Figure 1. Transporters in the lichen symbiosis.

Left: cross-section of a lichen thallus with both cyanobacterial and algal photobionts. Left: The cephalodium is a structure that houses the cyanobacterial cells. The cyanobacterial vegetative cells are shown in green, and the heterocysts are shown in white. “Tomentum” refers to the fungal area composed of closely matted mycelia. Right: Detail of symbiotic interface showing interaction of fungal cells with photosynthetic cells. Transporter activities that do not have an identified transporter are indicated with a question mark. Red transporter, C transporter (glucose or polyols such as ribitol); blue transporter, N transporter (ammonium).