GEOMAR Centre for Marine Biotechnology, Research Unit Marine Natural Products Chemistry, GEOMAR Helmholtz Centre for Ocean Research Kiel, Am Kiel Kanal 44, 24106, Kiel, Germany.
Research Unit Marine Benthic Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany.
Sci Rep. 2019 Feb 26;9(1):3323. doi: 10.1038/s41598-019-39212-3.
Plants rely on both mechanical and chemical defence mechanisms to protect their surfaces against microorganisms. The recently completed genome of the eelgrass Zostera marina, a marine angiosperm with fundamental importance for coastal ecosystems, showed that its re-adaptation from land to the sea has led to the loss of essential genes (for chemical communication and defence) and structural features (stomata and thick cuticle) that are typical of terrestrial plants. This study was designed to understand the molecular nature of surface protection and fouling-control strategy of eelgrass against marine epiphytic yeasts. Different surface extraction methods and comparative metabolomics by tandem mass spectrometry (LC-MS/MS) were used for targeted and untargeted identification of the metabolite profiles of the leaf surface and the whole tissue extracts. Desorption electrospray ionization-imaging mass spectrometry (DESI-IMS) coupled with traditional bioassays revealed, for the first time, the unique spatial distribution of the eelgrass surface-associated phenolics and fatty acids, as well as their differential bioactivity against the growth and settlement of epiphytic yeasts. This study provides insights into the complex chemical defence system of the eelgrass leaf surface. It suggests that surface-associated metabolites modulate biotic interactions and provide chemical defence and structural protection to eelgrass in its marine environment.
植物依靠机械和化学防御机制来保护其表面免受微生物的侵害。最近完成的海洋被子植物鳗草（Zostera marina）基因组研究表明，鳗草从陆地重新适应海洋生活导致了一些关键基因（用于化学通讯和防御）和结构特征（气孔和厚角质层）的丧失，而这些特征是典型的陆地植物所具有的。本研究旨在了解鳗草表面保护的分子特性以及其对海洋附生酵母的防污控制策略。采用不同的表面提取方法和串联质谱（LC-MS/MS）比较代谢组学，对叶片表面和整个组织提取物的代谢物图谱进行靶向和非靶向鉴定。解吸电喷雾电离成像质谱（DESI-IMS）与传统生物测定相结合，首次揭示了鳗草表面相关酚类和脂肪酸的独特空间分布，以及它们对附生酵母生长和定殖的差异生物活性。本研究深入了解了鳗草叶片表面复杂的化学防御系统。它表明，表面相关代谢物调节生物相互作用，并为鳗草在海洋环境中提供化学防御和结构保护。
