PDF(Pubmed)
Abstract：
Secondary development is a key biological characteristic of woody plants and the basis of wood formation. Exogenous nitrogen can affect the secondary growth of poplar, and some regulatory mechanisms have been found in the secondary xylem. However, the effect of nitrogen on cambium has not been reported. Herein, we investigated the effects of different nitrogen concentrations on cambium development using combined transcriptome and metabolome analysis. The results show that, compared with 1 mM NH4NO3 (M), the layers of hybrid poplar cambium cells decreased under the 0.15 mM NH4NO3 (L) and 0.3 mM NH4NO3 (LM) treatments. However, there was no difference in the layers of hybrid poplar cambium cells under the 3 mM NH4NO3 (HM) and 5 mM NH4NO3 (H) treatments. Totals of 2365, 824, 649 and 398 DEGs were identified in the M versus (vs.) L, M vs. LM, M vs. HM and M vs. H groups, respectively. Expression profile analysis of the DEGs showed that exogenous nitrogen affected the gene expression involved in plant hormone signal transduction, phenylpropanoid biosynthesis, the starch and sucrose metabolism pathway and the ubiquitin-mediated proteolysis pathway. In M vs. L, M vs. LM, M vs. HM and M vs. H, differential metabolites were enriched in flavonoids, lignans, coumarins and saccharides. The combined analysis of the transcriptome and metabolome showed that some genes and metabolites in plant hormone signal transduction, phenylpropanoid biosynthesis and starch and sucrose metabolism pathways may be involved in nitrogen regulation in cambium development, whose functions need to be verified. In this study, from the point of view that nitrogen influences cambium development to regulate wood formation, the network analysis of the transcriptome and metabolomics of cambium under different nitrogen supply levels was studied for the first time, revealing the potential regulatory and metabolic mechanisms involved in this process and providing new insights into the effects of nitrogen on wood development.
摘要：
次生发育是木本植物的关键生物学特性，也是木材形成的基础。外源氮能影响杨树的次生生长,并在次生木质部中发现了一些调节机制。然而,氮对形成层的影响尚未见报道。在这里，我们使用联合转录组和代谢组分析研究了不同氮浓度对形成层发育的影响。结果表明,与1mMNH4NO3(M)相比，在0.15mMNH4NO3（L）和0.3mMNH4NO3（LM）处理下，混合杨树形成层减少。然而,在3mMNH4NO3（HM）和5mMNH4NO3（H）处理下，混合杨树形成层细胞层没有差异。在Mvs.(vs.)L,Mvs.LM,Mvs.HM和Mvs.H组,分别。DEGs的表达谱分析表明外源氮影响了植物激素信号转导基因的表达,苯丙素生物合成，淀粉和蔗糖代谢途径和泛素介导的蛋白水解途径。在Mvs.L,Mvs.LM,Mvs.HM和Mvs.H,差异代谢物富含类黄酮，木脂素,香豆素类和糖类。转录组和代谢组的联合分析表明,植物激素信号转导中的一些基因和代谢产物,苯丙素生物合成和淀粉和蔗糖代谢途径可能参与形成层发育过程中的氮调节，其功能需要验证。在这项研究中,从氮影响形成层发育以调节木材形成的角度来看，首次研究了不同氮供应水平下形成层的转录组和代谢组学网络分析，揭示了参与这一过程的潜在调节和代谢机制，并为氮对木材发育的影响提供了新的见解。
