Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Muthgasse, Vienna, Austria.
Tree Physiol. 2018 Oct 1;38(10):1526-1537. doi: 10.1093/treephys/tpy073.
The transition from the living water-transporting sapwood to heartwood involves in many tree species impregnation with extractives. These differ in amount and composition, and enhance resistance against bacteria, insects or fungi. To understand the synthesis, transport and impregnation processes new insights into the biochemical processes are needed by in-situ methods. Here we show the extractive distribution in pine (Pinus sylvestris) microsections with a high lateral resolution sampled in a non-destructive manner using Confocal Raman Microscopy. Integrating marker bands of stilbenes and lipids enables to clearly track the rapid change from sapwood to heartwood within one tree ring. The higher impregnation of the cell corner, compound middle lamella, the S3 layer and pits reveals the optimization of decay resistance on the micron-level. Furthermore, deposits with changing chemical composition are elucidated in the rays and lumen of the tracheids. The spectral signature of these deposits shows the co-location of lipids and pinosylvins with changing ratios from the living to the dead tissue. The results demonstrate that the extractive impregnation on the micro- and nano-level is optimized by a symbiotic relationship of lipids and pinosylvins to enhance the tree's resistance and lifetime.
从富含水分的边材向心材转变的过程涉及许多树种的浸提物的浸渍。这些浸提物在数量和成分上有所不同，提高了树木对细菌、昆虫或真菌的抵抗力。为了了解生物合成、运输和浸渍过程，需要原位方法提供对生化过程的新见解。在这里，我们使用共聚焦拉曼显微镜以高横向分辨率非破坏性地对取自松树（Pinus sylvestris）微切片中的浸提物分布进行了研究。整合芪类和脂类的标记带，可清晰地跟踪同一树轮中从边材到心材的快速变化。细胞角、复合中层、S3 层和纹孔的更高浸渍程度揭示了在微米级水平上对腐烂的优化抵抗。此外，还阐明了在射线和管胞腔中具有变化化学组成的沉积物。这些沉积物的光谱特征表明，脂类和松脂素的共存，其比例从活体组织到死亡组织发生变化。研究结果表明，浸提物在微观和纳米水平上的浸渍是通过脂类和松脂素的共生关系来优化的，以增强树木的抵抗力和寿命。
