Photorespiration : It is light dependent process of oxygenation of ribulose biphosphate (RuBP) and release of carbon dioxide by the photosynthetic organs of a plant. 

The photorespiratory losses are checked by sugarcane by having physiological adaptations The process of photosynthesis occurs in mesophyll cells and bundle sheath cells.

Mesophyll cells : 

(i) Initially, CO₂ in taken up by phosphoenol pyruvate (PEP) and changed to oxaloacetate (OAA) in the presence of PEP carboxylase (PEPCO).

(ii) Oxaloacetate is reduced to malate/aspartate, the product formed reach into bundle sheath.

Bundle Sheath : 

(i) The oxidation of malate (an aspartate) occurs with release of carbon dioxide and formation of pyruvate (3C). 

(ii) Due to increased CO₂ concentration, the RuBisco function as carboxylase and not as oxygenase. 

(iii) This prevents the photosynthetic losses. 

(iv) RuBP operates now under Calvin cycle and pyruvates transported back to mesophyll cells changed into phosphoenol pyruvate, to keep the cycle going.