RETINOBLASTOMA RELATED 1 switches mitosis to meiosis in rice

Yongjie Miao; Hanli You; Huixin Liu; Yangzi Zhao; Jiangzhe Zhao; Yafei Li; Yi Shen; Ding Tang; Baohui Liu; Kewei Zhang; Zhukuan Cheng

doi:10.1016/j.xplc.2024.100857

RETINOBLASTOMA RELATED 1 switches mitosis to meiosis in rice

Plant Commun. 2024 Mar 2:100857. doi: 10.1016/j.xplc.2024.100857. Online ahead of print.

Authors

Yongjie Miao¹, Hanli You², Huixin Liu³, Yangzi Zhao³, Jiangzhe Zhao⁴, Yafei Li³, Yi Shen³, Ding Tang³, Baohui Liu⁵, Kewei Zhang⁶, Zhukuan Cheng⁷

Affiliations

¹ Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou 510006, China; Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Agricultural College of Yangzhou University, Yangzhou 225009, China.
² Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Agricultural College of Yangzhou University, Yangzhou 225009, China.
³ State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China.
⁴ Zhejiang Provincial Key Laboratory of Biotechnology on Specialty Economic Plants, Department of Biology, College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
⁵ Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou 510006, China. Electronic address: liubh@gzhu.edu.cn.
⁶ Zhejiang Provincial Key Laboratory of Biotechnology on Specialty Economic Plants, Department of Biology, College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China. Electronic address: kwzhang@zjnu.edu.cn.
⁷ Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops/Jiangsu Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou 225009, China. Electronic address: zkcheng@genetics.ac.cn.

PMID: 38433446
DOI: 10.1016/j.xplc.2024.100857

Abstract

The transition from mitosis to meiosis is a critical event in the reproductive development of all sexually reproducing species. However, the mechanisms that regulate this process in plants remain largely unknown. Here, we find that the rice (Oryza sativa L.) protein RETINOBLASTOMA RELATED 1 (RBR1) is essential to the transition from mitosis to meiosis. Loss of RBR1 function results in hyper-proliferative sporogenous-cell-like cells (SCLs) in the anther locules during early stages of reproductive development. These hyper-proliferative SCLs are unable to initiate meiosis, eventually stagnating and degrading at late developmental stages to form pollen-free anthers. These results suggest that RBR1 acts as a gatekeeper of entry into meiosis. Furthermore, cytokinin content is significantly increased in rbr1 mutants, whereas the expression of type-B response factors, particularly LEPTO1, is significantly reduced. Given the known close association of cytokinins with cell proliferation, these findings imply that hyper-proliferative germ cells in the anther locules may be attributed to elevated cytokinin concentrations and disruptions in the cytokinin pathway. Using a genetic strategy, the association between germ cell hyper-proliferation and disturbed cytokinin signaling in rbr1 has been confirmed. In summary, we reveal a unique role of RBR1 in the initiation of meiosis; our results clearly demonstrate that the RBR1 regulatory module is connected to the cytokinin signaling pathway and switches mitosis to meiosis in rice.

Keywords: RETINOBLASTOMA RELATED1; cytokinin; meiosis initiation; rice.