title: HYL1 regulates the balance between adaxial and abaxial identity for leaf flattening via miRNA-mediated pathways.
abstract: HYPONASTIC LEAVES1 (HYL1) is an important regulator of microRNA (miRNA) biogenesis. Incurvature of rosette leaves in loss-of-function mutants of HYL1 implicates the regulation of leaf flatness by HYL1 via miRNA pathways. Recent studies have identified jba-1D, jaw-1D, and oe-160c, the dominant mutants of MIR166g, MIR319a, and MIR160c genes, respectively, which display three types of leaf curvature. However, it remains unclear whether or how HYL1 controls leaf flatness through the pathways mediated by these miRNAs. To define which miRNAs and target genes are relevant to the hyl1 phenotype in terms of leaf incurvature, the effects of three mutated MIRNA genes and their targets on the direction and extent of leaf curvature in hyl1 mutants were examined. The genetic analysis shows that the hyl1 phenotype is strongly rescued by jba-1D, but not by jaw-1D or oe-160c, whereas the mutant phenotypes of jba-1D, jaw-1D, or oe-160c leaves are compromised by the hyl1 allele. Expression analysis indicates that reduced accumulation of miR166, rather than of miR319a or miR160, causes incurvature of hyl1 leaves, and that miR319a-targeted TCP3 positively regulates the adaxial identity gene PHABULOSA while miR160-targeted ARF16 negatively regulates the abaxial identity gene FILAMENTOUS FLOWER. In these cases, the direction and extent of leaf incurvature are associated with the expression ratio of adaxial to abaxial genes (adaxial to abaxial ratio). HYL1 regulates the balance between adaxial and abaxial identity and modulates leaf flatness by preventing leaf incurvature, wavy margins, and downward curvature. It is concluded that HYL1 monitors the roles of miR165/166, miR319a, and miR160 in leaf flattening through the relative activities of adaxial and abaxial identity genes, thus playing an essential role in leaf development.
authors: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Feng Lin Road, Shanghai 200032, China.
authors: Zhongyuan
authors: Z
authors: Liu
authors: Liguo
authors: L
authors: Jia
authors: Han
authors: H
authors: Wang
authors: Yuke
authors: Y
authors: He
references: Semin Cell Dev Biol. 2001 Oct;12(5):363-72
references: 11535044
references: Plant J. 2006 Sep;47(6):841-50
references: 16889646
references: Genes Dev. 1999 Dec 1;13(23):3160-9
references: 10601041
references: J Exp Bot. 2010 Jun;61(10):2757-67
references: 20400533
references: Trends Genet. 2002 Mar;18(3):134-41
references: 11858837
references: Plant Cell. 2000 Dec;12(12):2351-2366
references: 11148283
references: Nature. 2001 Jun 7;411(6838):709-13
references: 11395776
references: RNA. 2006 Feb;12(2):206-12
references: 16428603
references: Curr Opin Plant Biol. 2000 Feb;3(1):17-22
references: 10679447
references: Proc Natl Acad Sci U S A. 2004 Jan 27;101(4):1093-8
references: 14722360
references: Development. 2001 Jun;128(11):1923-31
references: 11493516
references: Science. 2003 Feb 28;299(5611):1404-7
references: 12610308
references: Plant Cell Physiol. 2004 Apr;45(4):369-85
references: 15111711
references: EMBO J. 2004 Aug 18;23(16):3356-64
references: 15282547
references: Genes Dev. 1999 May 1;13(9):1079-88
references: 10323860
references: Annu Rev Plant Biol. 2006;57:19-53
references: 16669754
references: Development. 1999 Sep;126(18):4117-28
references: 10457020
references: Plant Cell. 2002 Nov;14(11):2761-70
references: 12417699
references: Nature. 2005 Oct 13;437(7061):1022-6
references: 16222298
references: Curr Biol. 2003 Oct 14;13(20):1768-74
references: 14561401
references: Plant Cell. 2010 Jul;22(7):2113-30
references: 20628155
references: Plant Cell. 2007 Mar;19(3):914-25
references: 17337628
references: Planta. 2005 May;221(2):231-42
references: 15580355
references: Plant Cell. 2005 May;17(5):1360-75
references: 15829600
references: Curr Biol. 2007 May 1;17(9):818-23
references: 17442570
references: Proc Natl Acad Sci U S A. 2008 Jul 22;105(29):9970-5
references: 18632569
references: Genes Dev. 2002 Jul 1;16(13):1616-26
references: 12101121
references: Plant Physiol. 2003 Jun;132(2):709-17
references: 12805599
references: Development. 2005 Aug;132(16):3657-68
references: 16033795
references: Genes Dev. 2004 May 15;18(10):1187-97
references: 15131082
references: Genetics. 2000 Nov;156(3):1363-77
references: 11063708
references: Plant Mol Biol. 2005 Jan;57(2):173-88
references: 15821876
references: Nature. 2003 Sep 18;425(6955):257-63
references: 12931144
references: Development. 1998 Aug;125(15):2935-42
references: 9655815
references: Plant Cell. 2007 Feb;19(2):473-84
references: 17307931
references: Plant Physiol. 2003 Jul;132(3):1382-90
references: 12857820
references: J Biol Chem. 1995 Mar 17;270(11):6081-7
references: 7890741
references: Plant Cell. 2005 Aug;17(8):2204-16
references: 16006581
references: Curr Biol. 2002 Sep 3;12(17):1484-95
references: 12225663
references: Cell. 1999 Oct 15;99(2):199-209
references: 10535738