Advances in photosynthesis research: Unlocking the potential for food security, renewable energy, and environmental sustainability

Abstract

Photosynthesis is the most important biochemical process and the largest-scale process of matter and energy conversion on Earth. It is the process by which plants, algae, and certain bacteria convert light energy into chemical energy. Through photosynthesis, solar energy is used to transform carbon dioxide and water into organic matter (such as glucose) and oxygen. This process not only provides energy and growth materials for plants themselves, but also supplies food and oxygen for other organisms in the ecosystems. The organic matter accumulated by crops through photosynthesis is the primary source of food for humans and animals. Improving photosynthetic efficiency can directly increase crop yields, helping to address the pressure of global population growth on food demand. Photosynthesis is also a core component of the Earth's carbon cycle, helping to maintain the balance of carbon dioxide and oxygen in the atmosphere and mitigating the effects of the greenhouse effect. Research on photosynthesis has also inspired the development of renewable energy. By mimicking the mechanisms of photosynthesis to design artificial photosynthetic systems, solar energy can be converted into clean energy for human beings. Focusing on photosynthesis research can help solve human challenges related to food, energy, and the environment. In recent years, extensive research has been conducted on the essence of energy absorption, transfer, and conversion in photosynthesis, yielding fruitful results. This special issue on photosynthesis research includes 10 articles, comprising three reviews, five research papers, and two commentaries.

Chloroplasts are the sites where photosynthesis occurs, and chloroplast biogenesis is a prerequisite for the smooth progression of photosynthesis. Frangedakis et al. (2024) explored the novel roles of MpRR-MYB2 and MpRR-MYB5 in chloroplast biogenesis, revealing their interactions with GOLDEN-LIKE (GLK) and GATA transcription factors. Kushwaha et al. (2025) commented on this research, noting that these MYB transcription factors not only regulate chloroplast development but also influence the expression of genes related to photosynthesis, photorespiration, and carbon fixation. Although MYB and GLK have synergistic roles in chloroplast biogenesis, MYB cannot fully replace GLK's functions. The commentary also pointed out that MYB transcription factors play a significant role in the development of male reproductive organs in plants. Future research should further explore the epigenetic regulation of MYB genes and their roles in stress responses, providing new insight for improving crop photosynthetic efficiency and yield. As semi-autonomous organelles, nearly 3,000 proteins in chloroplasts are transported from the cytoplasm. In this special issue, Xing et al. (2025) reviewed the latest advances in chloroplast protein import complexes (the outer chloroplast (TOC)–the inner chloroplast (TIC)) and their regulatory mechanisms. They detailed the structure and function of TOC and TIC complexes and their roles in chloroplast protein import, particularly new models revealed through cryo-electron microscopy. Although the composition of the TOC complex is relatively conserved, the composition of the TIC complex and its associated motor proteins remains controversial, with some components (such as Tic110 and Tic40) from traditional models not supported by recent studies. The article also discussed the quality control and retrograde signaling mechanisms of chloroplast protein import, emphasizing the important role of the ubiquitin-proteasome system in regulating protein import. Additionally, future research directions were proposed, including exploring the structural and functional differences of TOC–TIC complexes in different species and the impact of protein folding states on import pathways. This review provides critical insight into the molecular mechanisms of chloroplast protein import and lays the foundation for further research in related fields. Chlorophyll plays a crucial role in photoelectric conversion. Li et al. (2025) comprehensively reviewed the regulation of chlorophyll biosynthesis pathways and retrograde signaling networks, highlighting chlorophyll's central role in photosynthesis and its importance in plant development and environmental responses. They detailed the enzymatic regulation, transcriptional and post-translational modifications of chlorophyll synthesis, as well as the retrograde signaling mechanisms between chloroplasts and the nucleus. By integrating the latest research findings, they demonstrated the complexity and diversity of chlorophyll metabolism and pointed out its potential applications in synthetic biology and agriculture. This review provides in-depth insight into the regulatory mechanisms of chlorophyll biosynthesis and lays a solid foundation for future research and applications.

The key first step in achieving efficient energy absorption, transfer, and conversion in photosynthesis is the light-harvesting process. In recent years, significant progress has been made in understanding the light-harvesting complexes of photosynthetic organisms through structural biology. Huang et al. (2025) reported the structure of the smallest reaction center–light-harvesting complex (CaRC–LH) in the photosynthetic bacterium Chloroflexus aurantiacus, resolved using cryo-electron microscopy at a resolution of 3.05 Å. This complex consists of only seven light-harvesting subunits, forming a crescent shape around the mobile quinone-binding site of the reaction center. The study revealed the detailed organization and cofactor arrangement of this minimal light-harvesting complex, explaining why this bacterium requires an additional light-harvesting antenna—the chlorosome—to ensure sufficient light capture. The article also explored the electron transfer pathways and the binding mechanisms between the complex and the chlorosome, providing new insight into the diversity of light capture and energy transfer in photosynthesis. This discovery not only sheds light on the evolutionary adaptability of photosynthetic bacteria, but also offers important references for research on photosynthetic mechanisms.

Photosynthetic carbon fixation is a critical step in converting unstable chemical energy into stable chemical energy. In addition to the C₃, C₄, and CAM carbon fixation types, there are diverse carbon fixation mechanisms in nature. Recently, Liu et al. (2024) published the genome of Eleocharis vivipara, revealing the unique mechanism by which this amphibious plant uses C₃ and C₄ photosynthesis for carbon fixation underwater and on land, respectively. Besnard (2025) commented on this achievement, noting that this photosynthetic plasticity might have been acquired through hybridization or polyploidization events, with genomic recombination and epigenetic regulation playing key roles in its C₃–C₄ transition. Although the study provided important genomic and transcriptomic resources, some questions remain unresolved, such as the origin and evolutionary history of C₄ photosynthesis genes. Future phylogenomic studies are expected to further elucidate these mechanisms and offer potential applications for crop improvement. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is the most abundant enzyme on Earth and directly determines the efficiency of photosynthesis. However, as a key enzyme in photosynthesis, its inefficiency and sensitivity to oxygen limit plant carbon fixation efficiency. Qin et al. (2025) comprehensively discussed the progress and challenges in plant carbon assimilation engineering, particularly focusing on optimizing RuBisCO and developing novel carbon fixation pathways. The authors detailed strategies such as directed evolution, rational design, chimeric enzymes, and cofactor engineering to improve RuBisCO's catalytic efficiency. Additionally, the article discussed the use of microcompartments (such as carboxysomes and bundle-sheath cells in C₄ plants) to increase CO₂ concentration and reduce photorespiratory losses. Although some success has been achieved in laboratory and model organisms, implementing these engineered pathways in higher plants has remained challenging. This review demonstrates that, through synthetic biology and artificial intelligence, it is possible to significantly improve crop yields and photosynthetic efficiency in the future, offering solutions to global climate change and food security. The oxygenase activity of RuBisCO also limits its efficient carbon fixation. Mo et al. (2025) successfully improved photosynthetic carbon fixation efficiency and panicle structure in rice by engineering a photorespiration-dependent glycine betaine (GB) biosynthesis pathway. The research team introduced a glycine methylation pathway (imGS) from halophilic cyanobacteria into rice mitochondria, converting glycine produced during photorespiration into GB while reducing the levels of photorespiratory intermediates, thereby decreasing carbon loss from photorespiration and increasing photosynthetic rates and carbohydrate accumulation. Additionally, imGS rice showed improved panicle structure, with significantly increased branch and grain numbers, although the seed-setting rate and thousand-grain weight decreased. This study provides a new strategy for enhancing crop photosynthetic efficiency and yield through mitochondrial photorespiration bypass, with significant application potential.

Photosynthetic organisms employ various strategies to cope with environmental stresses to ensure the smooth progression of photosynthesis. In this special issue, Feng et al. (2025) used cryo-electron microscopy to resolve the structure of the PSI–FCPI (photosystem I–fucoxanthin chlorophyll a/c-binding protein Is) supercomplex in Thalassiosira pseudonana (Tp) under high-light conditions, revealing the light adaptation strategies of diatoms in high-light environments. They found that Tp–PSI–FCPI reduced the number of peripheral FCPI under high light to avoid photodamage, while retaining five stable FCPI subunits rich in diadinoxanthin (Ddx)/diatoxanthin (Dtx), which may be involved in energy dissipation. The article also proposed the assembly mechanism of PSI–FCPI, emphasizing the key roles of Tp-FCP3 and Tp-Lhcr3 in stabilizing FCPI binding. These findings provide new insight into how diatoms adapt to fluctuating light intensities in marine environments and reveal the unique evolutionary strategies of diatom photosynthetic systems. Ali et al. (2025) studied the antagonistic regulatory mechanisms of VvHY5 and VvBEE1 on resveratrol (Res) biosynthesis in grapevine (Vitis vinifera L.) under high light stress. The study found that high-light-induced VvHY5 activated the expression of stilbene synthase genes (VvSTS), promoting Res accumulation and alleviating photoinhibition and oxidative damage. In contrast, VvBEE1 inhibited Res synthesis by competing with VvHY5 for binding to the VvSTS promoter, exacerbating photodamage. The research also revealed the interaction between light signaling and brassinosteroid (BR) signaling under high light stress, indicating that the antagonistic roles of VvHY5 and VvBEE1 play a key role in regulating grapevine photoprotection mechanisms. These findings provide new insight into how plants cope with high light stress and offer potential strategies for improving crop stress tolerance. Cao et al. (2025) studied the regulatory mechanism of the FaNAC047–FaNAC058 module in heat stress-induced leaf senescence in tall fescue (Festuca arundinacea). The study found that FaNAC047 directly activated chlorophyll degradation genes (FaNYC1, FaNOL, FaSGR) and inhibited catalase gene (FaCAT2) expression, promoting chlorophyll degradation and reactive oxygen species (ROS) accumulation, thereby accelerating heat-induced leaf senescence. Additionally, FaNAC047 forms a protein complex with FaNAC058, further enhancing the regulation of downstream genes. This study reveals the critical role of the FaNAC047–FaNAC058 module in heat stress-induced leaf senescence and provides new genetic resources for breeding heat-tolerant plants.

Photosynthesis research will continue to make breakthroughs in multiple fields, driving advancements in agriculture, ecology, and renewable energy. First, with the progress of synthetic biology and gene-editing technologies, researchers can more precisely engineer photosynthetic pathways to optimize light energy utilization efficiency and carbon fixation capacity. For example, by introducing artificial photorespiration bypasses or enhancing RuBisCO activity, it is possible to significantly improve crop photosynthetic efficiency and yield, addressing global food security challenges. Second, photosynthesis research will help to understand how plants respond to environmental stresses such as high temperatures, drought, and salinity. By uncovering the photosynthetic regulatory mechanisms under various stresses, more stress-resistant crop varieties can be developed, enhancing agricultural sustainability. Additionally, photosynthesis research will provide new ideas for renewable energy development. Artificial photosynthetic systems aim to mimic natural photosynthesis, efficiently converting solar energy into hydrogen or other clean fuels. Such technologies have the potential to become important alternatives to fossil fuels, reducing greenhouse gas emissions and mitigating climate change. Finally, fundamental research on photosynthesis will deepen our understanding of the origin and evolution of life. By comparing photosynthetic mechanisms across different organisms, the evolutionary history of photosynthesis and its critical role in life evolution can be revealed. In summary, photosynthesis research has broad application prospects in agriculture, ecology, and energy, providing essential support for the sustainable development of human society.