Scholarlink

<p>Seagrasses are marine angiosperms re-adapted to underwater life, forming productive ecosystems and long-term carbon sinks. <i>Posidonia oceanica</i> thrives up to 50 m depth, where light is scarce and spectrally shifted; yet, the molecular basis of its photosynthetic adaptation remains unclear. Here, we report that <i>P. oceanica</i> genetically adapts for highly efficient photon use under dim light by enhancing photosystem antenna size and reducing exciton trapping time. We determine the structures of <i>P. oceanica</i> PSI supercomplexes by cryo-electron microscopy, revealing an expanded antenna system composed of PSI-LHCI, a trimeric phospho-LHCII, and an additional LHCI heterodimer. Low-energy chlorophyll forms associated with LHCI are lost. Ultrafast spectroscopy shows that this loss correlates with faster exciton trapping, which compensates for antenna expansion and enhances light-use efficiency under dim light. We identify key residues responsible for the loss of low-energy forms. Reversion to land-plant ortholog sequences restores red-shifted emission, providing strategies to enhance light-use efficiency in crops.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Structural and spectral adaptation of the seagrass Posidonia oceanica photosystem I to seabed light

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月16日

查看全文
  • Antonello Amelii,
  • Stefano Capaldi,
  • Mattia Russo,
  • Zeno Guardini,
  • Gennaro Sanità,
  • Emanuela Esposito,
  • Irene Olivé,
  • Margherita Maiuri,
  • Luca Dall’Osto,
  • Giulio Cerullo,
  • Gabriele Procaccini,
  • Roberto Bassi

摘要

Seagrasses are marine angiosperms re-adapted to underwater life, forming productive ecosystems and long-term carbon sinks. Posidonia oceanica thrives up to 50 m depth, where light is scarce and spectrally shifted; yet, the molecular basis of its photosynthetic adaptation remains unclear. Here, we report that P. oceanica genetically adapts for highly efficient photon use under dim light by enhancing photosystem antenna size and reducing exciton trapping time. We determine the structures of P. oceanica PSI supercomplexes by cryo-electron microscopy, revealing an expanded antenna system composed of PSI-LHCI, a trimeric phospho-LHCII, and an additional LHCI heterodimer. Low-energy chlorophyll forms associated with LHCI are lost. Ultrafast spectroscopy shows that this loss correlates with faster exciton trapping, which compensates for antenna expansion and enhances light-use efficiency under dim light. We identify key residues responsible for the loss of low-energy forms. Reversion to land-plant ortholog sequences restores red-shifted emission, providing strategies to enhance light-use efficiency in crops.