• Wood, or secondary xylem, is the product of xylogenesis, a developmental process that begins with the proliferation of cambial derivatives and ends with mature xylem fibers and vessels with lignified secondary cell walls. Fully mature xylem has undergone a series of cellular processes, including cell division, cell expansion, secondary wall formation, lignification and programmed cell death. A complex network of interactions between transcriptional regulators and signal transduction pathways controls wood formation. However, the role of metabolites during this developmental process has not been comprehensively characterized.
• To evaluate the role of metabolites during wood formation, we performed a high spatial resolution metabolomics study of the wood‐forming zone of Populus tremula, including laser dissected aspen ray and fiber cells.
• We show that metabolites show specific patterns within the wood‐forming zone, following the differentiation process from cell division to cell death.
• The data from profiled laser dissected aspen ray and fiber cells suggests that these two cell types host distinctly different metabolic processes. Furthermore, by integrating previously published transcriptomic and proteomic profiles generated from the same trees, we provide an integrative picture of molecular processes, for example, deamination of phenylalanine during lignification is of critical importance for nitrogen metabolism during wood formation.

中文翻译：

---

毛白杨木材形成组织的代谢路线图。

• 木材或次生木质部是木糖生成的产物，这是一个发展过程，始于冈比亚衍生物的繁殖，最后以成熟的木质部纤维和带有木质化次生细胞壁的血管结束。完全成熟的木质部经历了一系列细胞过程，包括细胞分裂，细胞扩增，继发壁形成，木质化和程序性细胞死亡。转录调节因子和信号转导途径之间相互作用的复杂网络控制着木材的形成。但是，代谢物在该发育过程中的作用尚未得到全面表征。
• 为了评估代谢物在木材形成过程中的作用，我们对白杨的木材形成区进行了高空间分辨率代谢组学研究，包括激光切割的白杨射线和纤维细胞。
• 我们表明，从细胞分裂到细胞死亡的分化过程之后，代谢产物在木材形成区内显示出特定的模式。
• 来自轮廓激光切割的白杨射线和纤维细胞的数据表明，这两种细胞类型具有截然不同的代谢过程。此外，通过整合先前发表的从同一棵树生成的转录组和蛋白质组图谱，我们提供了分子过程的完整图片，例如，木质化过程中苯丙氨酸的脱氨基对于木材形成过程中的氮代谢至关重要。