title: Expression of aspartyl protease and C3HC4-type RING zinc finger genes are responsive to ascorbic acid in Arabidopsis thaliana.
abstract: Ascorbate (AsA) is a redox buffer and enzyme cofactor with various proposed functions in stress responses and growth. The aim was to identify genes whose transcript levels respond to changes in leaf AsA. The AsA-deficient Arabidopsis mutant vtc2-1 was incubated with the AsA precursor L-galactono-1,4-lactone (L-GalL) to increase leaf AsA concentration. Differentially expressed genes screened by DNA microarray were further characterized for AsA responsiveness in wild-type plants. The analysis of 14 candidates by real-time PCR identified an aspartyl protease gene (ASP, At1g66180) and a C3HC4-type RING zinc finger gene (AtATL15, At1g22500) whose transcripts were rapidly responsive to increases in AsA pool size caused by L-GalL and AsA supplementation and light. Transgenic Arabidopsis plants expressing an AtATL15 promoter::luciferase reporter confirmed that the promoter is L-GalL, AsA, and light responsive. The expression patterns of ASP and AtATL15 suggest they have roles in growth regulation. The promoter of AtATL15 is responsive to AsA status and will provide a tool to investigate the functions of AsA in plants further.
authors.affiliation: Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan.
authors.forename: Yongshun
authors.initials: Y
authors.lastname: Gao
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nishikawa
authors.forename: Adebanjo Ayobamidele
authors.initials: AA
authors.lastname: Badejo
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shibata
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sawa
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Maruta
authors.forename: Shigeru
authors.initials: S
authors.lastname: Shigeoka
authors.forename: Nicholas
authors.initials: N
authors.lastname: Smirnoff
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ishikawa
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001205:Ascorbic Acid / Q000494:pharmacology*; D057055:Aspartic Acid Proteases / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D013400:Sugar Acids / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D013400:Sugar Acids; C007813:galactonolactone; D057055:Aspartic Acid Proteases; D001205:Ascorbic Acid