Even though plants cells photosynthesize, they still use their mitochondria for oxidation of pyruvate. when and where will this occur?

Mitochondria are active almost throughout in the plant, unlike chloroplast that is present in some parts of the plants such as the leaves and active only in the presence of sunlight. Mitochondria, through respiration, powers plant biological processes such as active uptake of ions in the roots and transport in the plasmodesmata.