NAP1 colocalizes with the ER marker GFP-HDEL in ER bodies and/or reticulate structures in leaf pavement cells and mesophyll cells. Wild-type cells expressing transgenic GFP-HDEL (middle) were labeled with anti-NAP1 antibody that was detected with an Alexa546-conjugated secondary antibody (left). Right, Overlay images of the two channels. A, In pavement cells, NAP1 colocalizes with GFP-HDEL-positive ER cisternae, ER tubules, and ER bodies. The arrows point to ER bodies that contain both GFP-HDEL and NAP1. B, In pavement cells, punctate NAP1 signals do not completely overlap with GFP-HDEL but, instead, are either adjacent to GFP-HDEL-labeled ER or in seemingly independent structures. Right, The inset image is the enlarged boxed region in the same panel. The arrows indicate NAP1 punctae that are in physical contact with GFP-HDEL-labeled ER. The arrowheads indicate NAP1 punctae that were not associated with the GFP-HDEL ER. C, NAP1 colocalizes with GFP-HDEL in mesophyll cells. Bars = 5 μm in A, 10 μm in B and C, and 5 μm in the inset in B.