title: Fructokinase is required for carbon partitioning to cellulose in aspen wood.
abstract: Sucrose is the main transported form of carbon in several plant species, including Populus species. Sucrose metabolism in developing wood has therefore a central role in carbon partitioning to stem biomass. Half of the sucrose-derived carbon is in the form of fructose, but metabolism of fructose has received little attention as a factor in carbon partitioning to walls of wood cells. We show that RNAi-mediated reduction of FRK2 activity in developing wood of hybrid aspen (Populus tremula × tremuloides) led to the accumulation of soluble neutral sugars and a decrease in hexose phosphates and UDP-glucose, indicating that carbon flux to cell-wall polysaccharide precursors is decreased. Reduced FRK2 activity also led to thinner fiber cell walls with a reduction in the proportion of cellulose. No pleiotropic effects on stem height or diameter were observed. The results establish a central role for FRK2 activity in carbon flux to wood cellulose.
authors.affiliation: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE 90183 Umeå, Sweden.
authors.forename: Melissa
authors.initials: M
authors.lastname: Roach
authors.forename: Lorenz
authors.initials: L
authors.lastname: Gerber
authors.forename: David
authors.initials: D
authors.lastname: Sandquist
authors.forename: András
authors.initials: A
authors.lastname: Gorzsás
authors.forename: Mattias
authors.initials: M
authors.lastname: Hedenström
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.forename: Marie Caroline
authors.initials: MC
authors.lastname: Steinhauser
authors.forename: Regina
authors.initials: R
authors.lastname: Feil
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Daniel
authors.forename: Mark
authors.initials: M
authors.lastname: Stitt
authors.forename: Björn
authors.initials: B
authors.lastname: Sundberg
authors.forename: Totte
authors.initials: T
authors.lastname: Niittylä
mesh_terms: D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D005631:Fructokinases / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D055442:Metabolome; D020411:Oligonucleotide Array Sequence Analysis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism; D032107:Populus / Q000201:enzymology* / Q000235:genetics; D034622:RNA Interference; D013395:Sucrose / Q000378:metabolism; D014934:Wood / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D010940:Plant Proteins; D013395:Sucrose; D002244:Carbon; D002482:Cellulose; D005631:Fructokinases; C046173:fructokinase