title: CLE6 expression recovers gibberellin deficiency to promote shoot growth in Arabidopsis.
abstract: Small peptides act as local signals during plant development, but few studies have examined their interaction with phytohormone signaling. Here, we show that application of gibberellin (GA) to Arabidopsis shoots induces substantial accumulation of transcripts encoded by CLE6, a member of the CLAVATA/ESR-RELATED (CLE) gene family, in the root stele, followed by promotion of organ growth by CLE6 in GA-deficient plants. The long-distance effect of GA4 was demonstrated by the observation that its application to the shoot apex of the GA-deficient mutant ga3ox1/ga3ox2 rescued the short-root phenotype. Microarray analysis was used to identify root-expressed genes that respond to systemic application of GA, and CLE6 was selected for further analysis. CLE6 was highly expressed in roots at the young seedling stage, and CLE6 promoter activity was strong in hypocotyls and roots, especially in root stele cells at branch points. Application of CLE6 peptide had no obvious effect on the growth and development of GA-deficient mutant plants. Nonetheless, the fact that ectopic over-expression of CLE6 in the GA-deficient mutant promoted root growth and branching, petiole elongation, bolting rate and stem length showed that CLE6 expression partially compensates for the GA deficiency. Reciprocal grafting of GA-deficient mutant plants to 35S::CLE6 transformants complemented the shoot phenotype associated with GA deficiency, demonstrating the systemic effect of CLE6 from root to shoot. These data suggest that root-expressed CLE6 is systemically involved in shoot growth under GA action in Arabidopsis.
authors: Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.
authors: Haniyeh
authors: H
authors: Bidadi
authors: Keita
authors: K
authors: Matsuoka
authors: Kimiyo
authors: K
authors: Sage-Ono
authors: Jun
authors: J
authors: Fukushima
authors: Weerasak
authors: W
authors: Pitaksaringkarn
authors: Masashi
authors: M
authors: Asahina
authors: Shinjiro
authors: S
authors: Yamaguchi
authors: Shinichiro
authors: S
authors: Sawa
authors: Hiroo
authors: H
authors: Fukuda
authors: Yoshikatsu
authors: Y
authors: Matsubayashi
authors: Michiyuki
authors: M
authors: Ono
authors: Shinobu
authors: S
authors: Satoh
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism* / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C000594051:CLE6 protein, Arabidopsis; D005875:Gibberellins; D036341:Intercellular Signaling Peptides and Proteins; D010937:Plant Growth Regulators; D012333:RNA, Messenger
keywords: Arabidopsis thaliana; grafting; hormone signaling; long distance signaling; root stele; small peptides