Brassinosteroids (BRs) are well-characterized growth hormones that are critical for plant growth, development, and productivity. Genetic and molecular studies have revealed the key components of BR biosynthesis and signaling pathways. The membrane-localized BR signaling receptor, BRASSINOSTEROID INSENSITIVE1 (BRI1) binds directly to its ligand and initiates series of signaling events that led to the activation of BR transcriptional regulators, BRASSINAZOLE RESISTANT1 (BZR1) and BRI1-ETHYL METHANESULFONATE-SUPPRESSOR1 (BES1/BZR2) to regulate the cellular processes. Insights from Arabidopsis research revealed tissue and cell type-specific roles of BR in controlling cell elongation and maintenance of stem cell niche in roots. More recently, BRs have gained much attention in regulating the root growth during nutrient deficiency such as nitrogen, phosphorus, and boron. Differential distribution of nutrients in the rhizosphere alters BR hormone levels and signaling to reprogram spatial distribution of root system architecture (RSA) such as a change in primary root growth, lateral root numbers, length, and angle, root hair formation and elongation. These morpho-physiological changes in RSA are also known as an adaptive root trait or foraging response of the plant. In this review, we highlight the role of BRs in regulating RSA to increase root foraging response during fluctuating nutrient availability.

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评论：油菜素类固醇在营养觅食中的新作用

油菜素类固醇 (BRs) 是表征良好的生长激素，对植物生长、发育和生产力至关重要。遗传和分子研究揭示了 BR 生物合成和信号通路的关键组成部分。膜定位的 BR 信号受体 BRASSINOSTEROID INSENSITIVE1 (BRI1) 直接与其配体结合并启动一系列信号事件，导致 BR 转录调节因子、BRASSINAZOLE RESISTANT1 (BZR1) 和 BRI1-ETHYL METHANESULFONATE-SUPPRESSOR1/BRI1 ) 来调节细胞过程。拟南芥研究的见解揭示了 BR 在控制细胞伸长和维持根中干细胞生态位方面的组织和细胞类型特异性作用。最近，BRs 在调节营养缺乏（如氮、磷和硼。根际营养物质的差异分布会改变 BR 激素水平和信号，以重新编程根系结构 (RSA) 的空间分布，例如初级根生长、侧根数、长度和角度、根毛形成和伸长的变化。RSA 的这些形态生理变化也被称为植物的适应性根性状或觅食反应。在这篇综述中，我们强调了 BR 在调节 RSA 以在养分可用性波动期间增加根觅食反应中的作用。根毛形成和伸长。RSA 的这些形态生理变化也被称为植物的适应性根性状或觅食反应。在这篇综述中，我们强调了 BR 在调节 RSA 以在养分可用性波动期间增加根觅食反应中的作用。根毛形成和伸长。RSA 的这些形态生理变化也被称为植物的适应性根性状或觅食反应。在这篇综述中，我们强调了 BR 在调节 RSA 以在养分可用性波动期间增加根觅食反应中的作用。