J Integr Plant Biol

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  • 收稿日期:2025-06-04 接受日期:2026-08-05

The miR1866–OsUBP7 regulatory module promotes grain yield and seed dormancy through abscisic acid signaling in rice

Yafan Zhao1, Yuan Li1, Zongrun Li1, Kai Du1, Gaohui Li1, Yuman Jin1,2, Jialu Li1, Xiaofan Zhang3, Guiliang Tang4, Ye Liu1, Jing Zhang1, Quanzhi Zhao5, Hongwei Xue6*, Ting Peng1*   

  1. 1. Collaborative Innovation Center of Henan Grain Crops, Henan Key Laboratory of Rice Molecular Breeding and High Efficiency Production, Henan Center of Crop Genomics and Rice Engineering, Henan Agricultural University, Zhengzhou 450046, China
    2. Xinxiang Academy of Agricultural Sciences, Xinxiang 453004, China
    3. Shanghai University of Medicine & Health Sciences, Shanghai 201318, China
    4. Department of Biological Sciences, Michigan Technological University, Houghton MI 49931, USA
    5. College of Agriculture, Guizhou University, Guiyang 550025, China
    6. South China Agricultural University, Guangzhou 510642, China
    *Correspondences: Ting Peng (lypengting@163.com, Dr. Peng is fully responsible for the distribution of all materials associated with this article); Hongwei Xue (xhw@scau.edu.cn)
  • Received:2025-06-04 Accepted:2026-08-05
  • Supported by:
    This research was supported by the National Natural Science Foundation of China (32001440 and 32272014), the Natural Science Foundation of Henan (262300421249), and the Henan University Innovative Research Team Program in Science and Technology (25IRTSTHN030). Additional support came from the Science and Technology Innovation Foundation of Henan Agricultural University (2024CXZX006) and a Henan Provincial Science and Technology Research Project (252102111144). The Key Laboratory of Functional Agriculture of Guizhou Province ([2023]007) and the Key Laboratory of Molecular Breeding for Grain and Oil Crops of Guizhou Province ([2023]008) also supported this work.

Abstract: Higher grain weight and stronger seed dormancy are key objectives for improving rice (Oryza sativa) yield and inhibiting pre-harvest sprouting. Therefore, identifying genes that coordinately regulate grain weight and seed dormancy is an urgent priority. Here, we report that knocking out miR1866 (KO1866) increased grain weight and reinforced dormancy. We identified the transcript of ubiquitin-specific processing protease 7 (OsUBP7), which encodes a protein with deubiquitination activity in vitro, as the primary target of miR1866. Consistent with miRNA-directed repression, OsUBP7 transcript abundance generally showed a spatiotemporal pattern opposite to miR1866 accumulation during rice development. Overexpression of native OsUBP7 (UBP7-OE) or a miR1866-resistant form (mUBP7-OE) phenocopied KO1866 by producing heavier grains with stronger dormancy. The miR1866–OsUBP7 module also altered the expression of genes associated with sucrose and starch metabolism, cell-cycle control, grain development, and abscisic acid (ABA) biosynthesis and signaling. Accordingly, KO1866, UBP7-OE, and mUBP7-OE plants contained more ABA and responded more sensitively to exogenous ABA than wild type. OsUBP7 interacted with OsDA1 (encoded by Os06g0182500) and UBIQUITIN-CONJUGATING ENZYME (OsUCE1; encoded by Os02g0833300), thereby affecting hull cell division and ABA signaling and ultimately regulating grain weight and seed dormancy, respectively. Our results indicate that the miR1866–OsUBP7 module regulates grain weight and seed dormancy in rice, highlighting its potential for engineering crops with improved yields and stronger seed dormancy.

Key words: abscisic acid, grain weight, miR1866,  OsUBP7, seed dormancy

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