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

Abstract

BackgroundThe development of cell pattern in the surface cell layer of the shoot apex can be investigated in vivo by use of a time-lapse confocal images, showing naked meristem in 3D in successive times. However, how this layer is originated from apical initials and develops as a result of growth and divisions of their descendants, remains unknown. This is an open area for computer modelling. A method to generate the surface cell layer is presented on the example of the 3D paraboloidal shoot apical dome. In the used model the layer originates from three apical initials that meet at the dome summit and develops through growth and cell divisions under the isotropic surface growth, defined by the growth tensor. The cells, which are described by polyhedrons, divide anticlinally with the smallest division plane that passes depending on the used mode through the cell center, or the point found randomly near this center. The formation of the surface cell pattern is described with the attention being paid to activity of the apical initials and fates of their descendants.ResultsThe computer generated surface layer that included about 350 cells required about 1200 divisions of the apical initials and their derivatives. The derivatives were arranged into three more or less equal clonal sectors composed of cellular clones at different age. Each apical initial renewed itself 7–8 times to produce the sector. In the shape and location and the cellular clones the following divisions of the initial were manifested. The application of the random factor resulted in more realistic cell pattern in comparison to the pure mode. The cell divisions were analyzed statistically on the top view. When all of the division walls were considered, their angular distribution was uniform, whereas in the distribution that was limited to apical initials only, some preferences related to their arrangement at the dome summit were observed.ConclusionsThe realistic surface cell pattern was obtained. The present method is a useful tool to generate surface cell layer, study activity of initial cells and their derivatives, and how cell expansion and division are coordinated during growth. We expect its further application to clarify the question of a number and permanence or impermanence of initial cells, and possible relationship between their shape and oriented divisions, both on the ground of the growth tensor approach.Electronic supplementary materialThe online version of this article (10.1186/s13007-017-0262-7) contains supplementary material, which is available to authorized users.

Does Shoot Apical Meristem Function as the Germline in Safeguarding Against Excess of Mutations?

“…Scale bar, 20 μm. (B) Computer simulation of stochastic stem cell behavior (modified, based on the Video S4, Kucypera et al, 2017 ). In Kucypera et al (2017) , stem cells were defined by a stable point corresponding to the geometric center of SAM surface.…”

“…(B) Computer simulation of stochastic stem cell behavior (modified, based on the Video S4, Kucypera et al, 2017 ). In Kucypera et al (2017) , stem cells were defined by a stable point corresponding to the geometric center of SAM surface. Here, stem cells (red) were defined at t1 by a stable positional information marked by a blue circle.…”

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

“…R 1 and R 2 were determined based on the growth tensor field that was dedicated to the radish root apex (Nakielski 2008 ; see also Supplementary Material, Eq. 1 in Kucypera et al 2017 ). Notice that the anisotropy coefficient takes the value from the range of 0 to 1, where 0 refers to the isotropic growth and 1 refers to the extreme anisotropic growth (growth in one direction).…”

“…In simulations of the growth of plant organs (Nakielski 2008 ; Szymanowska-Pułka and Nakielski 2010 ; Szymanowska-Pułka et al 2012 ; Lipowczan et al 2013 ; Lipowczan and Piekarska-Stachowiak 2014 ; Kucypera et al 2017 ) that are based on the growth tensor field (Hejnowicz and Romberger 1984 ), the stability and realistic appearance of the cell pattern depend heavily on the orientation of the division walls along the PDGs. Some recent modeling studies (Patel et al 2009 ; Sahlin and Jonsson 2010 ; Li et al 2012 ; Sahlin et al 2009 ) have clearly shown that the orientation of cell division also affects the cell topology, especially the number of cell sides versus the cell area.…”

Molecular and Hormonal Regulation of Leaf Morphogenesis in Arabidopsis

“…The CZ is mainly responsible for the maintenance of SAM. The CZ contains both tunica and corpus cells in which the stem cells are present, and below the CZ is the organizing center (OC) [ 14 ]. The tunica and corpus cells of the CZ are symplasmically interconnected through the plasmodesmata [ 15 , 16 ].…”