How do sugarbeets accumulate sucrose?

Authors: Fugate, Karen

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The U.S. sugarbeet industry is a $3.2 billion industry that is founded on the unusual ability of the sugarbeet plant to accumulate large quantities of sucrose in a central taproot. Although knowledge of the processes involved in sucrose accumulation in the sugarbeet taproot would assist breeders in selecting for improved sucrose yield and improve our understanding of how production practices and environmental factors affect sucrose content, surprisingly little is known of these processes or the factors that regulate them. Therefore, identification of the genes, enzymes, and physiological processes involved in sucrose accumulation is a central goal for the sugarbeet industry. Past research established that sucrose catabolism in the taproot is a primary determinant of sucrose yield. But how sucrose catabolism in the taproot promotes sucrose accumulation in this organ is unclear. Studies, therefore, were taken to identify the enzymes responsible for sucrose catabolism in the sugarbeet taproot, isolate the genes involved in sucrose catabolism during sugar accumulation, and determine the physiological roles of these genes by characterizing their molecular properties, altering their expression by genetic transformation, and intercellularly localizing their expression. From this research, sucrose synthase, a sucrolytic enzyme encoded by two genes, was identified as having a central role in sugarbeet sucrose accumulation. Evidence was also generated suggesting that this enzyme promotes sucrose accumulation by its ability to fuel sucrose sequestration in the vacuoles of sugar-storing cells and by maintaining the shoot-to-root sucrose concentration gradient that promotes sucrose translocation to the root.