The past two decades revealed a plethora of Ca2+-responsive proteins and downstream targets in plants, of which several are unique to plants. More recent high-throughput 'omics' approaches and bioinformatics are exposing Ca2+-responsive cis-elements and the corresponding Ca2+-responsive genes. Here, we review the current knowledge on Ca2+-signaling pathways that regulate gene expression in plants, and we link these to mechanisms by which plants respond to biotic and abiotic stresses.