Mitochondrially targeted eqFP611 and smGFP4 expressed from the same plasmid. Transfection of N. tabacum wild-type protoplasts with a construct encoding both eqFP611 and smGFP4 with mitochondrial presequences (pIVD144-eqFP611-IVD145-smGFP4). Pictures of the same cell, taken through MitoTracker (A) or FITC (B) filter sets, respectively. Scale bars: 10 μm. (C) Plasmid used for transfection. Black arrow, CaMV 35S: cauliflower mosaic virus 35S promoter; grey boxes, IVD(144)/(145): N-terminal 145 and 144 nucleotides of the IVD coding sequence, respectively; red box, eqFP611: eqFP611 coding sequence; green box, smGFP4: smGFP4 coding sequence; black box, NOS T: nopaline synthase terminator; white box, S: spacer sequence. H: HindIII, Sa: SacI, Sm: SmaI, Xh: XhoI, Xb: XbaI, P: PstI, B: BamHI, E: EcoRI restriction sites. Vector backbone: pUC19.