Unraveling the Secrets of Efficient Photosynthesis: A Path to Climate-Resilient Crops

**More than three billion years ago, ancient bacteria first started the process of photosynthesis. Over millennia, this ability evolved, leading to the emergence of two types of photosynthesis: C3 and C4. While the majority of plants, including rice, use C3 photosynthesis, a more efficient form called C4 evolved in species such as corn and sorghum.** C4 plants are particularly suited to hot, dry environments, largely due to their enhanced efficiency and resilience against drought and heat. **Scientists have long pondered the possibility of engineering C3 plants to use C4 photosynthesis.** **In a breakthrough study, researchers from Salk and University of Cambridge utilized single-cell genomics technology to discover that the difference between C3 and C4 photosynthesis is not due to new or missing genes but involves regulatory changes.** Specifically, they found that both C3 and C4 plants contain the same genetic materials, but the activation of these genes is managed differently, mostly through transcription factors known as DOFs. In C4 plants, regulatory elements associated with photosynthesis are triggered by DOFs, facilitating efficient photosynthesis. This discovery opens up the potential for modifying C3 plants, such as rice or wheat, to exploit the benefits of C4 photosynthesis. Although transforming C3 crops into C4 is a long-term goal with technical challenges, the results of this study are a significant step forward. This research is part of broader efforts like the "C4 Rice Project" and the Salk Harnessing Plants Initiative, aiming to create crops better suited for future climatic conditions. The findings have been made available as a comprehensive resource for researchers globally.**