Nanoparticles are linked to polar lipids in xylem sap of temperate angiosperm species
Nanoparticles are linked to polar lipids in xylem sap of temperate angiosperm species
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DOI：
10.1093/treephys/tpac054
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发表时间：
2022-10-01
期刊：
影响因子：
4
通讯作者：
Jansen, Steven
中科院分区：
文献类型：
--
作者：
Guan, Xinyi;Schenk, H. Jochen;Jansen, Steven
在之前的研究中，发现被子植物的木质部汁液含有低浓度的纳米颗粒和极性脂质。这项研究的一个主要目标是测试基于以下假设的预测：纳米颗粒主要由来自血管元件原始细胞内容物的极性脂质组成。这些预测包括极性脂质和纳米颗粒的浓度将是相关的，它们都不会穿过凹坑膜，并且它们不会随季节变化，因为它们源自活的血管元件细胞。我们全年收集了六种温带被子植物的木质部汁液，以考虑季节变化。使用 NanoSight 设备和质谱法测量木质部汁液和污染控制样品中纳米颗粒和脂质的浓度。我们发现，纳米粒子和极性脂质的浓度（i）随着提取的汁液量的增加而被稀释，（ii）三个物种之间显着相关，（iii）受血管解剖结构的影响，（iv）非常低且化学成分与污染控制有很大不同，（v）在季节之间几乎没有变化。此外，对于纳米颗粒的数量和尺寸而言，冻融效应较小。木质部汁液脂质包括所有物种中的极性半乳糖脂和磷脂以及两个物种中的中性三酰甘油。这些发现支持了预测，并且暗示了潜在的假设，即木质部汁液中的纳米颗粒由来自活导管元件细胞的原始细胞内容物的极性脂质组成。需要进一步的研究来检查纳米颗粒的形成和稳定性，涉及活体植物木质部导管中的脂质组成以及气、液和固相之间的多相相互作用。
In previous research, xylem sap of angiosperms has been found to include low concentrations of nanoparticles and polar lipids. A major goal of this study was to test predictions arising from the hypothesis that the nanoparticles consist largely of polar lipids from the original cell content of vessel elements. These predictions included that polar lipid and nanoparticle concentrations would be correlated, that they both do not pass through pit membranes and that they do not vary seasonally because they originate from living vessel element cells. We collected xylem sap of six temperate angiosperm species over the whole year to consider seasonal variation. Concentrations of nanoparticles and lipids in xylem sap and contamination control samples were measured with a NanoSight device and mass spectrometry. We found that the concentration of nanoparticles and polar lipids was (i) diluted when an increasing amount of sap was extracted, (ii) significantly correlated to each other for three species, (iii) affected by vessel anatomy, (iv) very low and largely different in chemical composition from contamination controls and (v) hardly variable among seasons. Moreover, there was a minor freezing-thawing effect with respect to nanoparticle amount and size. Xylem sap lipids included polar galactolipids and phospholipids in all species and neutral triacylglycerols in two species. These findings support the predictions and, by implication, the underlying hypothesis that nanoparticles in xylem sap consist of polar lipids from the original cell content of living vessel element cells. Further research is needed to examine the formation and stability of nanoparticles concerning lipid composition and multiphase interactions among gas, liquid and solid phases in xylem conduits of living plants.