title: The plastid hexokinase pHXK: a node of convergence for sugar and plastid signals in Arabidopsis.
abstract: The inhibitors to plastid gene expression (PGE) were effective in preventing nuclear photosynthetic gene expression only if applied within the first 2-3 days of Arabidopsis seedling development. However, the signal transduction processes are still unknown. In this investigation, we found 3% glucose with 1mM chloramphenicol co-treatment repressed LHCB transcript significantly in mature Arabidopsis seedlings, while effective solo glucose treatment needed a concentration of 7%. The repressive effects of glucose and chloramphenicol on LHCB expression were inhibited in phxk (plastid hexokinase) mutant. pHXK enzyme activities, location, function in signal transduction, and cross talk to plastid GUN1 protein (a key signaling factor) were also investigated. The data suggest that pHXK may be a node of convergence for sugar-mediated and PGE-derived signals in Arabidopsis.
authors.affiliation: Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, Chengdu 610064, China.
authors.forename: Zhong-Wei
authors.initials: ZW
authors.lastname: Zhang
authors.forename: Shu
authors.initials: S
authors.lastname: Yuan
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
authors.forename: Nian-Hui
authors.initials: NH
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Cheng
authors.forename: Hong-Hui
authors.initials: HH
authors.lastname: Lin
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D002701:Chloramphenicol / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D017343:Genes, Plant; D005937:Glucaric Acid / Q000494:pharmacology; D006593:Hexokinase / Q000235:genetics / Q000378:metabolism*; D045342:Light-Harvesting Protein Complexes / Q000235:genetics; D008954:Models, Biological; D009154:Mutation; D010641:Phenotype; D030821:Plants, Genetically Modified; D018087:Plastids / Q000201:enzymology* / Q000235:genetics; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; C519677:GUN1 protein, Arabidopsis; D045342:Light-Harvesting Protein Complexes; D002701:Chloramphenicol; D006593:Hexokinase; D005937:Glucaric Acid