|LAFTA, ABBAS - North Dakota State University|
|KHAN, MOHAMED - North Dakota State University|
|FINGER, FERNANDO - Universidade Federal De Vicosa|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/13/2018
Publication Date: 10/13/2018
Citation: Fugate, K.K., Lafta, A.M., Eide, J.D., Khan, M.F., Finger, F.L. 2018. Bidirectional sucrose transporters are upregulated during sugar beet root storage [abstract]. American Society of Sugar Beet Technologists, February 25-28, 2019, Anaheim, CA.
Technical Abstract: During production, large concentrations of sucrose accumulate in the parenchyma cells of the sugar beet taproot. Accumulation is possible because sucrose is sequestered in the vacuole of these cells, thereby separating sucrose from the sucrose-degrading enzymes which are predominantly present in the cytoplasm. During storage, sequestered sucrose is remobilized to provide the substrates and energy needed to heal wounds, maintain metabolism, and to fuel plant defenses against storage pathogens. How sucrose is remobilized to fuel this metabolism, however, is unknown, although this information would provide valuable insight into the mechanisms by which sucrose is lost during storage. To identify metabolic and genetic factors that may be involved in sucrose remobilization and degradation in storage, transcriptional and metabolic changes were determined in roots stored at 5 and 12°C for 0, 12, 40 or 120 days. While the sucrose concentration in the sugar beet taproot declined, only small changes in expression were noted for the sucrose synthase and invertase genes which are directly responsible for sucrose cleavage during storage. However, three bidirectional sucrose transporter genes, that were expressed at very low levels at time of harvest, were highly upregulated during storage, with expression increases of 26, 103, and 52,000-fold, respectively, observed for the three genes. The expression of bidirectional sucrose transporters has not been previously reported in the sugar beet taproot, and no information regarding their function is currently available. However, bidirectional sugar transporters facilitate sugar transport across vacuolar and plasma-membranes in other plant species. This information, in conjunction with the large increase in their expression that occurred during storage, suggest that bidirectional sugar transporters may function in sucrose remobilization in postharvest sugar beet taproots.