Plants have evolved strategies to avoid shade and optimize the capture of sunlight. While some species are tolerant to shade, plants such as Arabidopsis thaliana are shade-intolerant and induce elongation of their hypocotyl to outcompete neighboring plants. We report the identification of a developmental module acting downstream of shade perception controlling vascular patterning. We show that Arabidopsis plants react to shade by increasing the number and types of water-conducting tracheary elements in the vascular cylinder to maintain vascular density constant. Mutations in genes affecting vascular patterning impair the production of additional xylem and also show defects in the shade-induced hypocotyl elongation response. Comparative analysis of the shade-induced transcriptomes revealed differences between wild type and vascular patterning mutants and it appears that the latter mutants fail to induce sets of genes encoding biosynthetic and cell wall modifying enzymes. Our results thus set the stage for a deeper understanding of how growth and patterning are coordinated in a dynamic environment.

中文翻译：

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光会影响避光反应中下胚轴的组织构图。

植物已经开发出避免遮阴并优化阳光捕获的策略。虽然某些物种可以耐荫，但拟南芥等植物却不耐荫，并导致其下胚轴伸长，从而胜过邻近植物。我们报告的发展模块的阴影控制血管图案的阴影感知下游的鉴定。我们显示拟南芥植物通过增加维管中水传导性气管元件的数量和类型来对阴影产生反应，以保持血管密度恒定。影响血管模式的基因突变会损害额外木质部的产生，并且还会在阴影诱导的下胚轴伸长反应中显示出缺陷。阴影诱导的转录组的比较分析揭示了野生型和维管构型突变体之间的差异，并且似乎后者突变体不能诱导编码生物合成和细胞壁修饰酶的基因集。因此，我们的结果为深入了解动态环境中的生长和图案协调方式奠定了基础。