Genome-wide identification and salt stress response analysis of the SnRK2 gene family in blueberry

The SnRK2 gene family is a plant-specific serine/threonine protein kinase family. To clarify the expression pattern of the blueberry SnRK2 gene family under salt stress and explore the key SnRK2 genes involved in blueberry salt stress response, bioinformatics methods were used to identify members of the SnRK2 family at the whole-genome level. Their expression patterns under salt stress were analyzed using transcriptome data and real-time quantitative PCR (RT-qPCR) technology. The results showed that a total of 17 VcSnRK2 gene family members were identified, named VcSnRK2.1 to VcSnRK2.17, respectively. Subcellular localization prediction indicated that VcSnRK2 proteins were mainly localized in the cytoplasm and cytoskeleton. Phylogenetic tree analysis revealed that the VcSnRK2 gene family could be divided into three subgroups, and there were differences in gene structure and conserved motifs among different subgroups. The members of this family were distributed on 14 scaffolds, and the promoter regions were rich in various types of cis-acting elements, such as those responding to hormones and abiotic stresses. Based on blueberry salt stress transcriptome data, a total of 6 differentially expressed genes were screened out. Combined with RT-qPCR experiments, it was found that VcSnRK2.1, VcSnRK2.13 and VcSnRK2.14 were mainly differentially expressed in blueberry roots, while VcSnRK2.6 and VcSnRK2.15 were mainly differentially expressed in leaves, indicating that they might be involved in blueberry salt stress response.