Figure 2

Overexpression of AtUCP1 in tobacco induces mitochondrial biogenesis through retrograde signaling. (A) Five leaves, from youngest (L1) to oldest (L5), were sampled from WT and transgenic lines P49 and P07. (B and C) Mesophyll protoplasts isolated from WT (B) and P07 (C) L3 leaves stained with MitoTracker Red. The panels are representative of 50 protoplasts evaluated for each genotype. Scale bars = 5 μm. (D) Quantification of the MitoTracker Red signal in a population of protoplasts isolated from the L3 leaves of WT and transgenic lines P49 and P07 (n = 50). (E) Relative mtDNA content of WT and transgenic lines P49 and P07 in leaves L1 to L5. (F) Relative mRNA content of genes involved in targeting proteins to mitochondria (GRPe chaperone) and energy metabolism (NADH-DeH, NADH-IS2, and NADH-IS7) in L1 leaves of WT and transgenic lines P49 and P07. (G) Immunoblot analysis of nuclear- (IDH, VDAC and AOX) and mitochondrial-encoded (COXII) proteins involved in energy metabolism, transport, and stress response in the L1 leaves of WT and transgenic line P07. The data presented in panels E and F are representative of four biological replicates (n = 4). *p < 0.05 and **p < 0.1 compared with WT. Error bars, mean ± s.e.m.