The simulation model of growth and cell divisions for the root apex with an apical cell in application to Azolla pinnata

Abstract

In contrast to seed plants, the roots of most ferns have a single apical cell which is the ultimate source of all cells in the root. The apical cell has a tetrahedral shape and divides asymmetrically. The root cap derives from the distal division face, while merophytes derived from three proximal division faces contribute to the root proper. The merophytes are produced sequentially forming three sectors along a helix around the root axis. During development, they divide and differentiate in a predictable pattern. Such growth causes cell pattern of the root apex to be remarkably regular and self-perpetuating. The nature of this regularity remains unknown. This paper shows the 2D simulation model for growth of the root apex with the apical cell in application to Azolla pinnata. The field of growth rates of the organ, prescribed by the model, is of a tensor type (symplastic growth) and cells divide taking principal growth directions into account. The simulations show how the cell pattern in a longitudinal section of the apex develops in time. The virtual root apex grows realistically and its cell pattern is similar to that observed in anatomical sections. The simulations indicate that the cell pattern regularity results from cell divisions which are oriented with respect to principal growth directions. Such divisions are essential for maintenance of peri-anticlinal arrangement of cell walls and coordinated growth of merophytes during the development. The highly specific division program that takes place in merophytes prior to differentiation seems to be regulated at the cellular level.Electronic supplementary materialThe online version of this article (doi:10.1007/s00425-013-1950-9) contains supplementary material, which is available to authorized users.

Root system architecture, physiological and transcriptional traits of soybean (Glycine max L.) in response to water deficit: A review

“…Usually, the root hairs in the mature area of the root tip have a life span of only 1-2 weeks. After the root hairs die, the elongation zone will generate new root hairs to supplement and change the position of the roots in the soil to absorb nutrients (Piekarska-Stachowiak and Nakielski 2013). The formation of root hairs greatly increases the area where the roots absorb nutrients, but the root hairs are susceptible to the availability of soil moisture and develop poorly in arid soils.…”

Topological traits of a cellular pattern versus growth rate anisotropy in radish roots

“…Cells manifest a tendency to remain in a state of equilibrium during organ growth and the associated divisions of cells (Lewis 1928 ; Rivier et al 1995 ; Gibson and Gibson 2009 ). This enables the steady average size of cells within the growing regions to be maintained, which was also confirmed in modeling and simulation of the plant organ growth (Hejnowicz and Karczewski 1993 ; Szymanowska-Pułka et al 2012 ; Piekarska-Stachowiak and Nakielski 2013 ). Moreover, the arrangement of cells in growing regions seems to be to fill the topological space optimally (Rivier et al 1995 ; Gibson and Gibson 2009 ).…”

“…The growth distribution within an organ may be graphically represented by a map of the indicatrices that are determined at selected points (Hejnowicz and Karczewski 1993 ). Based on anatomical observations and the GT definition (Hejnowicz and Romberger 1984 ), this type of field was determined and applied to simulate the growth of the shoot (Nakielski 2000 ) and root apices (Hejnowicz and Karczewski 1993 ; Nakielski and Lipowczan 2012 ; Szymanowska-Pułka et al 2012 ; Piekarska-Stachowiak and Nakielski 2013 ) in various plant species. In the simulations, the plant organ being considered is described in 2D and its cells are represented by polygons.…”

“…Yet, the above-presented short literature review shows that there is a lack of research concerning both the topology and the applicability of Lewis’s Law to the case of the cells in the different tissues/zones of the same organ. From previous studies (Hejnowicz and Karczewski 1993 ; Piekarska-Stachowiak and Nakielski 2013 ), we know that the different tissues and zones of a plant organ grow at different rates. That is why we were interested in performing a detailed analysis of the anisotropy of plant organ growth as well as of the topology of the cells that form the specific zones and tissues of the radish root apex in its axial section.…”

A method to generate the surface cell layer of the 3D virtual shoot apex from apical initials

“…In this way the division plate halved the cell without an additional assumption which is primarily used to specify the position of the division plate in Errera’s rule [ 35 , 36 , 38 ]. A similar way of modifying the division plane that was defined for other division rules was recently tested using the 2D approach [ 49 , 56 , 57 ]. The examples of much stronger changes in the position and orientation of the division plane that were influenced by a random factor were described by Sahlin and Jonson [ 38 ] and Alim et al [ 34 ].…”