SWEET transporter gene expression in barley during drought stress at the grain filling stage

SWEET (Sugars Will Eventually be Exported Transporters) genes facilitate the mobilization of photosynthetic products from source leaves to sinks. They contribute to sucrose translocation and respond to abiotic stresses. This research examined the HvSWEET genes within the barley genome, focusing on their phylogenetic relationships, structural characteristics, chromosomal positions, and gene expression profiles in response to drought stress at 21 and 28 days post-anthesis (two important time points in seed filling). In silico analysis revealed 23 SWEET genes in barley, including information on chromosomal location, phylogenetic relationships, gene structures, conserved motifs, and cis-elements in promoter regions. Phylogenetic analysis grouped barley and maize SWEET sequences into five clusters. HvSWEET12/13c/14 genes contain multiple binding sites in their promoter regions, indicating involvement in multiple abiotic/biotic stress responses. Gene expression analysis showed up-regulation of HvSWEET7/12/13c/14 at 21 and 28 days after anthesis under drought conditions. The role of sucrose transport in grain filling at 21 and 28 days after anthesis in barley was highlighted. SWEET transporters influence source/sink relationships, presenting opportunities for genetic modification to enhance stress tolerance. These results offer valuable insights into the various functions of HvSWEET genes and highlight their potential application in enhancing barley resilience against stress.