title: Tonoplast Sugar Transporters (SbTSTs) putatively control sucrose accumulation in sweet sorghum stems.
abstract: Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed.
authors.affiliation: a Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri , 116 Tucker Hall, Columbia , MO , USA.
authors.forename: Saadia
authors.initials: S
authors.lastname: Bihmidine
authors.affiliation: a Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri , 116 Tucker Hall, Columbia , MO , USA.
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Julius
authors.affiliation: b Department of Agronomy and Horticulture , University of Nebraska-Lincoln , 365 Keim Hall, Lincoln , NE , USA.
authors.forename: Ismail
authors.initials: I
authors.lastname: Dweikat
authors.affiliation: a Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri , 116 Tucker Hall, Columbia , MO , USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Braun
mesh_terms: D050260:Carbohydrate Metabolism / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D018515:Plant Leaves / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism*; D017423:Sequence Analysis, RNA; D045868:Sorghum / Q000235:genetics / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D026901:Membrane Transport Proteins; D010940:Plant Proteins; D013395:Sucrose
keywords: Carbohydrate partitioning; TSTs; sorghum bicolor; sucrose; SWEETs