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The Arabidopsis transcription factor LUH/MUM1 is required for extrusion of seed coat mucilage.
- Source :
-
Plant physiology [Plant Physiol] 2011 Jun; Vol. 156 (2), pp. 491-502. Date of Electronic Publication: 2011 Apr 25. - Publication Year :
- 2011
-
Abstract
- During differentiation, the Arabidopsis (Arabidopsis thaliana) seed coat epidermal cells secrete mucilage composed primarily of rhamnogalacturonan I that is extruded from the seed coat upon imbibition. The mucilage of the mucilage modified1 (mum1) mutant contains rhamnogalacturonan I that is more highly branched and lacks the ability to be extruded when exposed to water. Our cloning of the MUM1 gene shows that it encodes a putative transcription factor, LEUNIG_HOMOLOG (LUH). Cellular localization and transcriptional assay results suggest that LUH/MUM1 is a nucleus-localized transcriptional activator. LUH/MUM1 is expressed in all the tissues examined, including the seed coat. Quantitative reverse transcription-polymerase chain reaction data suggest that LUH/MUM1 is expressed throughout seed coat development, reaching peak expression late in differentiation. LUH1/MUM1 expression in plants homozygous for mutations in several genes encoding regulators of seed coat mucilage was unchanged. Thus, LUH/MUM1 expression appears to be independent of other transcription factors known to regulate aspects of seed coat mucilage biology. The expression in the luh/mum1 mutant of three genes encoding enzymes needed for mucilage extrusion, MUM2, SUBSILIN PROTEASE1.7, and β-XYLOSIDASE1, was reduced relative to that of the wild type. Overexpression of MUM2 could partially rescue the mum1 phenotype. These data suggest that LUH/MUM1 is a positive regulator of all three genes.
- Subjects :
- Alkalies pharmacology
Arabidopsis drug effects
Arabidopsis genetics
Arabidopsis Proteins chemistry
Arabidopsis Proteins genetics
Carbohydrates analysis
Chelating Agents pharmacology
Cloning, Molecular
Gene Expression Regulation, Plant drug effects
Genetic Linkage drug effects
Models, Biological
Mutation genetics
Phenotype
Plants, Genetically Modified
Protein Transport drug effects
Repressor Proteins chemistry
Repressor Proteins genetics
Seeds drug effects
Seeds genetics
Subcellular Fractions metabolism
Transcription Factors chemistry
Transcription Factors genetics
Transcriptional Activation drug effects
Transcriptional Activation genetics
Adhesives metabolism
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Repressor Proteins metabolism
Seeds metabolism
Transcription Factors metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1532-2548
- Volume :
- 156
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Plant physiology
- Publication Type :
- Academic Journal
- Accession number :
- 21518777
- Full Text :
- https://doi.org/10.1104/pp.111.172023