physiological parameters and protein responses to salt stress. T349 and T378 are transgenic lines of wheat constitutively expressing the GmDREB1 gene under the control of the maize ubiquitin promoter in wheat variety Jimai 19. Wild-type Jimai 19 was used as the control. In total, 100 seeds of each genotype were germinated on wet filter paper in culture dishes with distilled water (CK) and with a 2.0% NaCl solution under white light (150 μmol Photons m− 2 s− 1; 14-h light/10-h dark photoperiod) at 20 °C in a growth chamber. When the coleoptiles were 1/3 or the radicle was 1/2 of the length of the seed, the seed was considered germinated. The percent germination under CK and the treatment was scored at 5 and 10 days, respectively, after seeding.