Feng Zhuo, Sui Qun, Yang Ji-Yuan, Guo Yun, McLoughlin Stephen
Institute of Palaeontology, Yunnan Key Laboratory of Earth System Science, Yunnan Key Laboratory for Palaeobiology, MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming 650500, China.
Institute of Palaeontology, Yunnan Key Laboratory of Earth System Science, Yunnan Key Laboratory for Palaeobiology, MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming 650500, China.
Curr Biol. 2023 Feb 27;33(4):720-726.e2. doi: 10.1016/j.cub.2022.12.043. Epub 2023 Feb 15.
Plants can move in various complex ways in response to external stimuli. These mechanisms include responses to environmental triggers, such as tropic responses to light or gravity and nastic responses to humidity or contact. Nyctinasty, the movements involving circadian rhythmic folding at night and opening at daytime of plant leaves or leaflets, has attracted the attention of scientists and the public for centuries. In his canonical work entitled The Power of Movement in Plants, Charles Darwin carried out pioneering observations to document the diverse range of movements in plants. His systematic examination of plants showing "sleep [folding] movements of leaves" led him to conclude that the legume family (Fabaceae) includes many more nyctinastic species than all other families combined. Darwin also found that a specialized motor organ, the pulvinus, is responsible for most sleep movements of plant leaves, although differential cell division and the hydrolysis of glycosides and phyllanthurinolactone also facilitate nyctinasty in some plants. However, the origin, evolutionary history, and functional benefits of foliar sleep movements remain ambiguous owing to the lack of fossil evidence for this process. Here, we document the first fossil evidence of foliar nyctinasty based on a symmetrical style of insect feeding damage (Folifenestra symmetrica isp. nov.) in gigantopterid seed-plant leaves from the upper Permian (∼259-252 Ma) of China. The pattern of insect damage indicates that the host leaves were attacked when mature but folded. Our finding reveals that foliar nyctinasty extends back to the late Paleozoic and evolved independently among various plant lineages.
植物能够以各种复杂的方式对外部刺激做出反应。这些机制包括对环境触发因素的反应，如对光或重力的向性反应以及对湿度或接触的感性反应。感夜性，即植物叶片或小叶在夜间进行昼夜节律性折叠并在白天展开的运动，几个世纪以来一直吸引着科学家和公众的关注。在其经典著作《植物的运动能力》中，查尔斯·达尔文进行了开创性的观察，记录了植物中多种多样的运动。他对表现出“叶片睡眠[折叠]运动”的植物进行系统研究后得出结论，豆科（Fabaceae）中的感夜性物种比其他所有科的总和还要多。达尔文还发现，一种特殊的运动器官——叶枕，负责植物叶片的大部分睡眠运动，尽管细胞的差异分裂以及糖苷和叶下珠醇内酯的水解在某些植物中也有助于感夜性。然而，由于缺乏这一过程的化石证据，叶片睡眠运动的起源、进化历史和功能益处仍然不明确。在此，我们基于对来自中国上二叠统（约2.59 - 2.52亿年前）的大羽羊齿类种子植物叶片上一种对称的昆虫取食损伤样式（新种对称叶痕叶蜂Folifenestra symmetrica），记录了叶片感夜性的首个化石证据。昆虫损伤的样式表明，宿主叶片在成熟但折叠时受到了攻击。我们的发现揭示，叶片感夜性可追溯到古生代晚期，并且在不同的植物谱系中独立进化。
