Mechanisms to avoid photoinhibition in a desiccation-tolerant cyanobacterium, Nostoc commune

A desiccation-tolerant cyanobacterium, Nostoc commune, shows unique responses to dehydration. These responses are: (i) loss of PSII activity in parallel with the loss of photosynthesis; (ii) loss of PSI activity; and (iii) dissipation of light energy absorbed by pigmentprotein complexes. In this study, the deactivation of PSII is shown to be important in avoiding photoinhibition when the CalvinBenson cycle is repressed by dehydration. Furthermore, our evidence suggests that dissipation of light energy absorbed by PSII blocks photoinhibition under strong light in dehydrated states.