Identification and characterization of novel <i>SUMO</i> genes in bread wheat

The small-ubiquitin-like-modifier (SUMO), composed of approximately 100 amino acid residues, regulates the cellular activity of several proteins by posttranslational modification. Almost all plant species express a family of SUMO isoforms. Nevertheless, the <i>SUMO</i> genes in wheat (<i>TaSUMOs</i>) have not undergone complete characterization, and the roles of <i>TaSUMOs</i> remain unidentified. The study identified four new <i>SUMO</i> genes in wheat, named <i>TaSUMO4-7</i>, in addition to the previously known <i>TaSUMO1-3</i>. These genes are part of the conserved SUMO family, as indicated by phylogenetic analysis. The genes contain the characteristic SUMO-acceptor site motif and the essential C-terminal diglycine motif for processing. Expression analysis showed that <i>TaSUMO4-7</i> genes are expressed in various wheat tissues. Bioinformatics analysis predicted the biochemical properties and structures of the proteins, which were found to localize in the cytoplasm and nucleus. The study confirms that the new <i>TaSUMO4-7</i> genes are functional members of the wheat SUMO family and lays the groundwork for further research into their specific roles.