The Peach (Prunus persica) CBL and CIPK Family Genes: Protein Interaction Profiling and Expression Analysis in Response to Various Abiotic Stresses

The plant calcineurin B-like protein–CBL interacting protein kinase (CBL–CIPK) signaling pathway is a Ca2+-related signaling pathway that responds strongly to both biological and abiotic environmental stimuli. This study identified eight CBL and eighteen CIPK genes from peach for the first time. Their basic properties and gene structure were analyzed, and the CBL and CIPK members from Arabidopsis and apple were combined to study their evolutionary relationships. Using RT-qPCR and RNA-seq data, we detected the expression patterns of PprCBLs and PprCIPKs in different tissues and fruit development stages of peach. Among them, the expression levels of PprCBL1 and PprCIPK18 were stable in various tissues and stages. The expression patterns of other members showed specificity between cultivars and developmental stages. By treating shoots with drought and salt stress simulated using PEG6000 and NaCl, it was found that PprCIPK3, PprCIPK6, PprCIPK15 and PprCIPK16 were strongly responsive to salt stress, and PprCIPK3, PprCIPK4, PprCIPK10, PprCIPK14, PprCIPK15, PprCIPK16 and PprCIPK18 were sensitive to drought stress. Three genes, PprCIPK3, PprCIPK15 and PprCIPK16, were sensitive to both salt and drought stress. We cloned four PprCBL and several PprCIPK genes and detected their interaction by yeast two-hybrid assay (Y2H). The results of Y2H show not only the evolutionary conservation of the interaction network of CBL–CIPK but also the specificity among different species. In conclusion, CBL and CIPK genes are important in peach and play an important role in the response to various abiotic stresses.