Where does the Calvin cycle occur in C4 plants?

The Calvin cycle in C4 plants occurs in the bundle-sheath cells. This is a key feature of C4 photosynthesis, which is an adaptation to help plants minimize water loss and increase efficiency in hot environments.

In C4 plants, photosynthesis is divided into two distinct stages: the initial carbon fixation occurs in the mesophyll cells, where carbon dioxide is first incorporated into a four-carbon compound (hence the name C4). Subsequently, this four-carbon compound is transported to the bundle-sheath cells, where it is converted back to carbon dioxide and enters the Calvin cycle. This spatial separation allows C4 plants to effectively concentrate carbon dioxide for the Calvin cycle, reducing photorespiration and enhancing sugar production under conditions where C3 plants would struggle.

This unique arrangement allows C4 plants to thrive in environments with high temperatures and light intensity, which can be particularly beneficial for their survival and productivity.