micro-CT analysis of grafts of grapevine

Résumé 0

We recommend using Fiji/imageJ software to open the three micro-computed tomography TIFF stacks, which are of a natural root graft and a man-made stem graft before (T0) and 24h after (T24) iohexol labelling. Stacks were acquired on an EasyTom 150 (RX solutions). The natural root and man-made stem grafts were imaged with a spatial resolution of 14.1621 and 29.2186 µm/voxel respectively. The scanned area was approximately 2 and 4 cm in length for the root and man-made stem graft respectively. Scans were done by rotating the sample 360° at < 0.26° rotation steps. Each scan took around 5 min. The X-ray source was set at 60 kV and 301 μA. The distance between the X-ray source and the detector (sdd) was 475 mm for the root and 379 mm for the stem graft. The distance between the source and the object (sod) was 53 mm for root and 87 mm for stem graft. For the stem graft, we first made a control acquisition without iohexol for each plant (called T0). Then, we cut the roots underwater and immersed the roots in an iohexol solution at 60 mg/mL for 24 h. The grafts were then placed in a growth chamber so that the transpiration stream could label functional xylem vessels that cross the graft interface. A second acquisition was done after 24 h (called T24). The 3D reconstructions of the stacks are available in XML format: unireconstruction omega_root for the natural root graft, and unireconstruction omega_graft_t0 and unireconstruction omega_graft_t24 for the stem graft before and after labelling with iohexol. Funding: This work was funded with the project EFA 324/19 - VITES QUALITAS, 65 % co-funded by the European Regional Development Fund (FEDER) through the Interreg Program V-A Spain-France-Andorra (POCTEFA 2014-2020) and VitiGraft funded by the Plant2Pro® Carnot Institute in the frame of its 2021 call, Plant2Pro® is supported by ANR (agreement #21-CARN-024-01 – 2021). The authors want to thank all their colleagues for their assistance. Special thanks to Javier Eraso and Rafael García from Vitis Navarra nursery. Micro-CT acquisitions were performed in Montpellier, France, at the MRI platform member of the national infrastructure France-BioImaging and supported by the French National Research Agency (ANR-10-INBS-04, « Investments for the Future »), and of the Labex CEMEB (ANR-10-LABX-0004) and NUMEV (ANR-10-LABX-0020).