New insights into hybrid rice grain quality: How LY287 achieves superior performance

Using integrated metabolomics and transcriptomics, the team found that LY287 initiates starch biosynthesis earlier than its parental lines, leading to enhanced grain filling and quality. This study highlights the crucial role of early metabolic activity and the regulation of starch metabolism by the ABA-SLRL2-Wx1 pathway.

Rice (Oryza sativa L.), a staple food for more than half of the global population, has long been the focus of agricultural research aimed at improving both yield and quality. Hybrid rice, which harnesses heterosis, has been particularly successful in boosting rice productivity. However, the molecular mechanisms underlying the superior grain quality of hybrid rice, especially during the crucial grain filling process, remain not fully understood. Grain filling is vital for determining the rice grain's weight and quality, as it involves the accumulation of starch, proteins, and other essential nutrients. Starch synthesis, regulated by enzymes and transcription factors, plays a central role in determining rice grain quality, with variations in amylose content and starch structure affecting cooking characteristics and flavor.

A study (DOI: 10.48130/seedbio-0025-0024) published in Seed Biology on 24 December 2025 by Pingfang Yang’s team, Hubei University, provides valuable insights into the molecular mechanisms underlying the superior grain quality of hybrid rice LY287, highlighting the early initiation of starch biosynthesis and the regulation of key metabolic pathways that enhance grain filling and quality.

A metabolomic and transcriptomic analysis was conducted to investigate the grain quality of hybrid rice LY287, an early-season cultivar known for its superior grain quality. The study compared the rice grains of LY287 with its male parent, F7M, at three stages of development: 10, 15, and 20 days after pollination (DAP). Metabolomic data revealed that LY287 exhibited a more compact and larger starch crystal structure in the endosperm, contributing to its enhanced grain quality. Significant differences in grain quality parameters were found between LY287 and F7M, including head rice percentage, chalkiness degree, and amylose content. Metabolite analysis identified 1,169 differentially accumulated metabolites, with peak metabolite abundance occurring early in the grain filling process. The metabolite profile showed that metabolites related to amino acids, organic acids, and lipids were abundant early on, while nucleic acids decreased as development progressed. Transcriptomic analysis indicated that genes associated with starch and sucrose metabolism were activated earlier in LY287 than in F7M, contributing to an accelerated grain filling process. Notably, the ABA-SLRL2-Wx1 pathway was found to play a key role in regulating starch synthesis, with LY287 exhibiting higher ABA content and more efficient regulation of starch synthesis genes than its parental line. This early onset of starch biosynthesis, coupled with the regulation of amylose content, suggests that LY287’s superior grain quality is a result of rapid storage compound accumulation during the early stages of development, making it an ideal candidate for breeding programs aimed at improving hybrid rice quality.

This study represents a significant step forward in understanding the molecular mechanisms underlying the grain filling process in hybrid rice. By elucidating the role of early starch biosynthesis and ABA regulation in LY287, it offers a promising avenue for improving the quality of hybrid rice varieties. As global food security and rice quality remain pressing concerns, these insights provide a foundation for future breeding efforts aimed at optimizing both the yield and quality of rice crops worldwide.

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References

DOI

10.48130/seedbio-0025-0024

Original Source URL

https://doi.org/10.48130/seedbio-0025-0024

Funding information

This work was supported by the Hubei Provincial Key Research and Development Projects (Grant No. 2024BBB001), the Natural Science Foundation of Hubei Province (Grant No. 2023AFA016), Open Project Funding of the Key Laboratory of Evaluation and Utilization of Grain Crop Genetic Resources, Ministry of Agriculture and Rural Affairs (Grant No. SAGC-2023001), and Hubei Provincial Natural Science Foundation of China (Grant No. 2023AFB614).

About Seed Biology

Seed Biology (e-ISSN 2834-5495) is published by Maximum Academic Press in partnership with Yazhou Bay Seed Laboratory. Seed Biology is an open access, online-only journal focusing on research related to all aspects of the biology of seeds, including but not limited to: evolution of seeds; developmental processes including sporogenesis and gametogenesis, pollination and fertilization; apomixis and artificial seed technologies; regulation and manipulation of seed yield; nutrition and health-related quality of the endosperm, cotyledons, and the seed coat; seed dormancy and germination; seed interactions with the biotic and abiotic environment; and roles of seeds in fruit development. Seed biology publishes a wide range of research approaches, such as omics, genetics, biotechnology, genome editing, cellular and molecular biology, physiology, and environmental biology. Seed Biology publishes high-quality original research, reviews, perspectives, and opinions in open access mode, promoting fast submission, review, and dissemination freely to the global research community.