“Touching the Void”
Mechanical characterisation of the developing cell wall layers of tension wood fibres by Atomic Force Microscopy
Recommendation: posted 08 July 2022, validated 08 July 2022
Gardiner, B. (2022) “Touching the Void”. Peer Community in Forest and Wood Sciences, 100007. https://doi.org/10.24072/pci.forestwoodsci.100007
Understanding the processes allowing trees to orientate their stems and branches requires an understanding of the mechanical properties of individual cells. As the cells are formed, maturation stresses are created that can lead to the reorientation of the tree. But measuring the properties within the different wood cells produced in normal wood, tension wood or compression wood requires measurements at very fine spatial resolution and the wood cells must remain in-situ so that the cell mechanical characteristics are preserved. In the article of Arnould et al (2022), measurements of the mechanical characteristics of poplar tension wood were measured in comparison to normal wood at different distances from the cambium and therefore different levels of maturation. The work required incredible care to embed the wood in resin, to cut the wood with extremely sharp microtone blades in order to minimize artefacts in the measurements, and then ultra-careful atomic force microscope (AFM) measurements across cell walls from the edge of the lumen to the middle lamella at extremely high spatial resolution. The result is a detailed picture of the kinetic development and maturation of tension wood cells in a tree. The measurements showed that the G-layer reaches close to its final stiffness long before its final thickness, and this is different from the maturation kinetics of other cell wall layers where thickening and stiffening are generally synchronous. Finally, although the G-layer in poplar tension wood fibres and in flax phloem fibres are in many ways very similar there are clear differences in the kinetics of their development and maturation. The detailed information presented in this paper can therefore help to clarify the different hypothetical mechanisms proposed to explain excess stress generation in the tension wood of trees and help move us towards a full understanding of how the “muscles” of trees work.
Arnould O, Capron M, Ramonda M, Laurans F, Alméras T, Pilate G, Clair B (2022) Mechanical characterisation of the developing cell wall layers of tension wood fibres by Atomic Force Microscopy. bioRxiv, 2021.09.23.461481, ver. 4 peer-reviewed and recommended by Peer Community in Forest and Wood Science. https://doi.org/10.1101/2021.09.23.461481
The recommender in charge of the evaluation of the article and the reviewers declared that they have no conflict of interest (as defined in the code of conduct of PCI) with the authors or with the content of the article. The authors declared that they comply with the PCI rule of having no financial conflicts of interest in relation to the content of the article.
Evaluation round #2
DOI or URL of the preprint: https://www.biorxiv.org/content/10.1101/2021.09.23.461481v3
Version of the preprint: 2
Author's Reply, 07 Jul 2022
Decision by Barry Gardiner, posted 27 Jun 2022
The paper is very interesting and worthy of publication. But I found some small editorial mistakes and a couple of places where all was not clear. Please look at the uploaded annotated version of your paper and make any necessary changes and upload a revised version of your manuscript.
Barry GardinerDownload recommender's annotations
Evaluation round #1
DOI or URL of the preprint: https://www.biorxiv.org/content/10.1101/2021.09.23.461481v1.full
Version of the preprint: 1
Author's Reply, 09 Jun 2022
Decision by Barry Gardiner, posted 14 Mar 2022
The article has been evaluated by two reviewers with expertise in this area of wood science. They both are positive about the manuscript and recommend publication. But they have also made valuable recommendations for improvement. In particular, the paper needs to give the work "a more general focus" in order to make the findings of wider interest than just those readers specialising in the specific issue of the cell wall layers of tension wood fibres. Such an expanded focus can be provided in the Introduction and Discussion as described by one of the reviewers.
The issue of data avialability is also very important. Normally, with open access papers the data used in the paper is made available in order to be usable for validation and confirmation by other researchers. Is it possible to make the data available with its own DOI such as using, e.g. the Dryad Digital Repository https://datadryad.org/stash or some similar system?
Please attend to the reviewer comments and provide an updated version of your manuscript.