WRKY transcription factors and ethylene signaling modify root growth during the shade-avoidance response
WRKY transcription factors and ethylene signaling modify root growth during the shade-avoidance response
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DOI：
10.1093/plphys/kiab493
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发表时间：
2022-02-04
期刊：
影响因子：
7.4
通讯作者：
Pedmale, Ullas, V
中科院分区：
文献类型：
--
作者：
Rosado, Daniele;Ackermann, Amanda;Pedmale, Ullas, V
不耐荫的植物迅速拉长茎、枝和叶柄，与邻近的植被竞争，最大限度地利用阳光进行光合作用。这种快速的生长适应，被称为避荫反应（SAR），是有代价的：减少生物量，作物产量和根系生长。下胚轴伸长在SAR过程中的机制的理解已经取得了重大进展，但是，根生长抑制的分子解释还没有很好地理解。在这里，我们探讨了低红光诱导的SAR的机制：远红光限制主根和侧根（LR）的生长。通过分析全基因组转录组，我们确定了一个核心组的拟南芥（Arabidopsis thaliana）和番茄（Solanum lycopersicum）幼苗根的阴影诱导基因在阴影中生长。非生物和生物应激源也诱导许多这些遮荫诱导的基因，并主要由WRKY转录因子调节。相应地，大多数WRKY基因也属于遮荫诱导基因。使用转基因的这些阴影诱导WRKYs的功能分析表明，它们的作用基本上是限制主根和LR生长在阴影中，迷人的是，他们没有影响下胚轴伸长。同样，我们还发现，乙烯激素信号是必要的限制根生长在阴凉处。我们认为，在SAR期间，遮荫诱导WRKY 26，45和75，乙烯重编程基因表达在根中限制其生长和发展。低红色：远红色阴影诱导基因调控WRKY转录因子和乙烯，限制主根和侧根的生长。
Shade-intolerant plants rapidly elongate their stems, branches, and leaf stalks to compete with neighboring vegetation, maximizing sunlight capture for photosynthesis. This rapid growth adaptation, known as the shade-avoidance response (SAR), comes at a cost: reduced biomass, crop yield, and root growth. Significant progress has been made on the mechanistic understanding of hypocotyl elongation during SAR; however, the molecular interpretation of root growth repression is not well understood. Here, we explore the mechanisms by which SAR induced by low red:far-red light restricts primary and lateral root (LR) growth. By analyzing the whole-genome transcriptome, we identified a core set of shade-induced genes in roots of Arabidopsis (Arabidopsis thaliana) and tomato (Solanum lycopersicum) seedlings grown in the shade. Abiotic and biotic stressors also induce many of these shade-induced genes and are predominantly regulated by WRKY transcription factors. Correspondingly, a majority of WRKY genes were among the shade-induced genes. Functional analysis using transgenics of these shade-induced WRKYs revealed that their role is essentially to restrict primary root and LR growth in the shade; captivatingly, they did not affect hypocotyl elongation. Similarly, we also found that ethylene hormone signaling is necessary for limiting root growth in the shade. We propose that during SAR, shade-induced WRKY26, 45, and 75, and ethylene reprogram gene expression in the root to restrict its growth and development.Low red:far-red shade induces genes in roots regulated by WRKY transcription factors and ethylene, restricting primary and lateral root growth.