Can meristematic activity determine variation in leaf size and elongation rate among four Poa species?: A kinematic study
Can meristematic activity determine variation in leaf size and elongation rate among four Poa species?: A kinematic study
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DOI：
10.1104/pp.124.2.845
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发表时间：
2000-10-01
期刊：
影响因子：
7.4
通讯作者：
Lambers, H
中科院分区：
文献类型：
--
作者：
Fiorani, F;Beemster, GTS;Lambers, H
研究了四种早熟禾最终叶大小的遗传变异。它们生活在不同的海拔。最小种(高山早熟禾)主茎的平均末叶长度仅为最大种(早熟禾)的一半，与叶片伸长速率相关，但与叶片伸长时间无关。叶片伸长速率较快与(A)较大的细胞扩张区和(B)分生组织中较快的细胞产生速率有关，这反过来又是由于分裂细胞的数量较多，而所有物种的平均细胞分裂速率非常相似(除早熟禾外)。我们还发现，在所有物种的分生组织中，增殖分数都等于1。值得注意的是，在叶片生长较慢的物种中，细胞扩张率往往较高。我们通过比较空间和物质的观点对结果进行了讨论，这导致了对细胞分裂作用的不同解释。尽管目前的数据没有严格地证明这一点，但它们强烈表明，细胞分裂在决定目前四种早熟禾之间生长速度的差异方面发挥了调节作用。
We studied inherent variation in final leaf size among four Poa spp. that live at different elevations. The average final length of leaf 7 of the main stem of the smallest species (Poa alpina) was only one-half that of the largest species (Poa trivialis); it was correlated with leaf elongation rate, but not with the duration of leaf elongation. A faster rate of leaf elongation rate was associated with (a) larger size of the zone of cell expansion, and (b) faster rates of cell production (per cell file) in the meristem, which in turn were due to greater numbers of dividing cells, whereas average cell division rates were very similar for all species (except Poa annua). Also we found that the proliferative fraction equaled 1 throughout the meristem in all species. It was remarkable that rates of cell expansion tended to be somewhat higher in the species with slower growing leaves. We discuss the results by comparing the spatial and material viewpoints, which lead to different interpretations of the role of cell division. Although the presented data do not strictly prove it, they strongly suggest a regulatory role for cell division in determining differences in growth rate among the present four Poa spp.