摘要：Calcium (Ca2+), a crucial second messenger in plants, is involved in diverse signaling pathways including biotic and abiotic stress responses. However, the functions of most calcium sensors including calcium-dependent protein kinases (CDPKs), calmodulins (CaMs), calmodulin-like proteins (CMLs), and calcineurin B-like proteins (CBLs) remain limited in plants, particularly in woody plants. Currently, a total of 83CMLsand sevenCaMswere discovered in the apple genome in this study. Functional domain analysis showed that these CMLs and CaMs contain a highly conserved EF-hand motif. qRT-PCR assays indicated that theseCMLswere expressed ubiquitously in apple, including in the roots, stems, leaves, flowers, and fruits, and also possessed spatial specificity. Finally, most of theseCMLswere induced by hormonal and abiotic stress, suggesting their potential roles in the regulation of growth, development, and the stress response in apple. In summary, our findings provide potential evidence that appleCMLsmay be involved in abiotic stress and the regulation of plant growth and development.
