The proposed innovation relates to the biotechnological improvement of plant species of commercial interest. More specifically, the present invention relates to the production of transgenic plants biotechnological with greater tolerance to water deficit and salt stress by means of the expression of a new gene of coffee (of the Coffea Arabica species), belonging to the HD-Zip family, and characterized by a homeodomain associated with a leucine zipper. The expression of this transcriptional factor is induced in leaves and roots of coffee plants subjected to various water deficit conditions (both moderate and severe); transgenic plants that over-express this gene inhibiting greater tolerance both to differ drought intensities and to high salt concentrations.