Alternative Splicing Generates a MONOPTEROS Isoform Required for Ovule Development

第一作者：Mara Cucinotta

第一单位：米兰大学

通讯作者：Lucia Colombo

 Abstract 

背景-auxin：The plant hormone auxin is a fundamental regulator of organ patterning and development that regulates gene expression via the canonical AUXIN RESPONSE FACTOR (ARF) and AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) combinatorial system.

背景-ARF-Aux/IAA：ARF and Aux/IAA factors interact, but at high auxin concentrations, the Aux/IAA transcriptional repressor is degraded, allowing ARF-containing complexes to activate gene expression.

背景-ARF5：ARF5/MONOPTEROS (MP) is an important integrator of auxin signaling in Arabidopsis development and activates gene transcription in cells with elevated auxin levels.

主要发现：Here, we show that in ovules, MP is expressed in cells with low levels of auxin and can activate the expression of direct target genes.

结果1-可变剪切：We identified and characterized a splice variant of MP that encodes a biologically functional isoform that lacks the Aux/IAA interaction domain.

结果2-ARF5异构体：This MP11ir isoform was able to complement inflorescence, floral, and ovule developmental defects in mp mutants, suggesting that it was fully functional.

结论：Our findings describe a novel scenario in which ARF post-transcriptional regulation controls the formation of an isoform that can function as a transcriptional activator in regions of subthreshold auxin concentration.

 通讯作者 

doi: https://doi.org/10.1016/j.cub.2020.11.026

Journal: Current Biology

Published date: Dec 03, 2020