The RING-Finger Ubiquitin Ligase HAF1 Mediates Heading date 1 Degradation during Photoperiodic Flowering in Rice
The RING-Finger Ubiquitin Ligase HAF1 Mediates Heading date 1 Degradation during Photoperiodic Flowering in Rice
复制标题
环指泛素连接酶HAF1介导水稻光周期开花期间抽穗期1的降解
DOI：
10.1105/tpc.15.00320
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发表时间：
2015-09-01
期刊：
影响因子：
11.6
通讯作者：
Wu, Changyin
中科院分区：
文献类型：
--
作者：
Yang, Ying;Fu, Debao;Wu, Changyin
光周期反应是决定水稻抽穗期的重要因素之一。虽然开花时间基因的节律性表达模式已被报道微调光周期反应，关键开花调节因子的翻译后调控很少被阐明在水稻。抽穗期1（Hd1）编码一个锌指转录因子，该因子在水稻光周期反应中起着重要作用，而光周期反应决定了水稻的区域适应性。然而，鲜为人知的是，在光周期响应过程中的Hd1积累的分子机制。在这里，我们确定了一个C3HC4环结构域的E3泛素连接酶，标题日期相关因子1（HAF 1），它与Hd 1的物理相互作用。HAF 1介导泛素化，并通过26S蛋白酶体依赖性途径靶向Hd 1降解。在短日照和长日照条件下，突变体F11的抽穗开花期均较晚。此外，HAF 1 hd1双突变体在短日照条件下抽穗期与hd1一样晚，而在长日照条件下抽穗期与HAF 1相似，说明HAF 1在短日照条件下可能主要通过Hd1决定抽穗期。此外，高水平的Hd1积累在Hd1中。我们的研究结果表明，HAF 1是必不可少的精确调制的时间在水稻光周期反应的Hd 1积累。
The photoperiodic response is one of the most important factors determining heading date in rice (Oryza sativa). Although rhythmic expression patterns of flowering time genes have been reported to fine-tune the photoperiodic response, posttranslational regulation of key flowering regulators has seldom been elucidated in rice. Heading date 1 (Hd1) encodes a zinc finger transcription factor that plays a crucial role in the photoperiodic response, which determines rice regional adaptability. However, little is known about the molecular mechanisms of Hd1 accumulation during the photoperiod response. Here, we identify a C3HC4 RING domain-containing E3 ubiquitin ligase, Heading date Associated Factor 1 (HAF1), which physically interacts with Hd1. HAF1 mediates ubiquitination and targets Hd1 for degradation via the 26S proteasome-dependent pathway. The haf1 mutant exhibits a later flowering heading date under both short-day and long-day conditions. In addition, the haf1 hd1 double mutant headed as late as hd1 plants under short-day conditions but exhibited a heading date similar to haf1 under long-day conditions, thus indicating that HAF1 may determine heading date mainly through Hd1 under short-day conditions. Moreover, high levels of Hd1 accumulate in haf1. Our results suggest that HAF1 is essential to precise modulation of the timing of Hd1 accumulation during the photoperiod response in rice.