Figure 2.

Exposure to pyoverdine damages host mitochondria. (A, B) Visualization of a Peredox fluorescence reporter bound to NADH, normalized to a constitutively-expressed, RFP-tagged protein (A) or GFP fluorescence from a PINK-1::GFP reporter, normalized to a constitutively-expressed, RFP-tagged protein (B). Worms were exposed to pyoverdine-rich or pvdA filtrate, pyoverdine-rich filtrate saturated with iron, or media. (C, D) Quantification of fluorescence for the conditions above. At least 150 worms were analyzed for each biological replicate (approximately 50 worms per image). (E) Relative quantification of mitochondrial:nuclear genome copy number in worms exposed to pyoverdine-rich filtrate or filtrate from PA14pvdA (control). (F) Fluorescence of the mtRosella reporter in worms treated with wild-type filtrate or wild-type filtrate pre-saturated iron. The GFP signal is sensitive to low pH, and loses fluorescence within autophagolysosomes. (G) Bioluminescence of a GFP-tagged luciferase in C. elegans exposed to pyoverdine-rich filtrate or media control. Light and GFP fluorescence were measured 1 hour after the addition of luciferin. Luminescence was normalized to GFP fluorescence to control for differences in protein expression. Data presented in A, B, F, and G are one representative result from four biological replicates. Data presented in E are the average from three biological replicates. Error bars in C, D, E, G represent SEM. Asterisks indicate p-value < 0.01, hashes are p < 0.05, based on Student's t-test.