Rubisco degradation: A new target for crop improvement

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is the most abundant leaf protein and a central enzyme in photosynthesis, playing a critical role in carbon fixation, nitrogen allocation, and stress responses. This review comprehensively examines the structural characteristics and physiological functions of Rubisco, with a primary focus on the diverse mechanisms governing its degradation. We detail the proteolytic pathways operating within the chloroplast and the vacuole-dependent routes, including autophagy, the SAV (stress-associated vacuole) pathway, the CV (Rubisco-containing vesicle) pathway, and degradation via vacuolar membrane rupture. The key proteases involved in these processes and their specific functions are also elucidated. Building on this mechanistic foundation, we explore the potential applications of manipulating Rubisco degradation for crop improvement, such as enhancing stress resilience, optimizing yield, and improving nutrient use efficiency. Ultimately, this review provides a theoretical framework and practical strategies for developing high-efficiency, high-quality crop varieties through the targeted regulation of Rubisco protein turnover.