Monocot root systems comprise a large number of lateral roots to allow them to survive and colonize land. Auxin signaling pathways centered on Aux/IAA play a crucial role in lateral root development. However, in non-model monocot plants, the effects of Aux/IAA on lateral root initiation and number remain largely unknown. The present study transformed PheIAA17, a member of the Aux/IAA family of Moso bamboo, into rice and found that it significantly drove plants to produce lateral roots and improved the rooting rate. Quantitative experiments showed that PheIAA17 overexpression significantly affected the expression of ARF family members. Phylogenetic and promoter analyses indicate that PheARF3-2 belongs to class B ARF, and the promoter region contains auxin response elements. The results of yeast one-hybrid and dual-luciferase reporter assays confirmed that PheIAA17 bound specific fragments of the PheARF3-2 promoter to repress its transcriptional activity. Y2H and BiFC assay have shown that PheIAA17 and PheIAA30-3 could physically interact in vitro and in vivo. Taken together, this study reports a new molecular module centered on PheIAA17, which directs plants to alter root morphology through an increase in lateral roots.

中文翻译：

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以PheIAA17为核心的分子模块显着促进侧根萌发


单子叶植物根系包含大量侧根，使它们能够生存并在土地上定居。以 Aux/IAA 为中心的生长素信号通路在侧根发育中发挥着至关重要的作用。然而，在非模式单子叶植物中，Aux/IAA 对侧根萌生和数量的影响仍然很大程度上未知。本研究将毛竹Aux/IAA家族成员PheIAA17转化到水稻中，发现其显着促进植物产生侧根并提高生根率。定量实验表明PheIAA17过表达显着影响ARF家族成员的表达。系统发育和启动子分析表明PheARF3-2属于B类ARF，启动子区域含有生长素响应元件。酵母单杂交和双荧光素酶报告基因测定的结果证实，PheIAA17 结合 PheARF3-2 启动子的特定片段以抑制其转录活性。 Y2H 和 BiFC 测定表明 PheIAA17 和 PheIAA30-3 可以在体外和体内发生物理相互作用。总而言之，这项研究报告了一个以 PheIAA17 为中心的新分子模块，它指导植物通过增加侧根来改变根形态。