How C4 plants are capable of photosynthesis with no apparent photorespiration?

Oxygen evolving site is different from the site where RuBisCO is present.Light reactions, during which oxygen is evolved, operate in chloroplasts of mesophyll cells. RuBisCO is present only in stroma of those chloroplasts which are found in bundle sheath cells where Calvin cycle is operational. Bundle sheath cells have thick walls impervious to gaseous exchange and no intercellular spaces. Therefore, no exchange of oxygen gas takes place between mesophyll and bundle sheath cells. As a result, C4 plants are capable of photosynthesis with no apparent photorespiration.