Spatiotemporal variation of leaf epidermal cell growth: a quantitative analysis of Arabidopsis thaliana wild-type and triple cyclinD3 mutant plants.
OBJECTIVE
The epidermis of an expanding dicot leaf is a mosaic of cells differing in identity, size and differentiation stage. Here hypotheses are tested that in such a cell mosaic growth is heterogeneous and changes with time, and that this heterogeneity is not dependent on the cell cycle regulation per se.


METHODS
Shape, size and growth of individual cells were followed with the aid of sequential replicas in expanding leaves of wild-type Arabidopsis thaliana and triple cyclinD3 mutant plants, and combined with ploidy estimation using epi-fluorescence microscopy.


RESULTS
Relative growth rates in area of individual epidermal cells or small cell groups differ several fold from those of adjacent cells, and change in time. This spatial and temporal variation is not related to the size of either the cell or the nucleus. Shape changes and growth within an individual cell are also heterogeneous: anticlinal wall waviness appears at different times in different wall portions; portions of the cell periphery in contact with different neighbours grow with different rates. This variation is not related to cell growth anisotropy. The heterogeneity is typical for both the wild type and cycD3.


CONCLUSIONS
Growth of leaf epidermis exhibits spatiotemporal variability.
Department of Biophysics and Morphogenesis of Plants, University of Silesia, Jagiellońska 28, Katowice, Poland.
Joanna
J
Elsner
Marek
M
Michalski
Dorota
D
Kwiatkowska
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation; D048430:Cell Shape; D048429:Cell Size; D016213:Cyclins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D019441:Plant Epidermis / Q000166:cytology / Q000235:genetics / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D013997:Time Factors
D029681:Arabidopsis Proteins; C496944:CycD3 protein, Arabidopsis; D016213:Cyclins