Figure 3.

In planta self-interaction assays of PLRV P3a shows that tag orientation influences subcellular localization of the P3a homodimer. Panels represent single-plane confocal micrographs of N. benthamiana leaf epidermal cells co-expressing bimolecular fluorescence complementation (BiFC) fragments (nYFP and cYFP) fused to the (A) C-terminus; (B) the N-terminus of P3a; or (C) the C-terminus of the PLRV P17 movement protein. The fluorescence signal from the reconstitution of YFP due to self-interaction of the viral proteins is false-colored yellow. Negative controls are represented in the right two micrographs with (A) co-expression of the P3a N-terminal BiFC fusions with monomeric red fluorescent protein (mRFP, red fluorescence) fused to the complementary tag and (B,C) co-expression of the viral C-terminal BiFC fusion proteins with their complimentary empty vector tag. The overlay of the bright field images are shown in the column marked “Overlay” and in negative control images with chloroplast autofluorescence falsely colored blue. Fluorescent protein detection in the nuclei (white asterisks), aggregates (white arrows), and chloroplasts (white arrow heads) are highlighted. Scale bars represent the length indicated in micrometers (μm).