Chen Qiang, Zhong Hao, Fan Xian-Wei, Li You-Zhi
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China.
Plant Cell Environ. 2015 Aug;38(8):1479-89. doi: 10.1111/pce.12361. Epub 2014 Jun 9.
Response of maize to photoperiods affects adaption of this crop to environments. We characterize the phenotypes of four temperate-adapted maize foundation parents, Huangzao 4, Chang 7-2, Ye 478 and Zheng 58, and two tropically adapted maize foundation parents, M9 and Shuang M9 throughout the growth stage under three constant photoperiod regimes in a daily cycle of 24 h at 28 °C, and analysed expression of 48 photoperiod response-associated genes. Consequently, long photoperiod (LP) repressed development of the tassels of photoperiod-sensitive maize lines at V9 stage, and caused subsequent failure in flowering; failure of photoperiod-sensitive maize lines in flowering under LP was associated with lower expression of flowering-related genes; photoperiod changes could make a marked impact on spatial layout of maize inflorescence. The larger oscillation amplitude of expression of photoperiod-responsive genes occurred in LP-sensitive maize lines. In conclusion, failure in development of tassels at V9 stage under LP is an early indicator for judging photoperiod sensitivity. The adaptation of temperate-adapted maize lines to LP is due to the better coordination of expression among photoperiod-sensing genes instead of the loss of the genes. High photoperiod sensitivity of maize is due to high expression of circadian rhythm-responding genes improperly early in the light.
玉米对光周期的响应影响其对环境的适应性。我们对四个温带适应型玉米基础亲本黄早4、昌7-2、掖478和郑58，以及两个热带适应型玉米基础亲本M9和双M9在28°C下24小时昼夜周期的三种恒定光周期处理下的整个生长阶段的表型进行了表征，并分析了48个光周期响应相关基因的表达。结果表明，长光周期（LP）在V9期抑制了光周期敏感型玉米品系雄穗的发育，并导致随后的开花失败；光周期敏感型玉米品系在长光周期下开花失败与开花相关基因的低表达有关；光周期变化对玉米花序的空间布局有显著影响。光周期响应基因表达的较大振荡幅度出现在长光周期敏感型玉米品系中。总之，长光周期下V9期雄穗发育失败是判断光周期敏感性的早期指标。温带适应型玉米品系对长光周期的适应是由于光周期感知基因之间表达的更好协调，而不是基因的缺失。玉米的高光周期敏感性是由于昼夜节律响应基因在光照早期不适当的高表达。
