Action Spectrum for Photoactivation of the Water‐splitting System in Plastids of Intermittently Illuminated Wheat Leaves

Publisher Website
Google Scholar
Abstract
The chloroplasts from wheat leaves developed under intermittent illumination (1 ms light + 12 min dark) were able to photoreduce DPIP with DPC as electron donor but unable to photoreduce DPIP with water as electron donor. On exposure of these leaves to continuous light, the Hill activity with water as electron donor was rapidly induced. The photoactivation was sensitive to the treatment with DCMU prior to exposure to continuous light. The action spectrum for the photoactivation showed a sharp band at 680 nm with a distinct shoulder at 650 nm, and was similar to the absorption spectrum of photosytem‐2 particles. These data suggest that the electron transfer driven by photosystem 2 is essential for the activation of the water‐splitting system in the chloroplasts of intermittently illuminated leaves.