Gao He, Jin Mingna, Zheng Xiao-Ming, Chen Jun, Yuan Dingyang, Xin Yeyun, Wang Maoqing, Huang Dongyi, Zhang Zhe, Zhou Kunneng, Sheng Peike, Ma Jin, Ma Weiwei, Deng Huafeng, Jiang Ling, Liu Shijia, Wang Haiyang, Wu Chuanyin, Yuan Longping, Wan Jianmin
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, 100081 Beijing, China; National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, 210095 Nanjing, China;
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, 100081 Beijing, China;
Proc Natl Acad Sci U S A. 2014 Nov 18;111(46):16337-42. doi: 10.1073/pnas.1418204111. Epub 2014 Nov 5.
Success of modern agriculture relies heavily on breeding of crops with maximal regional adaptability and yield potentials. A major limiting factor for crop cultivation is their flowering time, which is strongly regulated by day length (photoperiod) and temperature. Here we report identification and characterization of Days to heading 7 (DTH7), a major genetic locus underlying photoperiod sensitivity and grain yield in rice. Map-based cloning reveals that DTH7 encodes a pseudo-response regulator protein and its expression is regulated by photoperiod. We show that in long days DTH7 acts downstream of the photoreceptor phytochrome B to repress the expression of Ehd1, an up-regulator of the "florigen" genes (Hd3a and RFT1), leading to delayed flowering. Further, we find that haplotype combinations of DTH7 with Grain number, plant height, and heading date 7 (Ghd7) and DTH8 correlate well with the heading date and grain yield of rice under different photoperiod conditions. Our data provide not only a macroscopic view of the genetic control of photoperiod sensitivity in rice but also a foundation for breeding of rice cultivars better adapted to the target environments using rational design.
现代农业的成功在很大程度上依赖于培育具有最大区域适应性和产量潜力的作物。作物种植的一个主要限制因素是它们的开花时间，这受到日照长度（光周期）和温度的强烈调节。在这里，我们报告了抽穗期7（DTH7）的鉴定和表征，它是水稻光周期敏感性和谷物产量的一个主要基因位点。基于图谱的克隆显示，DTH7编码一种假反应调节蛋白，其表达受光周期调节。我们表明，在长日照条件下，DTH7在光受体phytochrome B的下游起作用，抑制Ehd1的表达，Ehd1是“成花素”基因（Hd3a和RFT1）的上调因子，导致开花延迟。此外，我们发现DTH7与粒数、株高和抽穗期7（Ghd7）以及DTH8的单倍型组合与不同光周期条件下水稻的抽穗期和谷物产量密切相关。我们的数据不仅提供了水稻光周期敏感性遗传控制的宏观视角，也为利用合理设计培育更适应目标环境的水稻品种奠定了基础。
