Specification of leaf polarity in Arabidopsis via the trans-acting siRNA pathway

Garcia, D., Collier, S. A., Byrne, M. E., Martienssen, R. A. (May 2006) Specification of leaf polarity in Arabidopsis via the trans-acting siRNA pathway. Curr Biol, 16 (9). pp. 933-8. ISSN 0960-9822 (Print)

URL: http://www.ncbi.nlm.nih.gov/pubmed/16682355
DOI: 10.1016/j.cub.2006.03.064

Abstract

Plants leaves develop proximodistal, dorsoventral (adaxial-abaxial), and mediolateral patterns following initiation. The Myb domain gene PHANTASTICA (PHAN) is required for adaxial fate in many plants , but the Arabidopsis ortholog ASYMMETRIC LEAVES1 (AS1) has milder effects, suggesting that alternate or redundant pathways exist . We describe enhancers of as1 with more elongate and dissected leaves. As well as RDR6, an RNA-dependent RNA polymerase previously proposed to influence as1 through microRNA , these enhancers disrupt ARGONAUTE7 (AGO7)/ZIPPY, SUPPRESSOR OF GENE SILENCING3 (SGS3), and DICER-LIKE4 (DCL4), which instead regulate trans-acting small interfering RNA (ta-siRNA) . Microarray analysis revealed that the AUXIN RESPONSE FACTOR genes ETTIN (ETT)/ARF3 and ARF4 were upregulated in ago7, whereas FILAMENTOUS FLOWER (FIL) was upregulated only in as1 ago7 double mutants. RDR6 and SGS3 likewise repress these genes, which specify abaxial fate . We show that the trans-acting siRNA gene TAS3, which targets ETT and ARF4, is expressed in the adaxial domain, and ett as1 ago7 triple mutants resemble as1. Thus FIL is downregulated redundantly by AS1 and by TAS3, acting through ETT, revealing a role for ta-siRNA in leaf polarity. RDR6 and DCL4 are required for systemic silencing, perhaps implicating ta-siRNA as a mobile signal.

Item Type: Paper
Uncontrolled Keywords: Arabidopsis genetics growth development Arabidopsis Proteins genetics physiology Body Patterning genetics physiology DNA-Binding Proteins physiology Genes Homeobox Mutation Nuclear Proteins physiology Plant Leaves growth & development RNA Small Interfering metabolism physiology Trans-Activators physiology Transcription Factors genetics/physiology
Subjects: organism description > plant > Arabidopsis
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > RNA polymerase
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > argonaute proteins
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > miRNA
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > miRNA

bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > genes: types > phantastica
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > siRNA
CSHL Authors:
Communities: CSHL labs > Martienssen lab
Depositing User: CSHL Librarian
Date: 9 May 2006
Date Deposited: 19 Dec 2011 15:42
Last Modified: 09 Apr 2014 20:39
Related URLs:
URI: http://repository.cshl.edu/id/eprint/22795

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