Saladin Siriel, D'Aronco Sara, Ingram Gwyneth, Giorio Chiara
Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK.
Laboratoire Reproduction et Développement des Plantes, ENS de Lyon, CNRS, INRAE, UCBL F-69342 Lyon France.
RSC Adv. 2023 Mar 14;13(13):8487-8495. doi: 10.1039/d2ra07166e.
The plant cuticle covers the plant's entire aerial surface and acts as the outermost protective layer. Despite being crucial for the survival of plants, surprisingly little is known about its biosynthesis. Conventional analytical techniques are limited to the isolation and depolymerization of the polyester cutin, which forms the cuticular scaffold. Although this approach allows the elucidation of incorporated cutin monomers, it neglects unincorporated metabolites participating in cutin polymerization. The feasibility of a novel approach is tested for analysis of unpolymerized cuticular metabolites to enhance the understanding of cuticle biology. Intact cotyledons of and seedlings are immersed in organic solvents for 60 seconds. Extracts are analyzed using high-resolution direct infusion mass spectrometry. A variety of different diffusion routes of plant metabolites across the cuticle are discussed. The results reveal different feasibilities depending on the research question and cuticle permeabilities in combination with the analyte's polarity. Especially hydrophilic analytes are expected to be co-located in the cell wall beneath the cuticle causing systematic interferences when comparing plants with different cuticle permeabilities. These interferences limit data interpretation to qualitative rather than quantitative comparison. In contrast, quantitative data evaluation is facilitated when analyzing cuticle-specific metabolites or plants with similar cuticle permeabilities.
植物角质层覆盖植物的整个地上部分表面，并作为最外层的保护层。尽管其对植物的生存至关重要，但令人惊讶的是，人们对其生物合成知之甚少。传统分析技术仅限于对构成角质层支架的聚酯角质进行分离和解聚。虽然这种方法能够阐明所含的角质单体，但它忽略了参与角质聚合的未结合代谢物。一种新方法的可行性已针对未聚合的角质层代谢物分析进行了测试，以增进对角质层生物学的理解。拟南芥和油菜幼苗的完整子叶在有机溶剂中浸泡60秒。提取物使用高分辨率直接进样质谱法进行分析。讨论了植物代谢物穿过角质层的多种不同扩散途径。结果表明，根据研究问题以及角质层通透性与分析物极性的组合情况，存在不同的可行性。特别是亲水性分析物预计会共定位在角质层下方的细胞壁中，这在比较具有不同角质层通透性的植物时会导致系统性干扰。这些干扰将数据解释限制为定性而非定量比较。相比之下，在分析角质层特异性代谢物或具有相似角质层通透性的植物时，有助于进行定量数据评估。
