BiFC interactions of RAB8A with either RTNLB2, 3, 4 or RTNLB8 in transiently transfected wild-type Arabidopsis leaf protoplasts. Protoplasts were transfected with plasmids encoding cEYFP-RAB8A or nEYFP-RTNLBs, and with the pBIN20-Golgi-CFP plasmid (to mark the Golgi apparatus of transfected cells) (Panel A), or the pBIN20-ER-mCherry plasmid (to mark the ER of transfected cells) (Panel B). The protoplasts were imaged by a laser scanning confocal microscope with a multi-track channel mode after transfection. Labels above first set of panels indicates the filter set/channel imaged. DIC, differential interference contrast image. Cyan indicates CFP fluorescence; yellow indicates BiFC YFP fluorescence; red indicates mCherry fluorescence; merge indicates overlaid images of CFP and YFP signals, or of mCherry and YFP signals. The nEYFP-RAB8A (Panel A-1, B-1) or the cEYFP-RAB8A (Panel A-2, B-2) did not show interaction with the cEYFP-or nEYFP-empty vectors. The nEYFP-RTNLB2 (Panel A-3, B-3), -RTNLB3 (Panel A-4, B-4), -RTNLB4 (Panel A-5, B-5), -RTNLB8 (Panel A-6, B-6) showed interaction with cEYFP-RAB8A in the plant cells and YFP signals overlaid with the CFP-Golgi signals (Panel A) and the mCherry-ER signals (Panel B). Yellow bar = 20 um.