The Translation Initiation Factor 1A () from Is Regulated by a Dof Transcription Factor and Increased Abiotic Stress Tolerance.

Eukaryotic translation initiation factor 1A () functions as an mRNA scanner and AUG initiation codon locator. However, few studies have clarified the role of in abiotic stress. In this study, we cloned () from and found its expression to be induced by NaCl and polyethylene glycol (PEG) in roots, stems, and leaves. Compared to control, root expression was increased 187.63-fold when exposed to NaCl for 6 h, suggesting a potential abiotic stress response for this gene. Furthermore, transgenic tobacco plants overexpressing exhibited enhanced seed germination and a higher total chlorophyll content under salt and mannitol stresses. Increased superoxide dismutase, peroxidase, glutathione transferase and glutathione peroxidase activities, as well as decreased electrolyte leakage rates and malondialdehyde contents, were observed in -transgenic tobacco and seedlings under salt and mannitol stresses. Histochemical staining suggested that improves reactive oxygen species (ROS) scavenging in plants. Moreover, may regulate expression of stress-related genes, including , , , , , and . Moreover, a 1352-bp promoter fragment of was isolated, and -elements were identified. Yeast one-hybrid assays showed that ThDof can specifically bind to the Dof motif present in the promoter. In addition, showed expression patterns similar to those of under NaCl and PEG stresses. These findings suggest the potential mechanism and physiological roles of . may be an upstream regulator of , and may function as a stress response regulator to improve plant salt and osmotic stress tolerance via regulation of associated enzymes and ROS scavenging, thereby reducing cell damage under stress conditions.