title: Expression of Arabidopsis SHORT INTERNODES/STYLISH family genes in auxin biosynthesis zones of aerial organs is dependent on a GCC box-like regulatory element.
abstract: Auxin/indole-3-acetic acid (IAA) biosynthesis in Arabidopsis (Arabidopsis thaliana) plays a major role in growth responses to developmental and genetic signals as well as to environmental stimuli. Knowledge of its regulation, however, remains rudimentary, and few proteins acting as transcriptional modulators of auxin biosynthesis have been identified. We have previously shown that alteration in the expression level of the SHORT INTERNODES/STYLISH (SHI/STY) family member STY1 affects IAA biosynthesis rates and IAA levels and that STY1 acts as a transcriptional activator of genes encoding auxin biosynthesis enzymes. Here, we have analyzed the upstream regulation of SHI/STY family members to gain further insight into transcriptional regulation of auxin biosynthesis. We attempted to modulate the normal expression pattern of STY1 by mutating a putative regulatory element, a GCC box, located in the proximal promoter region and conserved in most SHI/STY genes in Arabidopsis. Mutations in the GCC box abolish expression in aerial organs of the adult plant. We also show that induction of the transcriptional activator DORNRÖSCHEN-LIKE (DRNL) activates the transcription of STY1 and other SHI/STY family members and that this activation is dependent on a functional GCC box. Additionally, STY1 expression in the strong drnl-2 mutant or the drn drnl-1 puchi-1 triple mutant, carrying knockdown mutations in both DRNL and its close paralogue DRN as well as one of their closest homologs, PUCHI, was significantly reduced, suggesting that DRNL regulates STY1 during normal plant development and that several other genes might have redundant functions.
authors: Uppsala BioCenter, Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden.
authors: D Magnus
authors: DM
authors: Eklund
authors: Izabela
authors: I
authors: Cierlik
authors: Veronika
authors: V
authors: Ståldal
authors: Andrea R
authors: AR
authors: Claes
authors: Daniel
authors: D
authors: Vestman
authors: John
authors: J
authors: Chandler
authors: Eva
authors: E
authors: Sundberg
mesh_terms: D000598:Amino Acids, Cyclic / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D018548:Cotyledon / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D007210:Indoleacetic Acids / Q000378:metabolism*; D009154:Mutation; D059372:Nucleotide Motifs / Q000235:genetics*; D035261:Plant Components, Aerial / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000598:Amino Acids, Cyclic; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D014157:Transcription Factors; C517039:DRNL protein, Arabidopsis; C524429:Puchi protein, Arabidopsis; C513747:STY1 protein, Arabidopsis; C023863:1-aminocyclopropane-1-carboxylic acid