title: A study of phytohormone biosynthetic gene expression using a circadian clock-related mutant in rice.
abstract: We have recently isolated a rice circadian clock-related mutant carrying a null mutation in Os-GIGANTEA(GI) gene, the solo ortholog of Arabidopsis GI. Time-course global transcriptome analyses of leaves from wild-type and osgi mutant grown in the field have revealed that Os-GI affects gene expression of more than half of genes on rice 44k microarray. To better understand the biological significance of circadian clock function in growth and development of rice, we here investigated the gene expression involved in phytohormone biosynthesis. Here we found that mRNA levels of a few major genes encoding GA2-oxidase which can inactivate bioactive gibberellins (GAs) were remarkably increased in osgi-1 plants. This suggests that Os-GI functions to maintain bioactive GA level through the regulation of the GA-deactivating enzyme genes in rice. Consistently, osgi-1 plants showed semi-dwarf phenotype with reduced internode and leaf sheath elongation.
authors.affiliation: Functional Plant Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Itoh
authors.forename: Takeshi
authors.initials: T
authors.lastname: Izawa
mesh_terms: D057906:Circadian Clocks; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000096:biosynthesis* / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010937:Plant Growth Regulators / Q000096:biosynthesis* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D005875:Gibberellins; D010937:Plant Growth Regulators; D010940:Plant Proteins
references.citation: Nucleic Acids Res. 2011 Jan;39(Database issue):D1141-8
references.pmid: 21045061
references.citation: Annu Rev Plant Biol. 2007;58:183-98
references.pmid: 17472566
references.citation: Plant Cell Physiol. 2008 Oct;49(10):1429-50
references.pmid: 18718932
references.citation: Proc Natl Acad Sci U S A. 2011 May 31;108(22):9292-7
references.pmid: 21576475
references.citation: Philos Trans R Soc Lond B Biol Sci. 2000 Oct 29;355(1402):1499-510
references.pmid: 11128003
references.citation: Plant Physiol. 1999 Feb;119(2):765-74
references.pmid: 9952473
references.citation: Cell. 2008 Apr 4;133(1):177-91
references.pmid: 18394997
references.citation: Plant Physiol. 2004 Apr;134(4):1642-53
references.pmid: 15075394
references.citation: Cell. 2008 Apr 4;133(1):164-76
references.pmid: 18394996
references.citation: EMBO J. 1999 Sep 1;18(17):4679-88
references.pmid: 10469647
references.citation: Plant Physiol. 2007 Sep;145(1):106-18
references.pmid: 17644628
references.citation: Plant Cell. 2008 Oct;20(10):2603-18
references.pmid: 18952778
references.citation: Science. 1999 Sep 3;285(5433):1579-82
references.pmid: 10477524
references.citation: Annu Rev Plant Biol. 2009;60:357-77
references.pmid: 19575587
references.citation: Trends Plant Sci. 2002 Jan;7(1):41-8
references.pmid: 11804826
references.citation: Genome Biol. 2002 Aug 30;3(9):research0048
references.pmid: 12225587
references.citation: Curr Opin Plant Biol. 2011 Feb;14(1):31-7
references.pmid: 20943429
references.citation: Nature. 2007 Aug 9;448(7154):661-5
references.pmid: 17637677
references.citation: Plant Physiol. 1995 May;108(1):337-343
references.pmid: 12228478
references.citation: Plant J. 2001 May;26(4):421-33
references.pmid: 11439129
references.citation: Nature. 2007 Aug 9;448(7154):666-71
references.pmid: 17637675
references.citation: Bioinformatics. 2011 Apr 15;27(8):1094-100
references.pmid: 21330289
references.citation: Plant Physiol. 2005 Jun;138(2):1106-16
references.pmid: 15923331
references.citation: Nat Genet. 2010 Jul;42(7):635-8
references.pmid: 20543848
references.citation: Plant Cell. 2011 May;23(5):1741-55
references.pmid: 21571948