Genomic, Transcriptomic, and Phenomic Variation Reveals the Complex Adaptation of Modern Maize Breeding

• Published in: 分子植物：英文版 2015, Vol.8 (1), p.871-884
• Main Author: Haijun Liu Xiaqing Wang Marilyn L. Warburton Weiwei Wen Minliang Jin Min Deng Jie Liu Hao Tong Qingchun Pan Xiaohong Yang Jianbing Yan
• Format: Article
• Language: English
• Subjects: 农业环境; 基因组; 基因表达数据; 玉米育种; 表型变异; 转录组; 适应性; 适应过程
• ISSN: 1674-2052; 1752-9867

The temperate-tropical division of early maize germplasms to different agricultural environments was arguably the greatest adaptation process associated with the success and near ubiquitous importance of global maize production. Deciphering this history is challenging, but new insight has been gained from examining 558 529 single nucleotide polymorphisms, expression data of 28 769 genes, and 662 traits collected from 368 diverse temperate and tropical maize inbred lines in this study. This is a new attempt to systematically exploit the mechanisms of the adaptation process in maize. Our results indicate that divergence between tropical and temperate lines apparently occurred 3400-6700 years ago. Seven hundred and one genomic selection signals and transcriptomic variants including 2700 differentially expressed individual genes and 389 rewired co-expression network genes were identified. These candidate signals were found to be functionally related to stress responses, and most were associated with directionally selected traits, which may have been an advantage under widely varying environmental conditions faced by maize as it was migrated away from its domestication center. Our study also clearly indicates that such stress adaptation could involve evolution of protein-coding sequences as well as transcriptome-level regulatory changes. The latter process may be a more flexible and dynamic way for maize to adapt to environmental changes along its short evolutionary history.