Department of Biophysics and Morphogenesis of Plants, University of Silesia, Jagiellońska 28, Katowice, Poland.
Ann Bot. 2012 Apr;109(5):897-910. doi: 10.1093/aob/mcs005. Epub 2012 Feb 2.
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.
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.
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.
Growth of leaf epidermis exhibits spatiotemporal variability.
扩张的双子叶叶表皮是具有不同身份、大小和分化阶段的细胞马赛克。在此，我们检验了以下假设：在这样的细胞马赛克中，生长是异质的，并且随时间变化，并且这种异质性不依赖于细胞周期调控本身。
利用野生型拟南芥和三重 cyclinD3 突变体植物扩张叶片中的连续复制品，结合使用 epi-fluorescence 显微镜进行倍性估计，跟踪个体细胞的形状、大小和生长。
单个表皮细胞或小细胞群的相对生长速率在面积上相差几倍，并且随时间变化。这种空间和时间变化与细胞或细胞核的大小无关。单个细胞内的形状变化和生长也是异质的：在不同的壁部分中，垂直壁的波动出现在不同的时间；与不同邻居接触的细胞周边部分以不同的速率生长。这种变化与细胞生长各向异性无关。这种变异性是野生型和 cycD3 的典型特征。
叶片表皮的生长表现出时空可变性。
