A mini foxtail millet with an Arabidopsis-like life cycle as a C4 model system

Yang, Zhirong; Zhang, Haoshan; Li, Xukai; Shen, Huimin; Gao, Jianhua; Hou, Siyu; Zhang, Bin; Mayes, Sean; Bennett, Malcolm; Ma, Jianxin; Wu, Chuanyin; Sui, Yi; Han, Yuanhuai; Wang, Xingchun

Abstract

Over the past few decades, several plant species, including Arabidopsis thaliana, Brachypodium distachyon and rice (Oryza sativa), have been adopted as model plants for various aspects of research. These species, especially Arabidopsis, have had vital roles in making fundamental discoveries and technological advances 1. However, all these model plants use C 3 photosynthe-sis, and discoveries made in these species are not always transferable to, or representative of, C 4 plants such as maize (Zea mays), sor-ghum (Sorghum bicolor) and millets, which are efficient fixers of atmospheric CO 2 into biomass. Thus, it is critical to develop a new model system for studies in these and many other C 4 plants 2. Foxtail millet (S. italica) is a cereal crop that was domesticated from its wild ancestor, green foxtail (Setaria viridis). These two species are evolutionarily close to several bioenergy crops, including switchgrass (Panicum virgatum), napiergrass (Pennisetum purpu-reum) and pearl millet (Pennisetum glaucum), and major cereals such as sorghum, maize and rice 3. In addition, extensive genetic diversity exists in Setaria, with approximately 30,000 accessions preserved in China, India, Japan and the United States 3 as valuable resources for gene-function dissection and elite-allele mining 4. In recent years, the whole-genome sequences of foxtail millet and green foxtail have been made available 5-9 , and both species have been proposed as C 4 model plant systems 3,6. Between these two species, foxtail millet is more suitable as a model plant due to the seed shattering and dor-mancy in green foxtail. Nevertheless, the relatively long life cycle (usually 4-5 months per generation) and large plant size (1-2 m in height) limit the use of foxtail millet as a model plant 3,10-12. To overcome such limitations, we have recently developed a large fox-tail millet ethyl methane sulfonate (EMS)-mutagenized population using Jingu21, a high-yield, high-grain-quality elite variety widely grown in north China in the past few decades. From the mutant population, we identified a miniature mutant (dubbed xiaomi) with a life cycle similar to that of Arabidopsis. Subsequently, we developed genomics and transcriptomics resources and a protocol for efficient transformation of xiaomi, as essential parts of the toolbox for the research community.

Citation

Yang, Z., Zhang, H., Li, X., Shen, H., Gao, J., Hou, S., …Wang, X. (2020). A mini foxtail millet with an Arabidopsis-like life cycle as a C4 model system. Nature Plants, 6, 1167–1178. https://doi.org/10.1038/s41477-020-0747-7

• Journal Article Type: Article
• Acceptance Date: Jul 20, 2020
• Online Publication Date: Aug 31, 2020
• Publication Date: 2020-09
• Deposit Date: Sep 1, 2020
• Publicly Available Date: Mar 1, 2021
• Journal: Nature Plants
• Print ISSN: 2055-026X
• Electronic ISSN: 2055-0278
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Pages: 1167–1178
• DOI: https://doi.org/10.1038/s41477-020-0747-7
• Public URL: https://nottingham-repository.worktribe.com/output/4871760
• Publisher URL: https://www.nature.com/articles/s41477-020-0747-7
• Additional Information: Received: 12 October 2019; Accepted: 20 July 2020; First Online: 31 August 2020; : The authors declare no competing interests.