Coping with Drought and Salinity Stresses: Role of Transcription Factors in Crop Improvement

Abstract

The knowledge about the role of transcription factors in the eukaryotic domain, mainly in yeast, Drosophila, human, and later in plants, significantly advanced since the first discovery of these regulatory proteins in prokaryotes, fifty years ago. Transcription factors are involved in a variety of biological processes including the responses to environmental changes. In this review, we focus on plant transcription factors involved in the responses to abiotic stresses, mainly drought and salinity. We analyze the modular structure that characterizes common and kingdom-specific groups or families and the main environmental stimuli that modulate the responses through different signaling pathways. Thereafter, we review examples of the roles played by transcription factors in classical breeding approaches for crop improvement. Finally, we revise the discovery, characterization and use of transcription factors as biotechnological tools. About the last point, we discuss the experimental methods and parameters adopted to evaluate tolerant phenotypes and the apparent dilemma between crops yield and stress tolerance.