The ERF transcription factor Ta ERF 3 promotes tolerance to salt and drought stresses in wheat

Summary Salinity and drought are major limiting factors of wheat ( T riticum aestivum ) productivity worldwide. Here, we report the function of a wheat ERF transcription factor Ta ERF 3 in salt and drought responses and the underlying mechanism of Ta ERF 3 function. Upon treatment with 250 m m NaCl or 20% polyethylene glycol ( PEG ), transcript levels of Ta ERF 3 were rapidly induced in wheat. Using wheat cultivar Y angmai 12 as the transformation recipient, four Ta ERF 3‐ overexpressing transgenic lines were generated and functionally characterized. The seedlings of the Ta ERF 3‐ overexpressing transgenic lines exhibited significantly enhanced tolerance to both salt and drought stresses as compared to untransformed wheat. In the leaves of Ta ERF 3‐ overexpressing lines, accumulation levels of both proline and chlorophyll were significantly increased, whereas H 2 O 2 content and stomatal conductance were significantly reduced. Conversely, Ta ERF 3‐ silencing wheat plants that were generated through virus‐induced gene silencing method displayed more sensitivity to salt and drought stresses compared with the control plants. Real‐time quantitative RT‐PCR analyses showed that transcript levels of ten stress‐related genes were increased in Ta ERF 3 ‐overexpressing lines, but compromised in Ta ERF 3‐ silencing wheat plants. Electrophoretic mobility shift assays showed that the Ta ERF 3 protein could interact with the GCC ‐box cis ‐element present in the promoters of seven Ta ERF 3‐activated stress‐related genes. These results indicate that Ta ERF 3 positively regulates wheat adaptation responses to salt and drought stresses through the activation of stress‐related genes and that Ta ERF 3 is an attractive engineering target in applied efforts to improve abiotic stress tolerances in wheat and other cereals.