Rice MGD1-Mediated Improvement of Photosynthesis and Crop Yield by Flexible Adaptation to Different Light Conditions

Flexible adaptation to different light intensities found in natural environments is crucial for efficient photosynthesis and yield production in crops. The ability to cope with suboptimal light conditions effectively and efficiently is clearly advantageous. In this study, increased photosynthetic ability, biomass accumulation, grain yield and high membrane lipid contents were observed in OsMGD1-overexpression plants of rice and tobacco under both low and high light conditions. Further exploration of the photosynthetic performance and xanthophyll cycle-dependent photoprotection in these transgenic plants revealed that under low light conditions, the overexpression lines maintained high levels of chlorophyll content and light harvesting capability, leading to a high photosynthetic quantum yield. While under high light conditions, the de-epoxidation status of xanthophyll cycle pigments was higher in the overexpression plants, leading to sufficient photoprotection and reduced photo-oxidative damage, resulting in an increased electron transport rate. These results indicate that OsMGD1 is involved in regulating photosynthetic processes when plants are exposed to different light intensities, providing an effective strategy for achieving improved photosynthesis and crop production under variable light conditions in nature.