Yes, CAM plants do use Rubisco.
CAM (Crassulacean Acid Metabolism) plants utilize Rubisco in the second step of their carbon fixation process. While they initially fix CO2 using PEP carboxylase (PEPCase) at night, storing it as malic acid, they subsequently decarboxylate this malic acid during the day, releasing CO2. This released CO2 is then concentrated around Rubisco, allowing for efficient carbon fixation in the Calvin cycle. Therefore, Rubisco is essential for the ultimate conversion of CO2 into sugars in CAM plants.
In short, CAM plants employ a two-step carbon fixation process to minimize water loss in arid environments. This process relies on both PEPCase for initial CO2 capture and Rubisco for the final carbon fixation step within the Calvin cycle.
