GmSWEET29 and Paralog GmSWEET34 Are Differentially Expressed between Soybeans Grown in Eastern and Western Canada


Julia C. Hooker, Elroy R. Cober, Ashkan Golshani, Bahram Samanfar: GmSWEET29 and Paralog GmSWEET34 Are Differentially Expressed between Soybeans Grown in Eastern and Western Canada. Carleton Life Science day 6, 2023 Canada.


The growing demands for crop production to provide food security are driving an urgent need to establish more strategic and efficient agriculture worldwide. Soybean [Glycine max (L.) Merr.] is an economically important crop in Canada with widespread uses in human consumption, animal feed, biotechnology and sustainable agricultural practices. Over the past two decades soybeans grown in Western Canada have persistently had lower seed protein (~1–5%) than those grown in Eastern Canada. The SWEET (Sugars Will Eventually be Exported Transporter) proteins are a family of membrane bound sugar transporters recently identified to play roles in seed protein and oil accumulation in soybean. To understand the discrepancy in seed protein content between Eastern- and Western-grown soybeans, RNA-seq and differential expression analysis were used to investigate SWEET expression patterns. Ten soybean genotypes, ranging from low to high in seed protein content, were grown in four locations across Eastern (Ottawa; control) and Western (Morden, Brandon, and Saskatoon; experimental) Canada. Differential expression analysis revealed 34 differentially expressed SWEET genes, including three Arabidopsis SWEET homologs without a G. max SWEET identity. This study found that paralogs GmSWEET29 and paralog GmSWEET34 (clade I hexose transporters) that were consistently upregulated across all ten genotypes in each of the Western locations over three years. GmSWEET20 and paralog GmSWEET12 (clade II hexose transporters) were persistently downregulated in the Western locations over multiple years. GmSWEET29 and GmSWEET34 are likely candidates underlying the lower seed protein content of Western soybeans. These findings are valuable for improving soybean agriculture in Western growing regions via marker assisted selection, and establishing more strategic and efficient agricultural practices.

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