Diel Growth Cycle of Isolated Leaf Discs Analyzed with a Novel, High-Throughput Three-Dimensional Imaging Method Is Identical to That of Intact Leaves
Diel Growth Cycle of Isolated Leaf Discs Analyzed with a Novel, High-Throughput Three-Dimensional Imaging Method Is Identical to That of Intact Leaves
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DOI：
10.1104/pp.108.134486
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发表时间：
2009-03-01
期刊：
影响因子：
7.4
通讯作者：
Walter, Achim
中科院分区：
文献类型：
--
作者：
Biskup, Bernhard;Scharr, Hanno;Walter, Achim
双子叶植物叶片生长具有明显的昼夜（24小时）周期，这是由一个复杂的因素网络控制。这是一个悬而未决的问题，在何种程度上叶片生长动力学控制的远程或本地信号。为了解决这个问题，我们建立了一个立体成像系统，GROWSCREEN 3D，它量化的表面生长孤立的叶盘漂浮在营养液中的微量滴定板的威尔斯孔。对458片不同发育阶段的烟草叶片进行了切割、培养和相对生长速率分析。相机系统在叶盘阵列中自动移位;可视化和相机移位对于每个叶盘花费约12秒，导致连续大小分析的时间间隔为1.5小时。叶盘表现出与完整叶片相当的昼夜叶生长周期，但较弱的峰值生长活性。因此，可以得出结论，叶片生长的时间是由当地而不是由系统控制过程。这一结论得到了拟南芥（Arabidopsis thaliana）兰茨贝格直立野生型植物和无淀粉突变体的叶盘结果的支持。在夜间，利用短暂的淀粉导致增加的增长兰茨贝格直立野生型光盘相比，无淀粉1光盘。此外，当暴露于不同浓度的草甘膦时，叶盘生长的下降显示出立即的剂量依赖性反应。我们的研究结果表明，动态叶盘生长分析，因为我们在这里提出的是一个很有前途的方法来揭示内部和外部线索对双子叶植物叶片发育的影响。
Dicot leaves grow with pronounced diel (24-h) cycles that are controlled by a complex network of factors. It is an open question to what extent leaf growth dynamics are controlled by long-range or by local signals. To address this question, we established a stereoscopic imaging system, GROWSCREEN 3D, which quantifies surface growth of isolated leaf discs floating on nutrient solution in wells of microtiter plates. A total of 458 leaf discs of tobacco (Nicotiana tabacum) were cut at different developmental stages, incubated, and analyzed for their relative growth rates. The camera system was automatically displaced across the array of leaf discs; visualization and camera displacement took about 12 s for each leaf disc, resulting in a time interval of 1.5 h for consecutive size analyses. Leaf discs showed a comparable diel leaf growth cycle as intact leaves but weaker peak growth activity. Hence, it can be concluded that the timing of leaf growth is regulated by local rather than by systemic control processes. This conclusion was supported by results from leaf discs of Arabidopsis (Arabidopsis thaliana) Landsberg erecta wild-type plants and starch-free1 mutants. At night, utilization of transitory starch leads to increased growth of Landsberg erecta wild-type discs compared with starch-free1 discs. Moreover, the decrease of leaf disc growth when exposed to different concentrations of glyphosate showed an immediate dose-dependent response. Our results demonstrate that a dynamic leaf disc growth analysis as we present it here is a promising approach to uncover the effects of internal and external cues on dicot leaf development.