In response to environmental stimuli, plants rapidly activate calcium signaling to initiate downstream responses. The transmission of calcium signals involves three primary processes: perception, decoding, and relay. Calcium-dependent protein kinases (CDPKs/CPKs), as key Ca ²⁺ sensors, not only detect calcium signals but also respond to them by translating these signals into physiological activities within the cell. The influx of calcium ions (Ca ²⁺ ) induced by pathogens triggers the conformational activation of cytosolic CPKs, which in turn enables the regulation of reactive oxygen species (ROS) production, MAPK cascades, transcriptional reprogramming, and hormone signaling. Acting as pivotal hubs in signal transduction, CPKs integrate diverse pathways to fine-tune the balance between growth and defense. We synthesize recent advances in understanding CPK-mediated immune mechanisms and their molecular crosstalk with other signaling networks. By highlighting emerging discoveries and unresolved questions, we provide a conceptual framework for exploiting CPKs to enhance durable and broad-spectrum disease resistance in crops.

The MYB transcription factor family, one of the largest in plants, plays a crucial role in responding to abiotic stress responses. Daylily ( Hemerocallis fulva L.) is a salt-tolerant plant ideal for coastal landscaping. In this study, we identified 33 MYB transcription factors from the ‘Autumn Red’ daylily roots under seawater stress, a discovery reported here for the first time. Chromosome mapping revealed an uneven distribution of these genes, with numerous segmental and tandem repeats. Phylogenetic analysis with Arabidopsis and rice MYBs classified the daylily MYBs into six subfamilies, which were further divided into five subclasses based on conserved domains. Expression profiling across different seawater treatment periods revealed distinct H, L, and M expression patterns. Through an integrated analysis of phylogeny, motif structure, and expression profiles, we identified HfMYB10 as a key candidate. Heterologous expression of HfMYB10 in Arabidopsis yielded homozygous transgenic linesexhibiting significantly enhanced seawater tolerance. Our findings clarify the role of daylily MYB transcription factors in seawater tolerance and offer valuable insights for breeding salt-resistant varieties.