Auxin-dependent post-translational regulation of MONOPTEROS in the Arabidopsis root

作者：Alex Cavalleri, Chiara Astori, Jekaterina Truskina, Mara Cucinotta, Etienne Farcot, Elina Chrysanthou, Xiaocai Xu, José M. Muiño, Kerstin Kaufmann, Martin M. Kater, Teva Vernoux, Dolf Weijers, Malcolm J. Bennett, Rahul Bhosale, Anthony Bishopp, Lucia Colombo · 发表于：Cell Reports · 年份：2024 · DOI：10.1016/j.celrep.2024.115083 · 被引用次数：14 · 研究领域：Plant Molecular Biology Research、Plant Reproductive Biology、Photosynthetic Processes and Mechanisms

Auxin plays a pivotal role in plant development by activating AUXIN RESPONSE FACTORs (ARFs). Under low auxin levels, ARF activity is inhibited by interacting with Aux/IAAs. Aux/IAAs are degraded when the cellular auxin concentration increases, causing the release of ARF inhibition. Here, we show that levels of the ARF5/MONOPTEROS (MP) protein are regulated in a cell-type-specific and isoform-dependent manner. We find that the stability of MP isoforms is differentially controlled depending on the auxin level. The canonical MP isoform is degraded by the proteasome in root tissues with low auxin levels. While auxin sharpens the MP localization domain in roots, it does not do so in ovules or embryos. Our research highlights a mechanism for providing spatial control of auxin signaling capacity. Together with recent advances in understanding the tissue-specific expression and post-transcriptional modification of auxin signaling components, these results provide insights into understanding how auxin can elicit so many distinct responses.