Figure 11.

Structural diversity in PD and their constituents. A, A cartoon depiction of a simple plasmodesma showing details of the PM, lipid composition, and select protein constituents as described in the text. B, Cartoons depicting some PD morphologies. (1) is a branched PD with a “Y” shape, (2) represents a simple pore with constrictions near the openings (necks) and dilation of the central region of the DT, (3) is a funnel plasmodesma. A and B were drawn with BioRender. C and D, Structure of branched PD in Arabidopsis leaf tissue revealed by ET. C, Four representative individual frames from a tomogram (1/4–4/4). While the PM is readily visible in these images, the DT is difficult to discern. Central cavities are found in the vicinity of the middle lamella. D, 3D model of PD generated by tracing the inner (yellow) and outer (blue) leaflets of the PM in the tomogram in (C). The PD on the left consists of two pores in Cell 2 and one in Cell 1. The PD on the left has two openings to Cell 2 but three to Cell 1. Ribosomes (red) are shown for scale. C and D were generated in the author’s lab.