Crosstalk between Phospholipase D and Sphingosine Kinase in Plant Stress Signaling

The activation of phospholipase D (PLD) produces phosphatidic acid (PA), whereas plant sphingosine kinase (SPHK) phosphorylates long-chain bases to generate long-chain base-1-phosphates such as phytosphingosine-1-phosphate (phyto-S1P). PA and phyto-S1P have been identified as lipid messengers. Recent studies have shown that PA interacts directly with SPHKs in Arabidopsis, and that the interaction promotes SPHK activity. However, SPHK and phyto-S1P act upstream of PLDα1 and PA in the stomatal response to abscisic acid (ABA). These findings indicate that SPHK/phyto-S1P and PLD/PA are co-dependent in the amplification of lipid messengers, and that crosstalk between the sphingolipid- and phospholipid-mediated signaling pathways may play important roles in plant stress signaling

Increasing the Content of Long Chain Fatty Acids in Seed Oil

Provided are plants that express, or overexpress, a pPLAIIIδ protein. Constitutive or seed-specific expression of pPLAIIIδ protein in Arabidopsis increases seed oil content, the amount of C20 and C22 fatty acids, and the amount of C56, C58, and C60 triacylglycerols, effectively resulting in significantly higher oil yield per plant. Use of pPLAIIIδ is therefore an effective biotechnological tool to significantly increase plant yield, including oil, and the amount of high value long chain fatty acids in agricultural and horticultural crops, especially oilseed crops.https://irl.umsl.edu/patents/1064/thumbnail.jp