Table_6_Genome-wide identification and expression analysis of the U-box E3 ubiquitin ligase gene family related to salt tolerance in sorghum (Sorghum bicolor L.).docx

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 (Sorghum bicolor L.). In the present study, 59 SbPUB genes were identified in the sorghum genome. Based on the phylogenetic analysis, the 59 SbPUB genes were clustered into five groups, which were also supported by the conserved motifs and structures of these genes. SbPUB genes were found to be unevenly distributed on the 10 chromosomes of sorghum. Most PUB genes (16) were found on chromosome 4, but there were no PUB genes on chromosome 5. Analysis of cis-acting elements showed that SbPUB genes were involved in many important biological processes, particularly in response to salt stress. From proteomic and transcriptomic data, we found that several SbPUB genes had diverse expressions under different salt treatments. To verify the expression of SbPUBs, qRT-PCR analyses also were conducted under salt stress, and the result was consistent with the expression analysis. Furthermore, 12 SbPUB 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 PUB 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.

植物U-box（PUB）泛素连接酶在多种生物学过程和应激反应中发挥着至关重要的角色，然而关于其在高粱（高粱属二色高粱L.）中的功能，了解甚少。在本研究中，我们已在高粱基因组中鉴定出59个SbPUB基因。基于系统发育分析，这59个SbPUB基因被聚类为五个组别，这一结果也得到了这些基因保守基序和结构的支持。研究发现，SbPUB基因在高粱的10条染色体上的分布并不均匀。大多数PUB基因（16个）位于第4染色体上，而第5染色体上则没有PUB基因。对顺式作用元件的分析表明，SbPUB基因参与了众多重要的生物学过程，特别是在对盐胁迫的响应中。从蛋白质组学和转录组学数据中，我们发现几个SbPUB基因在不同盐处理条件下表现出多样化的表达。为了验证SbPUBs的表达，我们在盐胁迫条件下进行了qRT-PCR分析，结果与表达分析一致。此外，我们还发现12个SbPUB基因含有MYB相关元件，这些元件是类黄酮生物合成的重要调节因子。这些结果与我们对高粱盐胁迫的多组学分析结果一致，为高粱耐盐机理的深入研究奠定了坚实基础。本研究表明，PUB基因在调节盐胁迫中发挥着关键作用，未来有望成为培育耐盐高粱的潜在靶标。