Phytochrome B inhibits darkness‐induced hypocotyl adventitious root formation by stabilizing IAA14 and suppressing ARF7 and ARF19

第一作者：Qian‐Qian Li

第一单位：中科院分子植物科学卓越创新中心

通讯作者：Dai‐Yin Chao

 Abstract 

背景回顾：Adventitious roots (ARs) are an important root type for plants and display a high phenotypic plasticity in response to different environmental stimuli.

研究基础：Previous studies found that dark‐light transition can trigger AR formation from the hypocotyl of etiolated Arabidopsis thaliana, which was used as model for identification of regulators of AR biogenesis.

提出问题：However, the central regulatory machinery for darkness‐induced hypocotyl AR (HAR) remains elusive.

主要研究：Here, we report that photoreceptors suppress HAR biogenesis through regulating the molecular module essential for lateral roots.

结果1-HARs与光受体：We found that hypocotyls embedded in soil or in continuous darkness are able to develop HARs, wherein photoreceptors act as negative regulators.

结果2-创伤诱导的ARs与黑暗诱导的HARs：Distinct from wound‐induced ARs that require WOX11 and WOX12, darkness‐induced HARs are fully dependent on ARF7, ARF19, WOX5/7 and LBD16.

结果3-PHYB-IAA14-ARF7/19-HARs：Further studies established that PHYB interacts with IAA14, ARF7 and ARF9. The interactions stabilize IAA14 and inhibit the transcriptional activities of ARF7 and ARF19 and thus suppress biogenesis of darkness‐induced HARs.

结论：This finding not only revealed the central machinery controlling HAR biogenesis but also illustrated that AR formation could be initiated by multiple pathways.

 摘  要 

对于植物来说，不定根（AR）是一种重要的根的类型，并且对于不同的环境刺激，表现出高度的表型可塑性。先前的研究发现，黑暗-光照转变会诱导黄化拟南芥的下胚轴形成不定根，该系统被用作鉴定不定根生物发生的模型。但是，黑暗诱导的下胚轴不定根（HAR）的核心调控机制仍然不清楚。本文中，作者发现光受体通过调控对于侧根必要的分子模块抑制HAR的生物发生。作者发现下胚轴埋在土壤中或在持续黑暗中能够形成HARs，其中光感受器充当负调控因子。创伤诱导的AR形成需要WOX11和WOX12的参与，而黑暗诱导的HARs则完全依赖于ARF7、ARF19、WOX5/7以及LBD16。进一步的研究发现PHYB与IAA14、ARF7以及ARF9互作。这些互作能够稳定IAA14蛋白，抑制ARF7和ARF19的转录活性，从而抑制黑暗诱导的HARs形成。本文的研究不仅揭示了控制HAR生物发生的核心调控机制，还表明可能会有多个调控通路来起始AR的形成。

 通讯作者 

doi: https://doi.org/10.1111/tpj.15142

Journal: the plant journal

First Published: Dec 23, 2020