EGFV, Univ. Bordeaux, Bordeaux Sciences Agro, INRAE, ISVV, Villenave d'Ornon, Bordeaux, France.
IFV, French Institute of Vine and Wine, Domaine de l'Espiguette, Le Grau-du-Roi, France.
Plant Cell Environ. 2024 Jul;47(7):2351-2361. doi: 10.1111/pce.14883. Epub 2024 Mar 22.
Plants are able to naturally graft or inosculate their trunks, branches and roots together, this mechanism is used by humans to graft together different genotypes for a range of purposes. Grafts are considered successful if functional vascular connections between the two genotypes occur. Various techniques can evaluate xylem connections across the graft interface. However, these methods are generally unable to assess the heterogeneity and three-dimensional (3D) structure of xylem vessel connections. Here we present the use of X-ray micro-computed tomography to characterize the 3D morphology of grafts of grapevine. We show that xylem vessels form between the two plants of natural root and human-made stem grafts. The main novelty of this methodology is that we were able to visualize the 3D network of functional xylem vessels connecting the scion and rootstock in human-made stem grafts thanks to the addition of a contrast agent to the roots and improved image analysis pipelines. In addition, we reveal the presence of extensive diagonal xylem connections between the main axial xylem vessels in 2-year old grapevine stems. In conclusion, we present a method that has the potential to provide new insights into the structure and function of xylem vessels in large tissue samples.
植物能够自然地将树干、树枝和根系嫁接到一起，这种机制被人类用于将不同基因型嫁接到一起，以达到各种目的。如果两种基因型之间发生功能性木质部连接，那么嫁接就被认为是成功的。各种技术可以评估嫁接界面处的木质部连接。然而，这些方法通常无法评估木质部导管连接的异质性和三维（3D）结构。在这里，我们展示了使用 X 射线微计算机断层扫描来描述葡萄的自然根和人为茎嫁接的 3D 形态。我们表明，木质部导管在自然根和人为茎嫁接的两个植物之间形成。该方法的主要新颖之处在于，我们能够通过向根部添加造影剂和改进图像分析管道，可视化连接接穗和砧木的功能性木质部导管的 3D 网络。此外，我们还揭示了在 2 年生葡萄茎中主要轴向木质部导管之间存在广泛的对角木质部连接。总之，我们提出了一种方法，有可能为木质部导管在大组织样本中的结构和功能提供新的见解。
