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Systematic analyses of the MIR172 family members of Arabidopsis define their distinct roles in regulation of APETALA2 during floral transition
MicroRNAs (miRNAs) play important roles in regulating flowering and reproduction of angiosperms. Mature miRNAs are encoded by multiple MIRNA genes that can differ in their spatiotemporal activities and their contributions to gene regulatory networks, but the functions of individual miRNA genes are poorly defined. Ó’Maoiléidigh et al. functionally analyzed the activity of all five Arabidopsis thaliana MIR172 genes, which encode miR172 and promote the floral transition by inhibiting the accumulation of APETALA2 (AP2) and APETALA2-LIKE (AP2-LIKE) transcription factors. Through genome editing and detailed confocal microscopy, the authors show that the activity of miR172 at the shoot apex is encoded by three MIR172 genes, is critical for floral transition of the shoot meristem under noninductive photoperiods, and reduces accumulation of AP2 and TARGET OF EAT2 (TOE2), an AP2-LIKE transcription factor, at the shoot meristem. The study presents a genetic framework for the depletion of AP2 and AP2-LIKE transcription factors at the shoot apex during floral transition and demonstrates that this plays a central role in floral induction. The image shows a confocal micrograph of the inflorescence of a plant in which the MIR172B gene has been replaced by a gene encoding the fluorescent protein Venus, grown for 19 days under long-day conditions. Green indicates the Venus protein (and therefore normal site of expression of MIR172B); magenta shows staining of plant cell walls by the Renaissance dye.
Image Credit: Diarmuid Ó’Maoiléidigh
Citation: (2021) PLoS Biology Issue Image | Vol. 19(2) March 2021. PLoS Biol 19(2): ev19.i02. https://doi.org/10.1371/image.pbio.v19.i02
Published: March 9, 2021
Copyright: © 2021 . This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
MicroRNAs (miRNAs) play important roles in regulating flowering and reproduction of angiosperms. Mature miRNAs are encoded by multiple MIRNA genes that can differ in their spatiotemporal activities and their contributions to gene regulatory networks, but the functions of individual miRNA genes are poorly defined. Ó’Maoiléidigh et al. functionally analyzed the activity of all five Arabidopsis thaliana MIR172 genes, which encode miR172 and promote the floral transition by inhibiting the accumulation of APETALA2 (AP2) and APETALA2-LIKE (AP2-LIKE) transcription factors. Through genome editing and detailed confocal microscopy, the authors show that the activity of miR172 at the shoot apex is encoded by three MIR172 genes, is critical for floral transition of the shoot meristem under noninductive photoperiods, and reduces accumulation of AP2 and TARGET OF EAT2 (TOE2), an AP2-LIKE transcription factor, at the shoot meristem. The study presents a genetic framework for the depletion of AP2 and AP2-LIKE transcription factors at the shoot apex during floral transition and demonstrates that this plays a central role in floral induction. The image shows a confocal micrograph of the inflorescence of a plant in which the MIR172B gene has been replaced by a gene encoding the fluorescent protein Venus, grown for 19 days under long-day conditions. Green indicates the Venus protein (and therefore normal site of expression of MIR172B); magenta shows staining of plant cell walls by the Renaissance dye.
Image Credit: Diarmuid Ó’Maoiléidigh