Key message

ARF4-regulated shoot regeneration through competing with ARF5 for the interaction with IAA12.

Abstract

Plant possess the ability to regenerate shoot meristem and subsequent the whole individual. This process is the foundation for in vitro propagation and genetic engineering and provides a system for studying fundamental biological questions, such as hormonal signaling. Auxin response factor (ARF) family transcription factors are critical components of auxin signaling pathway that regulate the transcription of target genes. To date, the mechanisms underlying the functions of class-B ARFs which act as transcription repressors remains unclear. In this study, we found that ARF4, the transcriptional repressor, was involved in regulating shoot regeneration. ARF4 interacted with auxin/Indole-3-Acetic-Acid12 (IAA12). The expression signals of ARF4 displayed a dynamic pattern similar with those of ARF5 and IAA12 during shoot meristem formation. Enhanced expression of IAA12 compromised the shoot regeneration capacity. Induced expression of ARF4 complemented the regeneration phenotype of IAA12-overexpression but did not rescued the defects in the arf5 mutant, mp-S319. Further analysis revealed that ARF4 competed with ARF5 for the interaction with IAA12. The results indicate that ARF4-regulated shoot regeneration through cooperating with ARF5 and IAA12. Our findings provided new information for deciphering the function of class-B ARFs.

中文翻译：

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ARF4 通过与 ARF5 和 IAA12 协调来调节枝条再生

关键信息

ARF4 通过与 ARF5 竞争与 IAA12 的相互作用来调节枝条再生。

抽象的

植物具有再生芽分生组织和随后整个个体的能力。该过程是体外繁殖和基因工程的基础，并为研究基本生物学问题（如激素信号传导）提供了一个系统。生长素反应因子（ARF）家族转录因子是调节靶基因转录的生长素信号通路的重要组成部分。迄今为止，作为转录抑制因子的 B 类 ARF 的功能机制仍不清楚。在这项研究中，我们发现转录抑制因子 ARF4 参与调节枝条再生。ARF4 与生长素/Indole-3-Acetic-Acid12 (IAA12) 相互作用。ARF4的表达信号在芽分生组织形成过程中表现出与ARF5和IAA12相似的动态模式。IAA12损害了枝条再生能力。ARF4 的诱导表达补充了IAA12过表达的再生表型，但没有挽救arf5突变体mp-S319中的缺陷。进一步分析表明，ARF4 与 ARF5 竞争与 IAA12 的相互作用。结果表明，ARF4通过与ARF5和IAA12的协同作用来调控枝条再生。我们的研究结果为破译 B 类 ARF 的功能提供了新的信息。