Importance of the cytochrome pathway of mitochondrial electron transport over the alternative pathway during the Kok effect in leaf discs of @entity3587 ( XXXX ).

@entity5121 @entity8581 @entity4626 @entity33904 @entity3587 @entity413 @entity855
The Kok effect refers to the progressive light-induced inhibition of dark respiration at low light intensities, which saturates around the light compensation point. This appears as a sudden break around the light compensation point in the plot of photosynthesis versus light intensity. The magnitude of the break can be considered as a measure of the Kok effect. In the present work, the importance of different components of dark respiration during the Kok effect was investigated by using low concentrations of mitochondrial inhibitors in leaf discs of @entity3587 ( @entity3587 . cv. Azad P1). The effects of @entity413 (stimulates respiration) and 0.8 M @entity5121 (imposes osmotic stress and inhibits photosynthesis) were also studied for comparison. The magnitude of the break decreased significantly in the presence of @entity8581 or @entity4626 (inhibitors of cytochrome pathway of mitochondrial electron transport and @entity855 synthase, respectively). In contrast, there was no significant change with @entity33904 ( @entity33904 ; an inhibitor of alternative pathway of mitochondrial electron transport). The magnitude of the break increased significantly with @entity413 , and decreased on exposure to osmotic stress. Our results suggest that the Kok effect (inhibition of dark respiration in light) is modulated by inhibitors of cytochrome pathway and @entity855 synthesis, but not that of the alternative pathway.
