Methyl 3-(4-hydroxyphenyl)propionate (MHPP) is a root exudate that functions as a nitrification inhibitor and as a modulator of the root system architecture (RSA) by inhibiting primary root (PR) elongation and promoting lateral root formation. However, the mechanism underlying MHPP-mediated modulation of the RSA remains unclear. Here, we report that MHPP inhibits PR elongation in Arabidopsis (Arabidopsis thaliana) by elevating the levels of auxin expression and signaling. MHPP induces an increase in auxin levels by up-regulating auxin biosynthesis, altering the expression of auxin carriers, and promoting the degradation of the auxin/indole-3-acetic acid family of transcriptional repressors. We found that MHPP-induced nitric oxide (NO) production promoted reactive oxygen species (ROS) accumulation in root tips. Suppressing the accumulation of NO or ROS alleviated the inhibitory effect of MHPP on PR elongation by weakening auxin responses and perception and by affecting meristematic cell division potential. Genetic analysis supported the phenotype described above. Taken together, our results indicate that MHPP modulates RSA remodeling via the NO/ROS-mediated auxin response pathway in Arabidopsis. Our study also revealed that MHPP significantly induced the accumulation of glucosinolates in roots, suggesting the diverse functions of MHPP in modulating plant growth, development, and stress tolerance in plants.

中文翻译：

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硝化抑制剂3-（4-羟基苯基）丙酸甲酯通过干扰通过NO / ROS途径的生长素信号传导来调节根系发育。

3-（4-羟苯基）丙酸甲酯（MHPP）是一种根系分泌物，通过抑制初级根（PR）伸长并促进侧根形成，从而充当硝化抑制剂和根系体系结构（RSA）的调节剂。但是，尚不清楚MHPP介导的RSA调节的基础机制。在这里，我们报告说，MHPP通过提高植物生长素的表达和信号传导水平抑制了拟南芥（Arabidopsis thaliana）中的PR伸长。MHPP通过上调植物生长素的生物合成，改变植物生长素的载体表达并促进植物生长素/吲哚-3-乙酸家族的转录抑制因子的降解来诱导植物生长素水平的升高。我们发现MHPP诱导的一氧化氮（NO）产生促进了根尖中活性氧（ROS）的积累。抑制NO或ROS的积累可通过减弱植物生长素的应答和感知力以及影响分生细胞分裂潜能来缓解MHPP对PR延长的抑制作用。遗传分析支持上述表型。两者合计，我们的结果表明，MHPP通过NO / ROS介导的拟南芥生长素应答途径调节RSA重塑。我们的研究还表明，MHPP显着诱导了芥子油苷在根中的积累，表明MHPP在调节植物生长，发育和胁迫耐受性方面具有多种功能。我们的结果表明，MHPP通过NO / ROS介导的拟南芥生长素应答途径调节RSA重塑。我们的研究还表明，MHPP显着诱导了芥子油苷在根中的积累，表明MHPP在调节植物生长，发育和胁迫耐受性方面具有多种功能。我们的结果表明，MHPP通过NO / ROS介导的拟南芥生长素应答途径调节RSA重塑。我们的研究还表明，MHPP显着诱导了芥子油苷在根中的积累，表明MHPP在调节植物生长，发育和胁迫耐受性方面具有多种功能。