RRC ID 36150
著者 Tsuda K, Ito Y, Sato Y, Kurata N.
タイトル Positive autoregulation of a KNOX gene is essential for shoot apical meristem maintenance in rice.
ジャーナル Plant Cell
Abstract Self-maintenance of the shoot apical meristem (SAM), from which aerial organs are formed throughout the life cycle, is crucial in plant development. Class I Knotted1-like homeobox (KNOX) genes restrict cell differentiation and play an indispensable role in maintaining the SAM. However, the mechanism that positively regulates their expression is unknown. Here, we show that expression of a rice (Oryza sativa) KNOX gene, Oryza sativa homeobox1 (OSH1), is positively regulated by direct autoregulation. Interestingly, loss-of-function mutants of OSH1 lose the SAM just after germination but can be rescued to grow until reproductive development when they are regenerated from callus. Double mutants of osh1 and d6, a loss-of-function mutant of OSH15, fail to establish the SAM both in embryogenesis and regeneration. Expression analyses in these mutants reveal that KNOX gene expression is positively regulated by the phytohormone cytokinin and by KNOX genes themselves. We demonstrate that OSH1 directly binds to five KNOX loci, including OSH1 and OSH15, through evolutionarily conserved cis-elements and that the positive autoregulation of OSH1 is indispensable for its own expression and SAM maintenance. Thus, the maintenance of the indeterminate state mediated by positive autoregulation of a KNOX gene is an indispensable mechanism of self-maintenance of the SAM.
巻・号 23(12)
ページ 4368-81
公開日 2011-12-1
DOI 10.1105/tpc.111.090050
PII tpc.111.090050
PMID 22207572
PMC PMC3269871
MeSH Base Sequence Binding Sites Cloning, Molecular Conserved Sequence Cytokinins DNA, Plant / genetics Escherichia coli / genetics Escherichia coli / metabolism Gene Expression Regulation, Developmental Gene Expression Regulation, Plant Genes, Homeobox Genes, Plant Genetic Complementation Test Genetic Loci Germination Homeodomain Proteins / genetics Homeodomain Proteins / metabolism* Meristem / embryology Meristem / genetics Meristem / growth & development* Meristem / metabolism Molecular Sequence Data Mutation Oryza / embryology Oryza / genetics* Oryza / growth & development Oryza / metabolism Plant Leaves / genetics Plant Leaves / growth & development Plant Leaves / metabolism Plant Proteins / genetics Plant Proteins / metabolism* Plants, Genetically Modified / embryology Plants, Genetically Modified / genetics Plants, Genetically Modified / growth & development Plants, Genetically Modified / metabolism Plasmids / genetics Plasmids / metabolism Trans-Activators / genetics Trans-Activators / metabolism* Transformation, Genetic
IF 9.618
引用数 70
WOS 分野 PLANT SCIENCES BIOCHEMISTRY & MOLECULAR BIOLOGY CELL BIOLOGY
リソース情報
イネ Induced mutation lines