Very-long-chain fatty acids are required for cell plate formation during cytokinesis in Arabidopsis thaliana

Acyl chain length is thought to be crucial for biophysical properties of the membrane, in particular during cell division, when active vesicular fusion is necessary. In higher plants, the process of cytokinesis is unique, because the separation of the two daughter cells is carried out by de novo vesicular fusion to generate a laterally expanding cell plate. In Arabidopsis thaliana, very-long-chain fatty acid (VLCFA) depletion caused by a mutation in the microsomal elongase gene PASTICCINO2 (PAS2) or by application of the selective elongase inhibitor flufenacet altered cytokinesis. Cell plate expansion was delayed and the formation of the endomembrane tubular network altered. These defects were associated with specific aggregation of the cell plate markers YFP-Rab-A2a and KNOLLE during cytokinesis. Changes in levels of VLCFA also resulted in modification of endocytosis and sensitivity to brefeldin A. Finally, the cytokinesis impairment in pas2 cells was associated with reduced levels of very long fatty acyl chains in phospholipids. Together, our findings demonstrate that VLCFA-containing lipids are essential for endomembrane dynamics during cytokinesis.