Natural genetic variation in calcium sensor genes as a novel resource for abiotic stress tolerance in crops

Abiotic stress represents a significant and increasing challenge to global crop productivity and food security. Calcium (Ca²⁺) signaling, initiated by specific "Ca²⁺ signatures" and interpreted by sensor proteins such as calcium-dependent protein kinases (CDPKs/CPKs) and the CBL-CIPK network, functions as a key regulator of plant adaptive responses. However, contemporary elite cultivars exhibit a reduced genetic base, having forfeited numerous resilient alleles present in wild relatives and landraces during intensive, yield-focused breeding. This review synthesizes evidence demonstrating that natural genetic variation within these calcium sensor genes significantly influences key agronomic traits, including ion homeostasis, stomatal regulation, and water-use efficiency. We then evaluate​ the effectiveness of integrated genomic approaches, such as pan-genomics, genome-wide association studies (GWAS), and CRISPR-Cas9 genome editing, for systematically identifying and validating these beneficial alleles. Finally, we propose a translational roadmap for the targeted introgression of enhanced calcium sensor variants into modern germplasm. This work provides a strategic framework for developing a new generation of climate-resilient crops, offering a pathway to safeguard global food systems against increasingly erratic environmental conditions.