Rhomboid-mediated cleavage of the immune receptor XA21 protects grain set and male fertility in rice

S Satyam Vergish (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) X Xiaoen Huang (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) G Guiyun Zhang (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) B Beatriz de Toledo Franceschi (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) J Jian-Liang Li X Xiao-Xia Wu (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) J Joana Nuraj (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) J Jose C. Huguet-Tapia (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) A Apekshya Parajuli (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) X Xiuhua Chen (Centro de Tecnologia Canavieira Genomics) R Ritu Shekhar (Department of Molecular Genetics and Microbiology, University of Florida) D Dali Liu (Department of Chemistry and Biochemistry) W Wu-Ming Xiao (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) S Shijuan Dou (Department of Bioinformatics and Molecular Biology, College of Life Sciences, Hebei Agricultural University) G Guo-zhen Liu (Department of Bioinformatics and Molecular Biology, College of Life Sciences, Hebei Agricultural University) E Erica M. Goss (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida) L Liya Pi (Department of Pathology and Laboratory Medicine, Tulane University) S Sixue Chen K Karen E. Koch W Wen-Yuan Song (Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida)

Abstract

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 Xanthomonas oryzae pv. oryzae , 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. OsRBL3b mRNA transcripts are preferentially expressed in rice spikelets. Rice plants expressing Xa21 but lacking a functional OsRBL3b 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, osrbl3b 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.

Article Details

Volume / Issue Vol. 122, Issue 22
Published June 03, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (20)

S

Satyam Vergish

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

X

Xiaoen Huang

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

G

Guiyun Zhang

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

B

Beatriz de Toledo Franceschi

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

J

Jian-Liang Li

X

Xiao-Xia Wu

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

J

Joana Nuraj

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

J

Jose C. Huguet-Tapia

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

A

Apekshya Parajuli

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

X

Xiuhua Chen

Centro de Tecnologia Canavieira Genomics

R

Ritu Shekhar

Department of Molecular Genetics and Microbiology, University of Florida

D

Dali Liu

Department of Chemistry and Biochemistry

W

Wu-Ming Xiao

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

S

Shijuan Dou

Department of Bioinformatics and Molecular Biology, College of Life Sciences, Hebei Agricultural University

G

Guo-zhen Liu

Department of Bioinformatics and Molecular Biology, College of Life Sciences, Hebei Agricultural University

E

Erica M. Goss

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida

L

Liya Pi

Department of Pathology and Laboratory Medicine, Tulane University

S

Sixue Chen

K

Karen E. Koch

W

Wen-Yuan Song

Department of Plant Pathology, Institute of Food and Agricultural Sciences, University of Florida