Transcription factors in plants and ABA dependent and independent abiotic stress signalling

Plants face variable environmental stresses that negatively affect plant growth and productivity. The multiplicity of responses is an important aspect of the complexity of stress signalling. Abscisic acid (ABA) is a broad-spectrum phytohormone involved not only in regulating stomatal opening, growth and development but also in coordinating various stress signal transduction pathways in plants during abiotic stresses. The both ABA-dependent and ABA-independent signal transduction pathways from stress signal perception to gene expression involve different transcription factors such as DREB, MYC/MYB, AREB/ABF, NAM, ATAF1,2, CUC and their corresponding cis-acting elements DRE, MYCRS/MYBRS, ABRE, NACRS. Genetic analysis of ABA mutants has given insight that ABA-dependent and ABA-independent pathways for osmotic stress and cold stress interact and converge. This review focuses on ABA-dependent and ABA-independent transcriptional components and cascades, their specificity and crosstalk in stress gene regulation.