Shimin You; Zhigang Zhao; XiaowenYu; Shanshan Zhu; JianWang; Dekun Lei; Jiawu Zhou; Jing Li; Haiyuan Chen; Yanjia Xiao; Weiwei Chen; Qiming Wang; Jiayu Lu; Keyi Chen; Chunlei Zhou; Xin Zhang; Zhijun Cheng; Xiuping Guo; Yulong Ren; Xiaoming Zheng; Shijia Liu; Xi Liu; Yunlu Tian; Ling Jiang; Dayun Tao; ChuanyinWu; & Jianmin Wan

Nature Communications; 2023; IF 16.6

DOI:10.1038/s41467-023-43015-6

ABSTRACT:

Breakdown of reproductive isolation facilitates flow of useful trait genes into crop plants from their wild relatives. Hybrid sterility, a major form of reproductive isolation exists between cultivated rice (Oryza sativa) andwild rice (O. meridionalis, Mer). Here, we report the cloning of qHMS1, a quantitative trait locus controlling hybridmale sterility between these two species. Like qHMS7, another locus we cloned previously, qHMS1 encodes a toxin-antidote system, but differs in the encoded proteins, their evolutionary origin, and action time point during pollen development. In plants heterozygous at qHMS1, ~ 50% of pollens carrying qHMS1-D (an allele from cultivated rice) are selectively killed. In plants heterozygous at both qHMS1 and qHMS7, ~ 75% pollens without copresence of qHMS1-Mer and qHMS7-D are selectively killed, indicating that the antidotes function in a toxin-dependent manner. Our results indicate that different toxin-antidote systems provide stacked reproductive isolation for maintaining species identity and shed light on breakdown of hybrid male sterility.