The MYB transcription factor family can regulate biological processes such as ABA signal transduction to cope with drought stress, but its evolutionary mechanism and the diverse pathways of response to drought stress in different species are rarely reported. In this study, a total of 4791 MYB family members were identified in 908,757 amino acid sequences from 12 model plants or crops using bioinformatics methods. It was observed that the number of MYB family members had a linear relationship with the chromosome ploidy of species. A phylogenetic analysis showed that the MYB family members evolved in subfamily clusters. In response to drought stress, the pathways of MYB transcription factor families exhibited species-specific diversity, with closely related species demonstrating a higher resemblance. This study provides abundant references for drought resistance research and the breeding of wheat, soybean, and other plants.

Freezing temperatures severely restrict plant growth and can cause serious damage or death to sugar beet seedlings in early spring. In this study, seedlings of two sugar beet genotypes, KWS1197 (K, freezing-tolerant) and SX1512 (S, freezing-sensitive), were subjected to RNA sequencing (RNA-seq) after exposure to −4 °C for 0, 1, 3, and 5 h. GO and KEGG enrichment and expression pattern analyses were performed to identify differentially expressed genes (DEGs) associated with freezing stress. The results showed that plant hormone signal transduction and the MAPK signaling pathway were the primary pathways involved in the freezing response in both genotypes. Notably, the galactose metabolism pathway may play an important role in freezing tolerance in KWS1197. Genes involved in galactose metabolism, including inositol 3-α-galactosyltransferase (GolS), raffinose synthase (RafS), invertase (INV), and α-galactosidase (GLA), were significantly up-regulated under freezing conditions, as confirmed by both RNA-seq and RT-qPCR analyses. These results suggest that rapid regulation of soluble sugar synthesis may represent an important mechanism contributing to freezing tolerance in sugar beet. Overall, this study provides a molecular basis for understanding freezing tolerance in sugar beet and identifies candidate genes for improving freezing resistance.

Sugar beet cytoplasmic male sterility (CMS) underpins hybrid seed production, yet the contribution of protein phosphorylation remains unexplored. Using 4D label-free phosphoproteomics on anthers of the Owen-type CMS line MS327 and its maintainer OT328 at the 2–3 mm bud stage, we identified 1241 phosphoproteins, 1975 phosphopeptides and 3357 phosphosites, of which 469 proteins and 848 sites were quantifiable. Twenty-one phosphopeptides exhibited significant differential abundance (fold change > 2.0, p < 0.05; 3 up, 18 down), while 69 and 141 peptides were detected exclusively in the maintainer and the sterile line, respectively. Pathway enrichment implicated the spliceosome and fatty acid elongation pathways in male sterility. Integrating KEGG, GO and predicted protein–protein interaction networks analyses, we identified nuclear cap-binding protein subunit 2 (NCBP2), the RRM-containing splicing factor SR45a and 3-ketoacyl-CoA synthase as candidate phosphoproteins associated with male sterility. All six core proteins were deeply conserved across the examined species. Although transcript levels of the six corresponding genes did not differ significantly between the two lines in either leaf or anthers, anther phosphorylation levels did, pointing to post-translational rather than transcriptional control. This first phosphoproteomic survey of sugar beet CMS provides a valuable readout of post-translational reprogramming and offers promising candidate targets for future functional validation.