Researchers from Huazhong Agriculture University and the Sanming Institute of Agriculture Sciences have successfully identified the dominant male sterility gene in rice, a breakthrough that promises to revolutionize crop breeding processes. The Sanming Dominant Genic Male Sterile (SDGMS) Rice, initially discovered in 2001 by the Sanming Institute of Agricultural Science, exhibits stable and complete male sterility that remains largely unaffected by environmental factors, making it an invaluable asset in crop breeding. Despite its utility, the gene responsible for SDGMS had remained elusive until now.
In their study, titled “Spontaneous movement of a retrotransposon generated genic dominant male sterility providing a useful tool for rice breeding” and published in the National Science Review, the scientists employed a map-based cloning approach to pinpoint the SDGMS gene and elucidate the mechanism underlying its dominant male sterility trait.
In fertile rice plants, the sdgms gene exhibited minimal expression in young panicles and spikelets. In stark contrast, sterile rice plants displayed a critical alteration—a 1978-base pair retrotransposon had relocated to the promoter region of SDGMS, triggering its specific expression in tapetal cells.
The SDGMS gene encodes a ribosome-inactivating protein that operates at the translational level to inhibit protein translation. This leads to the activation of the defense response in rice anthers and subsequently triggers a hypersensitive response and programmed cell death in tapetal cells, resulting in male sterility. This groundbreaking research illustrates that transposable element (TE) movement continues to shape genome evolution and highlights the potential of SDGMS rice as a powerful tool for facilitating outcrossing, eliminating the need for manual emasculation, and significantly enhancing the efficiency of breeding programs.
The study was led by Dr. Qifa Zhang, Dr. Yidan Ouyang (National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research, Hubei Hongshan Laboratory, Huazhong Agricultural University), and Dr. Xianbo Huang (Sanming Institute of Agricultural Sciences).