Fig. 4.

Different combinations of wavelengths (serial or simultaneous) have synergistic and/or interfering effects on the observed light-dependent increases in NO. Individual exposures were of $2.88\pm 0.06\mathrm{J}/{\mathrm{cm}}^2$ at $800\pm 17.9\mu \mathrm{W}/{\mathrm{cm}}^2$ for each wavelength; serial exposures (denoted: first wavelength and second wavelength) were $1.44\pm 0.03\mathrm{J}/{\mathrm{cm}}^2$ ($800\pm 17.9\mu \mathrm{W}/{\mathrm{cm}}^2$ for 30 min) for one wavelength, followed by $1.44\pm 0.03\mathrm{J}/{\mathrm{cm}}^2$ ($800\pm 17.9\mu \mathrm{W}/{\mathrm{cm}}^2$ for 30 min) of the other wavelength (total $2.88\pm 0.06\mathrm{J}/{\mathrm{cm}}^2$); simultaneous exposures (denoted: combo wavelength 1 + wavelength 2) were $1.44\pm 0.03\mathrm{J}/{\mathrm{cm}}^2$ of each wavelength, both at $400\pm 8.9\mu \mathrm{W}/{\mathrm{cm}}^2$, simultaneously for 60 min (total $2.88\pm 0.06\mathrm{J}/{\mathrm{cm}}^2$). Immediate postexposure percent changes in NO level ($\mathrm{\Delta }f/f$ DAF-FM fluorescence) ± standard error for (a) 635-nm red, 532-nm green, and combinations of the two; (b) 635-nm red, 808-nm near-infrared, and combinations of the two; (c) 635-nm red, 447-nm blue, and combinations of the two; (d) 808-nm NIR, 447-nm blue, and combinations of the two (635-nm red is included as a common point of reference); and (e) all of the above wavelengths, in order of percent change.