Arabidopsis FAR-RED ELONGATED HYPOCOTYL3 Integrates Age and Light Signals to Negatively Regulate Leaf Senescence
Arabidopsis FAR-RED ELONGATED HYPOCOTYL3 Integrates Age and Light Signals to Negatively Regulate Leaf Senescence
复制标题
拟南芥远红细长下胚轴3整合年龄和光信号来负调控叶子衰老
DOI：
10.1105/tpc.20.00021
复制
发表时间：
2020-05-01
期刊：
影响因子：
11.6
通讯作者：
Li, Gang
中科院分区：
文献类型：
--
作者：
Tian, Tian;Ma, Lin;Li, Gang
植物通过FAR-RED ELONGATED HYPOCOTYL3和转录因子WRKY28组成的转录模块整合年龄和光信号，协调调节叶片衰老。叶片的衰老受到许多内部信号和外部环境信号的严格调控。低红远红比（R:FR）光、FR光或长时间黑暗促进叶片衰老，高R:FR光或R光抑制叶片衰老。然而，植物评估外部光信号及其内部信号启动和控制叶片衰老过程的精确调节机制在很大程度上仍然未知。在本研究中，我们发现光信号蛋白FAR-RED ELONGATED HYPOCOTYL3 （FHY3）负调控拟南芥（Arabidopsis thaliana）年龄诱导和光介导的叶片衰老。FHY3直接结合转录因子基因WRKY28的启动子区抑制其表达，从而负向调节水杨酸的生物合成和衰老。fhy3功能缺失突变体和wrky28过表达拟南芥植株在高R:FR光照条件下均表现出早期衰老，表明fhy3 - wrky28转录模块在高R:FR光照条件下特异性阻止叶片衰老。本研究揭示了FHY3和WRKY28在叶片衰老中的生理和分子功能，揭示了植物整合动态环境光信号和内部信号启动和控制叶片衰老的调控机制。
Plants integrate age and light signals via a transcriptional module formed by FAR-RED ELONGATED HYPOCOTYL3 and transcription factor gene WRKY28 to coordinately regulate leaf senescence. Leaf senescence is tightly regulated by numerous internal cues and external environmental signals. The process of leaf senescence is promoted by a low ratio of red to far-red (R:FR) light, FR light, or extended darkness and is repressed by a high ratio of R:FR light or R light. However, the precise regulatory mechanisms by which plants assess external light signals and their internal cues to initiate and control the process of leaf senescence remain largely unknown. In this study, we discovered that the light-signaling protein FAR-RED ELONGATED HYPOCOTYL3 (FHY3) negatively regulates age-induced and light-mediated leaf senescence in Arabidopsis (Arabidopsis thaliana). FHY3 directly binds to the promoter region of transcription factor gene WRKY28 to repress its expression, thus negatively regulating salicylic acid biosynthesis and senescence. Both the fhy3 loss-of-function mutant and WRKY28-overexpressing Arabidopsis plants exhibited early senescence under high R:FR light conditions, indicating that the FHY3–WRKY28 transcriptional module specifically prevents leaf senescence under high R:FR light conditions. This study reveals the physiological and molecular functions of FHY3 and WRKY28 in leaf senescence and provides insight into the regulatory mechanism by which plants integrate dynamic environmental light signals and internal cues to initiate and control leaf senescence.