Genome-Wide Identification and Abiotic Stress Expression Analysis of and Family Genes in Cucumber ( L.).

Cytokinins (CKs) are among the hormones that regulate plants' growth and development, and the and genes, which are CK degradation and biosynthesis genes, respectively, play important roles in fine-tuning plants' cytokinin levels. However, the current research on the function of and in cucumber's growth, development, and response to abiotic stress is not specific enough, and their regulatory mechanisms are still unclear. In this study, we focused on the and genes in cucumber, analyzed the physiological and biochemical properties of their encoded proteins, and explored their expression patterns in different tissue parts and under low light, salt stress, and drought stress. Eight and eight genes were identified from the cucumber genome. We constructed a phylogenetic tree from the amino acid sequences and performed prediction analyses of the cis-acting elements of the and promoters to determine whether and are responsive to light, abiotic stress, and different hormones. We also performed expression analysis of these genes in different tissues, and we found that and were highly expressed in roots and male flowers. Thus, they are involved in the whole growth and development process of the plant. This paper provides a reference for further research on the biological functions of and in regulating the growth and development of cucumber and its response to abiotic stress.