Du Juan, Xie Hong-Li, Zhang De-Qiang, He Xin-Qiang, Wang Min-Jie, Li Ying-Zhang, Cui Ke-Ming, Lu Meng-Zhu
College of Life Sciences, Peking University, Beijing, P. R. China.
Proteomics. 2006 Feb;6(3):881-95. doi: 10.1002/pmic.200401348.
Wood formation is a complex process composing many biological events. To access its key developmental stages, we have established a regeneration system that can mimic the initiation and differentiation of cambium cells for Chinese white poplar. Anatomical studies showed that new cambium and xylem re-appeared in sequence within a few weeks after being debarked. This provides the opportunity to follow key stages of wood formation by sampling clonal trees at different regeneration times. We used this system in combination with a proteomic approach to analyze proteins expressed in different regeneration stages. PMFs for 244 proteins differentially displayed were obtained and queried against public databases. Putative functions of 199 of these proteins were assigned and classified. Regulatory genes for cell cycle progression, differentiation and cell fate were expressed in the formation of cambial tissue, while 27 genes involved in secondary wall formation were predominantly found in the xylem developing stage. This indicates that the change of gene expression pattern is corresponding to the progression of second vascular system regeneration when and where the key events of wood development occur. Further exploration of these interesting genes may provide insight into the molecular mechanisms of wood formation.
木材形成是一个由许多生物学事件组成的复杂过程。为了了解其关键发育阶段，我们建立了一个再生系统，该系统可以模拟毛白杨形成层细胞的起始和分化。解剖学研究表明，去皮后几周内新的形成层和木质部会依次重新出现。这为通过在不同再生时间对克隆树进行采样来追踪木材形成的关键阶段提供了机会。我们将这个系统与蛋白质组学方法相结合，来分析在不同再生阶段表达的蛋白质。获得了244种差异显示蛋白质的肽质量指纹图谱，并针对公共数据库进行查询。对其中199种蛋白质的推定功能进行了指定和分类。细胞周期进程、分化和细胞命运的调控基因在形成层组织形成过程中表达，而27个参与次生壁形成的基因主要在木质部发育阶段被发现。这表明基因表达模式的变化与第二维管系统再生的进程相对应，而木材发育的关键事件正是在此时此地发生。对这些有趣基因的进一步探索可能会为木材形成的分子机制提供深入了解。
