The Acyl-CoA Synthetase Encoded by LACS2 Is Essential for Normal Cuticle Development in Arabidopsis
| Autor: | Judy Schnurr, John Browse, Jay Shockey |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
DNA
Plant Cuticle Mutant Molecular Sequence Data Arabidopsis Germination Plant Science Cutin Genes Plant Isozyme Membrane Lipids Coenzyme A Ligases Arabidopsis thaliana Research Articles biology Base Sequence Genetic Complementation Test Wild type food and beverages Cell Biology biology.organism_classification Plants Genetically Modified Reverse genetics Recombinant Proteins Isoenzymes Plant Leaves Phenotype Biochemistry RNA Plant Mutation Microscopy Electron Scanning |
| Popis: | Long-chain acyl-CoA synthetase (LACS) activities are encoded by a family of at least nine genes in Arabidopsis (Arabidopsis thaliana). These enzymes have roles in lipid synthesis, fatty acid catabolism, and the transport of fatty acids between subcellular compartments. Here, we show that the LACS2 gene (At1g49430) is expressed in young, rapidly expanding tissues, and in leaves expression is limited to cells of the adaxial and abaxial epidermal layers, suggesting that the LACS2 enzyme may act in the synthesis of cutin or cuticular waxes. A lacs2 null mutant was isolated by reverse genetics. Leaves of mutant plants supported pollen germination and released chlorophyll faster than wild-type leaves when immersed in 80% ethanol, indicating a defect in the cuticular barrier. The composition of surface waxes extracted from lacs2 leaves was similar to the wild type, and the total wax load was higher than the wild type (111.4 microg/dm(2) versus 76.4 microg/dm(2), respectively). However, the thickness of the cutin layer on the abaxial surface of lacs2 leaves was only 22.3 +/- 1.7 nm compared with 33.0 +/- 2.0 nm for the wild type. In vitro assays showed that 16-hydroxypalmitate was an excellent substrate for recombinant LACS2 enzyme. We conclude that the LACS2 isozyme catalyzes the synthesis of omega-hydroxy fatty acyl-CoA intermediates in the pathway to cutin synthesis. The lacs2 phenotype, like the phenotypes of some other cutin mutants, is very pleiotropic, causing reduced leaf size and plant growth, reduced seed production, and lower rates of seedling germination and establishment. The LACS2 gene and the corresponding lacs2 mutant will help in future studies of the cutin synthesis pathway and in understanding the consequences of reduced cutin production on many aspects of plant biology. |
| Databáze: | OpenAIRE |
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