Alteration of Fatty Acid Compositions in A Starch-deficient Mutant Arabidopsis thaliana (adg1-1) during Seed Development

Abstract

Disruption of the ADG gene in Arabidopsis results in 6% increase of total fatty acids in mature desiccated seeds. A starchless mutant of Arabidopsis thaliana, ADP glucose pyrophosphorylase (adg1-1) has been investigated concerning the lack of starch in its leaves. In this work of metabolic analysis of adg1-1 mutant, there was very little or no starch accumulation throughout seed development. Even though the growth of these mutant plants was delayed, seed development of the mutants did not show much difference from the wild type. In mature desiccated seeds, there was no significant difference in the seed dry weight of the mutant compared to the wild type. The adg1-1 mutant showed a shift in carbon partitioning to fatty acid (FA) and sucrose accumulation. Major changes have occurred in FA 18.0 (stearic), FA 18.1 (oleic) and FA 18.2 (linoleic). In mature seeds of adg1-1, there was a 70% increase in FA 18.2, a 75% increase in FA 18.1 and a 76% reduction in FA 18.0. The results show that the assimilate partitioning within Arabidopsis seeds has the potential to be altered by relatively simple genetic manipulations. However, the mechanisms by which these changes occurred remain unknown.