Abstract
Abscisic acid (ABA) regulates developmental processes and stress responses during seed maturation in plants. In this study we analyzed a role of a phosphatidic acid (PA) in ABA signal transduction during seed germination. A physiological analysis showed PA triggers early signal transduction events that lead to the ABA responses during seed germination.
To test the possible role of PA during germination, we measured increased PA production during seed germination. Phosphatidic acid phosphatase (PAP) is an enzyme that catalyzes PA to diacylglycerol. We analyzed a role of PAP in PA metabolism during germination. There are four genes for Arabidopsis genome. To identify functional PAP genes during germination process, we analyzed expression of four PAP genes and phenotypes of their knockout mutants. The PAP2-knockout plant revealed a hypersensitive phenotype to ABA and accumulated PA during germination. These results suggest that PAP2 is involved in ABA response during seed germination.
