Common to multiple plant species, the contours of the root tips were found to match the "catenary curve" found in buildings such as bridges.
While the sizes and shapes of organs of animals and plants vary from species to species, the contours of organs such as bones and roots appear to be common across species.This time, a group of researchers from Osaka University, Nara Institute of Science and Technology, and Kobe University devised a method to quantitatively analyze the contour of the tip of the root, and the result of mathematically verifying this apparent commonality. Surprisingly, we found that the contours of the roots of 10 species across various plant classification groups such as green onions, cucumbers, violets, nadesico, and cosmos all match the catenary curve.
The catenary curve is used in many buildings around the world, such as suspension bridges, arch bridges, and the Sagrada Familia in Spain, and is a curve that produces a mechanically stable structure.This discovery also shows that the tip of the root of a plant has a mechanically stable shape, forming a similar catenary curve regardless of the difference in seeds and roots.
Furthermore, as a result of observing the process of lateral roots of white-spotted roots that form a catenary curve and conducting computer simulations that introduce the properties of cell division, (1) the cells in the center of the roots divide uniformly and in one direction. It was found that the two properties of elongation and (2) the cells at both ends of the root do not divide are the conditions that form the catenary curve.In both simulation predictions and Arabidopsis thaliana with gene mutations, it was confirmed that the contour of the root tip deviates from the catenary curve when either of these two properties is disturbed.
This study reveals the cross-species commonality of organ shapes and the biological principles that lead to them.In the future, further elucidation of the commonality hidden in the shapes of animal and plant organs is expected, and it may lead to application to technology for effectively growing roots in soil.
Paper information:[Development] Tissue growth constrains root organ outlines into an isometrically scalable shape
