ERF protein JERF1 that transcriptionally modulates the expression of abscisic acid biosynthesis-related gene enhances the tolerance under salinity and cold in tobacco

Increasing evidences indicate that ethylene responsive factor (ERF) proteins regulate a variety of biotic and abiotic stress responses, and plant development as well. Previously we demonstrated that JERF1, encoding an ERF transcriptional activator, is inducible by ethylene, MeJA, ABA, and NaCl, suggesting its possible regulation in multiple stress responses. In the present paper, we report that expressing JERF1 in tobacco increases the seed germination under mannitol treatment, and enhances the tolerance to high salinity and low temperature, through accumulating sodium in vacuole of leaves and stabilizing the plasma membrane, respectively, and significantly increases the growth of tobacco roots and leaves under salinity and low temperature through an unknown mechanism. The evidence that JERF1 interacts with multiple cis-acting elements, such as GCC-box, DRE, and CE1, to activate the expression of stress-related genes, supports the possible involvement of JERF1 in multiple plant stress responses with ABA-dependent and ABA-independent manner. More importantly, we reveal that expressing JERF1 in tobacco transcriptionally regulates the expression of ABA biosynthesis-related gene NtSDR, resulting in the increase of the ABA content. Together, our results indicate that JERF1 interacts with multiple cis-acting elements and activates the expression of stress responsive and ABA biosynthesis-related genes, consequently causing ABA biosynthesis, and ultimately enhancing tobacco tolerance and growth under high salinity and low temperature.