Autophagy is an evolutionarily conserved quality control pathway essential for plant growth and development, as well as stress response. During the autophagic response, a double-membraned organelle termed an autophagosome is formed from the endoplasmic reticulum (ER) to engulf and deliver undesirable cytoplasmic contents into the lytic vacuole for degradation. Autophagy-related proteins and phosphoinositides regulate autophagic response and autophagosome biogenesis. In yeast and mammalian cells, oxysterol-binding protein-related proteins (ORPs) are a family of lipid transfer proteins (LTPs) that structurally establish membrane contact sites (MCSs) and transfer lipids between membranes in a non-vesicular manner. We have recently demonstrated that the Arabidopsis ORP2A (AtORP2A) is localized to putative ER–plasma membrane (PM) contact sites (EPCSs) and ER–autophagosomal membrane contact sites (EACSs), and that AtOPP2A regulates phosphatidylinositol 3-phosphate (PI3P) distribution at the EACSs for autophagosome formation. It has been reported that phosphatidylinositol 4-phosphate (PI4P) in the PM regulates autophagosome biogenesis in Arabidopsis. We thus hypothesize that AtORP2A structurally mediates the formation of EPCSs and functionally transfers PI4P from the PM to the ER for mediating autophagosome formation in Arabidopsis. The current study aims to (1) examine the ultrastructure of ORP2A–positive EPCSs; (2) investigate the lipid transfer ability of ORP2A in vitro and in vivo; and (3) elucidate the role of PI4P in EPCS formation and autophagosome biogenesis in Arabidopsis. Here we will present our preliminary findings in this study.