The Arabidopsis thaliana TAG1 mutant has a mutation in a diacylglycerol acyltransferase gene
Article first published online: 5 JAN 2002
The Plant Journal
Volume 19, Issue 6, pages 645–653, September 1999
How to Cite
Zou, J., Wei, Y., Jako, C., Kumar, A., Selvaraj, G. and Taylor, D. C. (1999), The Arabidopsis thaliana TAG1 mutant has a mutation in a diacylglycerol acyltransferase gene. The Plant Journal, 19: 645–653. doi: 10.1046/j.1365-313x.1999.00555.x
- Issue published online: 5 JAN 2002
- Article first published online: 5 JAN 2002
- Received 5 July 1999; accepted 19 July 1999.
In Arabidopsis thaliana (ecotype Columbia) mutant line AS11, an EMS-induced mutation at a locus on chromosome II results in a reduced diacylglycerol acyltransferase (DGAT; EC 18.104.22.168) activity, reduced seed triacylglycerol, an altered seed fatty acid composition, and delayed seed development. A mutation has been identified in AS11 in a gene, which we designated as TAG1, that encodes a protein with an amino acid sequence which is similar to a recently reported mammalian DGAT, and, to a lesser extent, to acyl CoA:cholesterol acyltransferases. Molecular analysis revealed that the mutant allele in AS11 has a 147 bp insertion located at the central region of intron 2. At the RNA level, an 81 bp insertion composed entirely of an exon 2 repeat was found in the transcript. While the seed triacylglycerol content is reduced by the lesion in AS11, there is no apparent effect on sterol ester content in the mutant seed. The TAG1 cDNA was over-expressed in yeast, and its activity as a microsomal DGAT confirmed. Therefore, the TAG1 locus encodes a diacylglycerol acyltransferase, and the insertion mutation in the TAG1 gene in mutant AS11 results in its altered lipid phenotype.