Delineating Calcium Signaling Machinery in Plants: Tapping the Potential through Functional Genomics

: Plant systems have developed calcium (Ca2+) signaling as an important mechanism of regulation of stress perception, developmental cues, and responsive gene expression. The post-genomic era has witnessed the successful unravelling of the functional characterization of genes and the creation of large datasets of molecular information. The major elements of Ca2+ signaling machinery involve Ca2+ sensors and responders such as Calmodulin (CaM), Calmodulin-like proteins (CMLs), Ca2+/CaM-dependent protein kinases (CCaMK), Ca2+-dependent protein kinases (CDPKs), Calcineurin B-like proteins (CBLs) as well as transporters, such as Cyclic nucleotide-gated channels (CNGCs), Glutamate-like receptors (GLRs), Ca2+-ATPases, Ca2+/H+ exchangers (CAXs) and mechanosensitive channels. These elements play an important role in the regulation of physiological processes and plant responses to various stresses. Detailed genomic analysis can help us in the identification of potential molecular targets that can be exploited towards the development of stress-tolerant crops. The information sourced from model systems through omics approaches helps in the prediction and simulation of regulatory networks involved in responses to different stimuli at the molecular and cellular levels. The molecular delineation of Ca2+ signaling pathways could be the stepping stone for engineering climate-resilient crop plants. Here, we review the recent developments in Ca2+ signaling in the context of transport, responses, and adaptations significant for crop improvement through functional genomics approaches.