Abstract
The hormone abscisic acid (ABA) regulates developmental processes and stress responses in plants. In this study we attention to phospholipid-based transduction mechanisms in seed germination. A physiological experiment showed PA triggers early signal transduction events that lead to the ABA responses during germination.
To test the possible role of PA in ABA signalling during germination, we measured PA production and revealed that PA increased transiently. Metabolic enzymes regulate lipid production. Therefore we investigate two kinds of metabolic enzymes, Phospholipase D (PLD) that is a PA producing enzyme and Phosphatidic acid phosphatase (PAP) that is a PA decreasing enzyme. To isolate the functional PLD gene and PAP gene during germination process, we performed expression analysis and obtained knockout plants for these candidates. The PAP knockout indicated a hypersensitive to ABA. The PLD knockout showed a reduced seed dormancy. These results suggest that PA is involved in seed dormancy and germination.
