This study is led by Prof. Qian Qian (State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute), Prof. Deyong Ren (State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute).
Coordinated improvement of rice yield and quality has emerged as a key strategy for addressing the dual objectives of safeguarding global food security and promoting sustainable agricultural development. In modern rice breeding, a central challenge is to systematically optimize grain traits and the regulatory networks that shape them, thereby developing rice varieties that combine high and stable yield with improved nutritional and health-promoting value.
Recent advances in rice functional genomics have progressively revealed the molecular networks governing grain size, providing a rich repertoire of elite genetic targets for the directional improvement of grain weight, appearance quality, and yield potential. In parallel, beyond the major storage components of rice grains, including starch, proteins, and lipids, increasing knowledge of the genetic and metabolic mechanisms controlling essential micronutrients and health-promoting bioactive compounds has expanded the scope of rice quality improvement. Against this background, Deyong Ren et al. propose a conceptual framework for designing high-yield, high-quality rice: grain-size regulation can be harnessed to optimize yield and overall grain quality, whereas nutritional enhancement can be achieved by improving core nutrient composition and enriching functional bioactive compounds.
This review systematically synthesizes recent progress in the molecular regulation of rice grain size and nutritional quality, covering grain‑size control through key signaling pathways and multilayered regulatory mechanisms, together with nutritional quality governed by metabolic pathways of major grain components and biosynthetic routes of health‑related bioactive compounds. These advances provide a set of rational molecular targets for precision breeding and molecular design.
To address the breeding constraints imposed by gene pleiotropy and trait trade-offs, the review further outlines major strategies for acquiring and utilizing elite genetic resources. These include mining favorable alleles from landraces and wild rice germplasm, precisely modulating gene expression and function through genome editing, and integrating multiple target genes through gene pyramiding and precision design. Beyond direct food consumption, Deyong Ren et al. also highlight diversified applications enabled by grain-size and quality improvement, showing that rice can serve not only as a staple commodity but also as a breeding tool, a platform for molecular farming, and a model system for functional research.
Overall, this review proposes an integrated strategy for developing rice cultivars that combine optimized yield with enhanced nutritional quality for human health, while also supporting the creation of diversified functional rice products. More broadly, the coordinated design of yield and quality traits in rice may provide conserved genetic modules and transferable breeding strategies for the functional improvement of other cereal crops.
Science Bulletin