A simplified working model of a signaling network of plant responses to abiotic stress. Ovals represent proteins, metabolites or processes. Metabolites have magenta color. Phosphorylated proteins have red circles with a P inside. Sumoylated protein has an orange circle with an S inside. The solid purple circle indicates that DREB2 needs modification to be activated. Solid lines represent direct connections; dotted lines represent indirect connections (acting through some intermediate molecule). The gray line indicates that this reaction has not been shown in plants. Not all linkages and details of stress and hormone effects are shown in this diagram in order to simplify the model. Abbreviations: ABA (abscisic acid), ANAC (Arabidopsis NAC domain-containing protein), CAMTA (calmodulin-binding transcription activator), CBL (calcineurin B-like interacting protein kinase), CCA (circadian clock associated), CPK (calcium-dependent protein kinase), DREB/CBF (dehydration response element binding protein/C-repeat binding factor), ETR1 (ethylene response 1), GCN2 (general control non-repressible 2), HSF (heat shock factor), ICE (inducer of CBF expression), MAPK (mitogen-activated protein kinase), LHY (late elongated hypocotyl), PA (phosphatidic acid), PP2C (protein phosphatase 2C), PRR (pseudo response regulator), PYR/PYL/RCAR (ABA receptors), RNS (reactive nitrogen species), ROS (reactive oxygen species), SIZ (SAP and Miz domain protein), SnRK (sucrose nonfermenting-1 related kinase), TFs (transcription factors), TOR (target of rapamycin), ZAT (zinc finger protein).