HYCCIN2 is essential for recruiting the SH3P2-DRP1A complex to the cell plate in Arabidopsis embryos

Cytokinesis is the final stage of cell division, during which the cytoplasm is divided into two daughter cells. This intricate process encompasses various biological phenomena, including cytoskeleton organization and vesicle dynamics. The development of the cell plate aligns with alterations in the cytoskeleton structure and vesicles derived from the trans-Golgi, ultimately resulting in the formation of the cell plate. Nevertheless, the coordination of these processes in plants remains to be determined. Here, we introduce HYCCIN-CONTAINING2 (HYC2) as a pivotal cytoskeleton cross-linking protein that accumulates at phragmoplasts and plays a crucial role in cell plate formation and phosphatidylinositol 4-phosphate production in the plasma membrane. A genetic study involving the depletion of HYC2 postanaphase in Arabidopsis thaliana revealed the essential function of HYC2 in cell plate formation. HYC2 interacted with dynamin-related protein 1A (DRP1A) and SH3 domain-containing protein 2 (SH3P2), which are crucial for cell plate formation. In globular embryonic cells of hyc2-2/-, the recruitment of SH3P2 and DRP1A to the developing cell plate was disrupted, leading to impaired cell plate formation. Our results illuminate the role of HYC2 in the developing cell plate, possibly by directing vesicles containing SH3P2-DRP1A to the cell plate.