National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
Biotechnology Research Centre, Jilin Academy of Agricultural Sciences, Changchun 130033, China.
J Integr Plant Biol. 2018 Jun;60(6):465-480. doi: 10.1111/jipb.12632. Epub 2018 Mar 14.
Flowering time is a trait vital to the adaptation of flowering plants to different environments. Here, we report that CCT domain genes play an important role in flowering in maize (Zea mays L.). Among the 53 CCT family genes we identified in maize, 28 were located in flowering time quantitative trait locus regions and 15 were significantly associated with flowering time, based on candidate-gene association mapping analysis. Furthermore, a CCT gene named ZmCOL3 was shown to be a repressor of flowering. Overexpressing ZmCOL3 delayed flowering time by approximately 4 d, in either long-day or short-day conditions. The absence of one cytosine in the ZmCOL3 3'UTR and the presence of a 551 bp fragment in the promoter region are likely the causal polymorphisms contributing to the maize adaptation from tropical to temperate regions. We propose a modified model of the maize photoperiod pathway, wherein ZmCOL3 acts as an inhibitor of flowering either by transactivating transcription of ZmCCT, one of the key genes regulating maize flowering, or by interfering with the circadian clock.
开花时间是植物适应不同环境的重要特征。本文报道 CCT 结构域基因在玉米（Zea mays L.）开花中发挥重要作用。在鉴定的 53 个玉米 CCT 家族基因中，根据候选基因关联作图分析，有 28 个位于开花时间数量性状位点区域，有 15 个与开花时间显著相关。此外，一个命名为 ZmCOL3 的 CCT 基因被证明是开花的抑制剂。ZmCOL3 的过表达使玉米在长日或短日条件下的开花时间延迟了约 4 天。ZmCOL3 3'UTR 缺失一个胞嘧啶和启动子区域存在 551 bp 片段，可能是导致玉米从热带向温带地区适应的因果多态性。我们提出了一个改良的玉米光周期途径模型，其中 ZmCOL3 通过反式激活调节玉米开花的关键基因 ZmCCT 的转录，或通过干扰生物钟，作为开花的抑制剂。
