Cytidinediphosphate‐diacylglycerol synthase 5 is required for phospholipid homeostasis and is negatively involved in hyperosmotic stress tolerance

<div class="line" id="line-15"> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> Cytidinediphosphate diacylglycerol synthase (CDS ) uses phosphatidic acid (PA ) and cytidinetriphosphate to produce cytidinediphosphate&hyphen;diacylglycerol, an intermediate for phosphatidylglycerol (PG ) and phosphatidylinositol (PI ) synthesis. This study shows that CDS 5, one of the five CDS s of the&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> Oryza sativa&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> (rice) genome, has multifaceted effects on plant growth and stress responses. The loss of CDS 5 resulted in a decrease in PG and PI levels, defective thylakoid membranes, pale leaves in seedlings and growth retardation. In addition, the loss of CDS 5 led to an elevated PA level and enhanced hyperosmotic tolerance. The inhibition of phospholipase&nbsp;D (PLD )&hyphen;derived PA formation in&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> cds5&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> restored the hyperosmotic stress tolerance of the mutant phenotype to that of the wild type, suggesting that CDS 5 functions as a suppressor in PLD &hyphen;derived PA signaling and negatively affects hyperosmotic stress tolerance. </span></div>