Genome-wide identification of bZIP transcription factors in 12 Rosaceae species and modeling of novel mechanisms of EjbZIPs response to salt stress

In plantae, basic leucine zipper (bZIP) transcription factors (TFs) are widespread and regulate a variety of biological processes under abiotic stress. However, it has not been extensively studied in Rosaceae, and the functional effects of bZIP on Eriobotrya japonica under salt stress are still unknown. Therefore, in this study, the bZIP TF family of 12 species of Rosaceae was analyzed by bioinformatics method, and the expression profile and quantitative real-time polymerase chain reaction of E. japonica under salt stress were analyzed. The results showed that a total of 869 bZIP TFs were identified in 12 species of Rosaceae and divided into nine subfamilies. Differences in promoter cis-elements between subfamilies vary depending on their role. Species belonging to the same subfamily have a similar number of chromosomes and the number of genes contained on each chromosome. Gene duplication analysis has found segmental duplication to be a prime force in the evolution of Rosaceae species. In addition, nine EjbZIPs were significantly different, including seven up-regulated and two down-regulated in E. japonica under salt stress. Especially, EjbZIP13 was involved in the expression of SA-responsive proteins by binding to the NPR1 gene. EjbZIP27, EjbZIP30, and EjbZIP38 were highly expressed in E. japonica under salt stress, thus improving the salt tolerance capacity of the plants. These results can provide a theoretical basis for exploring the characteristics and functions of the bZIP TF family in more species and breeding salt-tolerant E. japonica varieties. It also provides a reference for resolving the response mechanism of bZIP TF in 12 Rosaceae species under salt stress. Plain Language Summary Basic leucine zipper (bZIP) transcription factors exist widely in the plant kingdom and regulate a variety of biological processes under abiotic stress. Rosaceae plants have important economic value. Therefore, in this study, bZIP of 12 species of Rosaceae was analyzed by bioinformatics method, and the expression profile and quantitative real-time polymerase chain reaction of loquat under salt stress were analyzed. A total of 869 bZIP transcription factors were identified from 12 Rosaceae species. Under salt stress, nine loquat samples were significantly expressed; seven were up-regulated and two were down-regulated. In particular,EjbZIP13,EjbZIP27,EjbZIP30,andEjbZIP38were highly expressed in loquat seedlings under salt stress, thus improving the salt tolerance of the plants. These results can provide a theoretical basis for exploring the characteristics and functions of the bZIP TF family in more species and breeding salt-tolerant Eriobotrya japonica varieties.