在这项研究中，研究小组报道了干分枝刺激如何触发根核中ROS水平的快速变化，从而触发生长素抑制蛋白IAA3的氧化还原依赖性多聚。IAA3特定半胱氨酸残基的突变破坏了氧化还原介导的多聚和与共抑制因子TPL的相互作用，从而减弱了IAA3介导的靶基因抑制。其他AUX/IAA蛋白在氧化还原介导的多聚合中也有所不同，揭示了一种将细胞氧化还原状态的动态变化与生长素信号传导联系起来的调节机制。他们的研究揭示了活性氧、生长素和水分有效性如何交叉并形成根适应性反应，从而维持植物的表型可塑性。
研究人员表示，活性氧是植物适应干旱等环境胁迫的关键信号。根系对瞬时水分缺乏的反应是通过驯化性的干枝反应暂时停止分枝。
附：英文原文
Title: Redox-regulated Aux/IAA multimerization modulates auxin responses
Author: Dipan Roy, Poonam Mehra, Lisa Clark, Vaishnavi Mukkawar, Kevin Bellande, Raquel Martin-Arevalillo, Srayan Ghosh, Kishor D. Ingole, Prakash Kumar Bhagat, Adrian Brown, Kawinnat Sue-ob, Andrew Jones, Joop E. M. Vermeer, Teva Vernoux, Kathryn Lilley, Phil Mullineaux, Ulrike Bechtold, Malcolm J. Bennett, Ari Sadanandom
Issue&Volume: 2025-06-12
Abstract: Reactive oxygen species function as key signals in plant adaptation to environmental stresses like drought. Roots respond to transient water unavailability by temporarily ceasing branching through the acclimative response xerobranching. In this study, we report how a xerobranching stimulus triggers rapid changes of ROS levels in root nuclei, triggering redox-dependent multimerization of the auxin repressor protein IAA3. Mutations in specific cysteine residues of IAA3 disrupt redox-mediated multimerization and interaction with co-repressor TPL, thereby attenuating IAA3 mediated target gene repression. Other AUX/IAA proteins also vary in their redox mediated multimerization, revealing a regulatory mechanism that connects dynamic changes in cellular redox status to auxin signaling. Our study reveals how ROS, auxin and water availability intersect and shape root adaptive responses, thereby maintaining phenotypic plasticity in plants.
DOI: adu1470
Source: https://www.science.org/doi/10.1126/science.adu1470