TdSHN1, a WIN1/SHN1-type transcription factor, imparts multiple abiotic stress tolerance in transgenic tobacco

Abstract

The APETAL/Ethylene Responsive factor (AP2/ERF) is a large family of transcription factors (TFs) involved in the control of developmental programs and responses to environmental stimuli. The plasticity and specificity of its individual members make them valuable tools for both genetic engineering and breeding purposes. Here, we report the functional analysis of an AP2/ERF member, TdSHN1, from durum wheat. The ectopic expression of TdSHN1 under the control of the duplicated 35S promoter in transgenic tobacco plants leads to increased tolerance to salt, cold and water stresses compared to wild-type (WT) plants as demonstrated by physiological parameters such as lipoperoxidation, electrolyte leakage (EL), superoxide dismutase (SOD) and catalase (CAT) activity. The overexpression of TdSHN1 enhanced the expression of genes encoding oxidative stress-related proteins, osmotic stress proteins, lipid transfer proteins (LTPs), defense proteins and the wax biosynthesis gene NtCER1. Interestingly, the overexpression of TdSHN1 also leads to a significant reduction in stomatal density. Taken together, our results suggest that TdSHN1 TF may confer multiple abiotic stress tolerance not only through up-regulating of genes involved in response to oxidative and osmotic stress, but also by reducing stomatal density. Therefore, TdSHN1 may be a good candidate for engineering stress-tolerant plants.