Role of soybean GmbZIP132 under abscisic acid and salt stresses

Plant basic-leucine zipper (bZIP) transcription factors play important roles in many biological processes. In the present study, a bZIP gene, GmbZIP132, was cloned from soybean and its biological function under abiotic stresses was studied. The transcription of GmbZIP132 was induced by drought and high salt treatments. Among all of the organs analyzed, its expression was the highest in cotytledon and stems. GmbZIP132 could weakly bind to the GCN4-like motif (GLM) (5'-GTGAGTCAT-3') in yeast one-hybrid assay. Compared with wild-type (WT) Arabidopsis plants, transgenic plants overexpressing GmbZIP132 showed reduced abscisic acid sensitivity and increased water loss rate. At the stage of germination, transgenic plants were more tolerant to salt treatment than wild-type plants. The expression of some abiotic stress-related genes, such as rd29B, DREB2A, and P5CS, were upregulated in the transgenic plants. These results indicated that GmbZIP132 was an abiotic stress-related gene, and its overexpression could increase the salt tolerance of transgenic Arabidopsis plants during germination, yet no significant difference of tolerance to abiotic stresses was found between transgenic and wild type plants at the seedling stage.