Mechanics, geometry and genetics of epidermal cell shape regulation: different pieces of the same puzzle

Abstract

Pavement cells in the leaf epidermis of many plant species have intricate shapes that fit together much like the pieces of a jigsaw puzzle. They provide an accessible system to understand the development of complex cell shape. Since a protrusion in one cell must fit into the indentation in its neighbor, puzzle cells are also a good system to study how cell shape is coordinated across a plant tissue. Although molecular mechanisms have been proposed for both the patterning and coordination of puzzle cells, evidence is accumulating that mechanical and/or geometric cues may play a more significant role than previously thought.

Protocol for rapid clearing and staining of fixed Arabidopsis ovules for improved imaging by confocal laser scanning microscopy

“…Digital 3D models with cellular resolution are crucial for the quantitative analysis of morphogenesis [23–25]. Our results suggest that this method is suitable for segmentation and the generation of digital 3D model of ovules at different developmental stages using MorphographX software.…”

“…To gain a full understanding of the molecular and cellular basis of organogenesis it is essential to obtain a reliable three-dimensional (3D) representation of the architecture of an entire organ at different stages of development. Faithful digital 3D models with complete cellular resolution are essential prerequisites for quantitative analyses of the multiscale aspects of morphogenesis [23–25]. For example, they allow assessment of cell parameters, such as number, size, length, and number of neighbors.…”

Cellular perspectives for improving mesophyll conductance

“…At the subcellular scale, there has been a focus on lobes as an effective means to increase exposed mesophyll cell area for CO 2 uptake, with a high degree of lobing being linked to high g m (Sage and Sage, ). The formation of lobes in plant cells has been most intensively studied in the leaf epidermis where intricate jig‐saw puzzle forms are common and which, due to their position on the leaf surface, are relatively easy to visualize (Carter et al , ; Sapala et al , ). A series of elegant papers has revealed changes in the cytoskeleton (tubulin/actin) at the neck of lobes, with differential distribution of cell wall epitopes along cell perimeter being produced, which set up local gradients of stress/strain along the cell wall perimeter, resulting in local outgrowth (lobes) (Sampathkumar et al , ).…”

Four-dimensional imaging with virtual reality to quantitatively explore jigsaw puzzle-like morphogenesis of <i>Arabidopsis</i> cotyledon pavement cells

“…In addition, dynamic microtubule networks were observed instead of stable microtubule bundles, which were assumed to locally restrict cell outgrowth in the previous hypothetical models (Belteton et al 2018). Although the observations do not repudiate the impact of cortical microtubules in pavement cell morphogenesis, we should rethink the conventional oversimplified model that cortical microtubule bundles are primarily responsible for jigsaw puzzle-like cell morphogenesis (Eng and Sampathkumar 2018;Sapala et al 2019). Actin filaments have also been suggested to play a key role in jigsaw puzzle-like cell morphogenesis.…”