title: Osmosensitive changes of carbohydrate metabolism in response to cellulose biosynthesis inhibition.
abstract: Cellulose is the most abundant biopolymer in the world, the main load-bearing element in plant cell walls, and represents a major sink for carbon fixed during photosynthesis. Previous work has shown that photosynthetic activity is partially regulated by carbohydrate sinks. However, the coordination of cellulose biosynthesis with carbohydrate metabolism and photosynthesis is not well understood. Here, we demonstrate that cellulose biosynthesis inhibition (CBI) leads to reductions in transcript levels of genes involved in photosynthesis, the Calvin cycle, and starch degradation in Arabidopsis (Arabidopsis thaliana) seedlings. In parallel, we show that CBI induces changes in carbohydrate distribution and influences Rubisco activase levels. We find that the effects of CBI on gene expression and carbohydrate metabolism can be neutralized by osmotic support in a concentration-dependent manner. However, osmotic support does not suppress CBI-induced metabolic changes in seedlings impaired in mechanoperception (mid1 complementing activity1 [mca1]) and osmoperception (cytokinin receptor1 [cre1]) or reactive oxygen species production (respiratory burst oxidase homolog DF [rbohDF]). These results show that carbohydrate metabolism is responsive to changes in cellulose biosynthesis activity and turgor pressure. The data suggest that MCA1, CRE1, and RBOHDF-derived reactive oxygen species are involved in the regulation of osmosensitive metabolic changes. The evidence presented here supports the notion that cellulose and carbohydrate metabolism may be coordinated via an osmosensitive mechanism.
authors.affiliation: Division of Cell and Molecular Biosciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Wormit
authors.forename: Salman M
authors.initials: SM
authors.lastname: Butt
authors.forename: Issariya
authors.initials: I
authors.lastname: Chairam
authors.forename: Joseph F
authors.initials: JF
authors.lastname: McKenna
authors.forename: Adriano
authors.initials: A
authors.lastname: Nunes-Nesi
authors.forename: Lars
authors.initials: L
authors.lastname: Kjaer
authors.forename: Kerry
authors.initials: K
authors.lastname: O'Donnelly
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Woscholski
authors.forename: M C Laura
authors.initials: MC
authors.lastname: Barter
authors.forename: Thorsten
authors.initials: T
authors.lastname: Hamann
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001549:Benzamides / Q000494:pharmacology; D050260:Carbohydrate Metabolism; D002470:Cell Survival; D002482:Cellulose / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D004789:Enzyme Activation; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D009997:Osmotic Pressure; D010788:Photosynthesis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D029681:Arabidopsis Proteins; D001549:Benzamides; C520286:MCA1 protein, Arabidopsis; D008565:Membrane Proteins; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; C054765:rca protein, plant; D011092:Polyethylene Glycols; C057467:isoxaben; D002482:Cellulose; C568857:AT5G47910 protein, Arabidopsis; D019255:NADPH Oxidases; D011494:Protein Kinases; C421783:WOL protein, Arabidopsis