Genome-wide identification and expression analysis of the U-box E3 ubiquitin ligase gene family related to salt tolerance in sorghum ( L.).

Plant U-box (PUB) E3 ubiquitin ligases play essential roles in many biological processes and stress responses, but little is known about their functions in sorghum ( L.). In the present study, 59 genes were identified in the sorghum genome. Based on the phylogenetic analysis, the 59 genes were clustered into five groups, which were also supported by the conserved motifs and structures of these genes. genes were found to be unevenly distributed on the 10 chromosomes of sorghum. Most genes (16) were found on chromosome 4, but there were no genes on chromosome 5. Analysis of -acting elements showed that genes were involved in many important biological processes, particularly in response to salt stress. From proteomic and transcriptomic data, we found that several genes had diverse expressions under different salt treatments. To verify the expression of , qRT-PCR analyses also were conducted under salt stress, and the result was consistent with the expression analysis. Furthermore, 12 genes were found to contain MYB-related elements, which are important regulators of flavonoid biosynthesis. These results, which were consistent with our previous multi-omics analysis of sorghum salt stress, laid a solid foundation for further mechanistic study of salt tolerance in sorghum. Our study showed that genes play a crucial role in regulating salt stress, and might serve as promising targets for the breeding of salt-tolerant sorghum in the future.