Dipartimento di Biologia, Ecologia e Scienza della Terra, Università della Calabria (DiBEST-UNICAL), 87036 Arcavacata di Rende, Italy.
Department of Plant Biology and Soil Science, Campus Lagoas-Marcosende, University of Vigo, 36310 Vigo, Spain.
Int J Mol Sci. 2021 Jul 7;22(14):7305. doi: 10.3390/ijms22147305.
Coumarin is a phytotoxic natural compound able to affect plant growth and development. Previous studies have demonstrated that this molecule at low concentrations (100 µM) can reduce primary root growth and stimulate lateral root formation, suggesting an auxin-like activity. In the present study, we evaluated coumarin's effects (used at lateral root-stimulating concentrations) on the root apical meristem and polar auxin transport to identify its potential mode of action through a confocal microscopy approach. To achieve this goal, we used several GFP transgenic lines (for polar auxin transport evaluation), immunolabeling techniques (for imaging cortical microtubules), and GC-MS analysis (for auxin quantification). The results highlighted that coumarin induced cyclin B accumulation, which altered the microtubule cortical array organization and, consequently, the root apical meristem architecture. Such alterations reduced the basipetal transport of auxin to the apical root apical meristem, inducing its accumulation in the maturation zone and stimulating lateral root formation.
香豆素是一种具有植物毒性的天然化合物，能够影响植物的生长和发育。先前的研究表明，这种分子在低浓度（100µM）时可以减少主根的生长并刺激侧根的形成，表明具有类似生长素的活性。在本研究中，我们评估了香豆素（在刺激侧根形成的浓度下使用）对根冠顶端分生组织和极性生长素运输的影响，以通过共聚焦显微镜方法确定其潜在的作用模式。为了实现这一目标，我们使用了几种 GFP 转基因系（用于极性生长素运输评估）、免疫标记技术（用于成像皮层微管）和 GC-MS 分析（用于生长素定量）。结果表明，香豆素诱导了细胞周期蛋白 B 的积累，从而改变了微管皮层阵列的组织，进而改变了根冠顶端分生组织的结构。这种改变减少了生长素向根冠顶端分生组织的向基运输，导致其在成熟区积累，并刺激侧根的形成。
