Original link: https://youtu.be/GrGLTyStEr0
Soil biota have important effects on crop productivity, but can be difficult to study in situ. Laser ablation tomography (LAT) is a novel method that allows for rapid, three-dimensional quantitative and qualitative analysis of root anatomy, providing new opportunities to investigate interactions between roots and edaphic organisms. LAT was used for analysis of maize roots colonised by arbuscular mycorrhizal fungi, maize roots herbivorized by western corn rootworm, barley roots parasitized by cereal cyst nematode, and common bean roots damaged by Fusarium. UV excitation of root tissues affected by edaphic organisms resulted in differential autofluorescence emission, facilitating the classification of tissues and anatomical features. Samples were spatially resolved in three dimensions, enabling quantification of the volume and distribution of fungal colonization, western corn rootworm damage, nematode feeding sites, tissue compromised by Fusarium, and as well as root anatomical phenotypes. Owing to its capability for high-throughput sample imaging, LAT serves as an excellent tool to conduct large, quantitative screens to characterize genetic control of root anatomy and interactions with edaphic organisms. Additionally, this technology improves interpretation of root–organism interactions in relatively large, opaque root segments, providing opportunities for novel research investigating the effects of root anatomical phenes on associations with edaphic organisms.
The video shows the LAT scan of maize (Zea mays) root segment colonised with AMF. AMF colonisation was successfully segmented from maize root tissue due to differences in autofluorescence between root and fungal cell walls. Distinct autofluorescence emission spectra were observed for arbuscules, cortical tissue, and stele tissue. AMF are characterized by their yellow fluorescence with a dominant wavelength of 583.9 nm , which was not present in non-colonised cortical tissues and allowed for the rapid segmentation of fungal structures. Cortical tissue was characterized by a blue fluorescence with a dominant wavelength of 477.2 nm, while stele tissue fluoresced orange with a dominant wavelength of 588.6 nm. The spatial distribution of AMF colonization in the cortex was characterised in relation to root anatomy, and volumes of these structures could be quantified in a semi-automatic manner.
Keywords: Cereal cyst nematode, Fusarium, mycorrhizae, root anatomy, root phenotyping, western corn rootworm, maize,
Citation: Christopher F Strock, Hannah M Schneider, Tania Galindo-Castañeda, Benjamin T Hall, Bart Van Gansbeke, Diane E Mather, Mitchell G Roth, Martin I Chilvers, Xiangrong Guo, Kathleen Brown, Jonathan P Lynch, Laser ablation tomography for visualization of root colonization by edaphic organisms, Journal of Experimental Botany, Volume 70, Issue 19, 1 October 2019, Pages 5327–5342, https://doi.org/10.1093/jxb/erz271
Published on: 13 June 2019
Attribution 4.0 International — CC BY 4.0 - Creative Commons
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