Zeng Yafei, Wen Jianyu, Zhao Weibo, Wang Qiong, Huang Wenchao
State Key Laboratory of Hybrid Rice, Key Laboratory for Research and Utilization of Heterosis in Indica Rice, The Yangtze River Valley Hybrid Rice Collaboration & Innovation Center, College of Life Sciences, Wuhan University, Wuhan, China.
Front Plant Sci. 2020 Jan 9;10:1663. doi: 10.3389/fpls.2019.01663. eCollection 2019.
Significant increases in rice yield and stress resistance are constant demands for breeders. However, high yield and high stress resistance are often antagonistic to each other. Here, we report several new rice mutants with high yield and excellent cold tolerance that were generated by simultaneously editing three genes, (a panicle length gene), (a grain size gene) and (a cold tolerance gene) with the CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-associated protein 9) system. We edited two target sites of each gene with high efficiency: 53% for -site1, 42% for -site2, 66% for -site1, 63% for -site2, 63% for -site1, and 58% for -site2. Consequently, the mutants, the mutants, and the mutants exhibited increased panicle length, enlarged grain size and increased cold tolerance, respectively. Then nine transgenic lines of the , six lines of and six lines of were also acquired, and their yield related traits and cold tolerance corresponded to the genes being edited. Additionally, we obtained eight triple mutants by editing all three genes simultaneously. Aside from the and mutants, the remaining six mutants had off-target events at the putative off-target site of -site1. The results also showed that the T generations of these two mutants exhibited higher yield and better cold tolerance compared with the wild type. Together, these results demonstrated that new and excellent rice varieties with improved yield and abiotic stress resistance can be generated through gene editing techniques and may be applied to rice breeding. Furthermore, our study proved that the comprehensive agronomic traits of rice can be improved with the CRISPR-Cas9 system.
提高水稻产量和抗逆性是育种者一直以来的需求。然而，高产和高抗逆性往往相互拮抗。在此，我们报告了几个通过利用CRISPR-Cas9（规律成簇间隔短回文重复序列相关蛋白9）系统同时编辑三个基因（一个穗长基因、一个粒型基因和一个耐寒基因）而产生的高产且耐寒性优异的新水稻突变体。我们高效地编辑了每个基因的两个靶点：-位点1的编辑效率为53%，-位点2为42%；-位点1为66%，-位点2为63%；-位点1为63%，-位点2为58%。结果，突变体、突变体和突变体分别表现出穗长增加、粒型增大和耐寒性增强。随后还获得了9个转基因株系、6个转基因株系和6个转基因株系，它们与产量相关的性状和耐寒性与所编辑的基因相对应。此外，我们通过同时编辑所有三个基因获得了8个三突变体。除了和突变体之外，其余6个突变体在-位点1的假定脱靶位点发生了脱靶事件。结果还表明，这两个突变体的T代与野生型相比表现出更高的产量和更好的耐寒性。总之，这些结果表明通过基因编辑技术可以培育出产量和非生物胁迫抗性得到改善的新型优良水稻品种，并可应用于水稻育种。此外，我们的研究证明了利用CRISPR-Cas9系统可以改善水稻的综合农艺性状。
