The vesicle trafficking gene, OsRab7, is critical for pollen development and male fertility in cytoplasmic male-sterility rice

Suping Ying; Yunting Tang; Wei Yang; Zhao Hu; Ruifeng Huang; Jie Ding; Xiangyun Yi; Jiawei Niu; Zihan Chen; Ting Wang; Wei Liu; Xiaojue Peng

doi:10.1016/j.gene.2024.148423

The vesicle trafficking gene, OsRab7, is critical for pollen development and male fertility in cytoplasmic male-sterility rice

Gene. 2024 Apr 2:915:148423. doi: 10.1016/j.gene.2024.148423. Online ahead of print.

Authors

Suping Ying¹, Yunting Tang¹, Wei Yang¹, Zhao Hu¹, Ruifeng Huang¹, Jie Ding¹, Xiangyun Yi¹, Jiawei Niu¹, Zihan Chen¹, Ting Wang², Wei Liu³, Xiaojue Peng⁴

Affiliations

¹ Key Laboratory of Molecular Biology and Gene Engineering of Jiangxi Province, College of Life Sciences, Nanchang University, Nanchang 330031, China.
² Department of Chemistry, University of Kentucky, Lexington, United States.
³ Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. Electronic address: liuwei@gdaas.cn.
⁴ Key Laboratory of Molecular Biology and Gene Engineering of Jiangxi Province, College of Life Sciences, Nanchang University, Nanchang 330031, China. Electronic address: xiaojuepeng@ncu.edu.cn.

PMID: 38575100
DOI: 10.1016/j.gene.2024.148423

Abstract

Rice cytoplasmic male sterility (CMS) provides an exceptional model for studying genetic interaction within plant nuclei given its inheritable trait of non-functional male gametophyte. Gaining a comprehensive understanding of the genes and pathways associated with the CMS mechanism is imperative for improving the vigor of hybrid rice agronomically, such as its productivity. Here, we observed a significant decrease in the expression of a gene named OsRab7 in the anther of the CMS line (SJA) compared to the maintainer line (SJB). OsRab7 is responsible for vesicle trafficking and loss function of OsRab7 significantly reduced pollen fertility and setting rate relative to the wild type. Meanwhile, over-expression of OsRab7 enhanced pollen fertility in the SJA line while a decrease in its expression in the SJB line led to the reduced pollen fertility. Premature tapetum and abnormal development of microspores were observed in the rab7 mutant. The expression of critical genes involved in tapetum development (OsMYB103, OsPTC1, OsEAT1 and OsAP25) and pollen development (OsMSP1, OsDTM1 and OsC4) decreased significantly in the anther of rab7 mutant. Reduced activities of the pDR5::GUS marker in the young panicle and anther of the rab7 mutant were also observed. Furthermore, the mRNA levels of genes involved in auxin biosynthesis (YUCCAs), auxin transport (PINs), auxin response factors (ARFs), and members of the IAA family (IAAs) were all downregulated in the rab7 mutant, indicating its impact on auxin signaling and distribution. In summary, these findings underscore the importance of OsRab7 in rice pollen development and its potential link to cytoplasmic male sterility.

Keywords: Anther development; Cytoplasm male sterility; OsRab7; Rice.