Rhomboid-mediated cleavage of the immune receptor XA21 protects grain set and male fertility in rice
To maintain growth and to successfully reproduce, organisms must protect key functions in specific tissues, particularly when countering pathogen invasion using internal defensive proteins that may disrupt their own developmental processes. The rice immune receptor XA21 confers race-specific resistance against <i>Xanthomonas oryzae</i> pv. <i>oryzae</i>, which causes the deadly disease bacterial leaf blight. Here, we demonstrate that XA21 is cleaved by the rhomboid-like protease OsRBL3b, likely within its transmembrane domain. <i>OsRBL3b</i> mRNA transcripts are preferentially expressed in rice spikelets. Rice plants expressing <i>Xa21</i> but lacking a functional <i>OsRBL3b</i> displayed impaired anther dehiscence and pollen viability, resulting in male sterility and yield reduction with high levels of XA21 protein present in spikelets during anthesis. In leaves, <i>osrbl3b</i> mutants expressing XA21 had normal levels of this resistance protein and disease immunity. This balance between reproduction and disease resistance through the specific expression of a rhomboid protease may be key to limiting the detrimental effects of an active immune response and may be useful in future for genetic improvement of crops.
Authors
- Apekshya Parajuli (ORCID: https://orcid.org/0009-0003-0295-9274)
- Xiaoen Huang (ORCID: https://orcid.org/0000-0002-7514-1663)
- Liya Pi (ORCID: https://orcid.org/0000-0002-9868-7677)
- Dali Liu (ORCID: https://orcid.org/0000-0002-6831-6592)
- Jian‐Liang Li
- Ritu Shekhar (ORCID: https://orcid.org/0000-0003-3397-6061)
- Karen E. Koch (ORCID: https://orcid.org/0000-0003-1469-8799)
- Satyam Vergish (ORCID: https://orcid.org/0000-0002-2991-3511)
- Erica M. Goss (ORCID: https://orcid.org/0000-0003-3512-2107)
- Xiuhua Chen (ORCID: https://orcid.org/0000-0003-2134-3726)
- José C. Huguet‐Tapia (ORCID: https://orcid.org/0000-0001-7667-1167)
- Sixue Chen (ORCID: https://orcid.org/0000-0002-6690-7612)
- Guozhen Liu (ORCID: https://orcid.org/0000-0002-0556-6404)
- Xiaoxia Wu (ORCID: https://orcid.org/0000-0002-1545-414X)
- Shijuan Dou (ORCID: https://orcid.org/0000-0002-7124-1480)
- Wen Xiao (ORCID: https://orcid.org/0000-0002-7654-9839)
- Guiyun Zhang
- Wen‐Yuan Song (ORCID: https://orcid.org/0000-0002-3179-7097)
- Beatriz de Toledo Franceschi
- Joana Nuraj
Institutions
- Hebei Agricultural University (CN)
- Tulane University (US)
- Sugarcane Research Center (Brazil) (BR)
- University of Florida (US)
- University of Mississippi (US)
- National Institute of Environmental Health Sciences (US)
- Hebei University (CN)
Publication Details
- Journal
- Proceedings of the National Academy of Sciences
- Published
- 2025-05-30
- DOI
- https://doi.org/10.1073/pnas.2502025122
- Citations
- 3
- Primary Topic
- Plant Parasitism and Resistance
- Type
- article
- Field-Weighted Citation Impact
- 5.25
Funders
- National Science Foundation
- U.S. Department of Agriculture
- National Institute of Food and Agriculture
- National Institute of Environmental Health Sciences