Skip to main content
SLU publication database (SLUpub)

Conference abstract2005

Effect of overexpression of the AtPDAT-1 gene (At5g13640) on growth rate of seedlings and oil content in the seeds of transformed Arabidopsis plants

Banaś Walentyna, Lenman Marit, Carlsson Anders, Banaś Antoni, Stymne Sten

Abstract

PDAT (phospholipid: diacylglycerol acyltransferase) catalyse an acyl-CoA independent synthesis of TAG. Enzyme utilises phospholipids as acyl donors and diacylglycerols as acyl acceptor. Beside the enzymes of DAGAT type it is, up to now, the only identified type of enzyme capable to synthesise triacylglycerols molecules. Therefore it was reasonable to believe that overexpression of this enzyme will increase the amount of synthesised TAG. The experiment with baking Yeast (in which the PDAT was first identified) confirmed this assumption. Transformed Yeast with elevated PDAT activity was able to produce up to double amount of triacylglycerols compared to the control ones. Based on the sequence homology to the Yeast PDAT gene, we were able to identified and cloning from Arabidopsis genome, its homologue: At5g13640, and during biochemical characterisation proved that the enzyme encoding by this gene is a plant PDAT. From the transformed with At5g13640 gene Arabidopsis plant (T2 generation, 35S promoter) we selected three with different level of gene expression (correlated well with PDAT activity) for the phenotypic study of PDAT overexpression. Evaluation of the oil content in the seeds of these transformants did not showed, similar to Yeast, high increase in TAG content, however the seeds of middle and high overexpressers have a few percentages higher amount of oil content compered do the lowest one. When the seeds of these transformants were germinated on agar with kanamycin (selecting agent) the seedlings were smaller than corresponding control ones germinated on agar without antibiotic. However, when both transformed and not transformed seeds were germinated without the presence of kanamycin, the transformed plants growth much faster than the control ones (after 19 days its fresh weight were about 1,5 times of the control ones). When the transformed seedlings germinated in the presence of kanamycin were transformed to the medium without this antibiotic, or to the soil, these plants surpassed after a 3-4 weeks the control plants in the growth. To confirm these observation, in the further study we selected a several homozygotes, heterozygotes and null segregants and used these T3 plants for evaluation of the effect of PDAT overexpression on oil content in the seeds and on the growth rate of young seedlings. Basically, the obtained results confirmed data with T2 plants. Between the homozygous and heterozygous plants we found a few with higher seeds oil content than in seeds of null segregant plants, however the difference was not very significant (only a few percentages higher than average oil content in the control seeds). Also a young seedlings of a few homozygous plants growth faster than the control ones, however there was not a correlation between oil content in the seeds and rate of growth of the seedlings

Published in

Conference

2nd Swedish Plant Lipid Meeting

      SLU Authors

    • Carlsson, Anders

      • Department of Crop Science, Swedish University of Agricultural Sciences