Recruitment of bifunctional regulator thermospermine to methylated ribosomes directs xylem fate

Ko, Donghwi; Ruonala, Raili; Faille, Alexandre; Hellmann, Eva; Help, Hanna; Liu, Huili; Nielsen, Ronni; Haakonsson, Anders; De Diego, Nuria; Paatero, Anja; Shcherbii, Mariia V.; Stefanowicz, Karolina; Cavar Zeljkovic, Sanja; Drud Lundager Rasmussen, Tine; Novak, Ondrej; Bodi, Zsuzsanna; Eswaran, Gugan; Wybouw, Brecht; Bourdon, Matthieu; Urbez, Cristina; Liu, Xiaonan; Salokas, Kari; Ohman, Tiina; Waldie, Tanya; Toronen, Petri; El-Showk, Sedeer; Balcerowicz, Martin; Besnard, Fabrice; Liu, Xiaomin; Perkins, Patrick; Mazzoni-Putman, Serina; Vainonen, Julia P.; Sierla, Maija; Frilander, Mikko J.; Mandrup, Susanne; Vernoux, Teva; Ljung, Karin; Ferrando, Alejandro; Blazquez, Miguel A.; Holm, Liisa; Fray, Rupert; Varjosalo, Markku; Leyser, Ottoline; Paavilainen, Ville O.; Mahonen, Ari Pekka; Stepanova, Anna; Alonso, Jose; Heber, Steffen; Malinowski, Robert; Kirpekar, Finn; Warren, Alan J.; Helariutta, Yka

doi:10.1126/science.adx2867

Research article2026Peer reviewedOpen access

Recruitment of bifunctional regulator thermospermine to methylated ribosomes directs xylem fate

Ko, Donghwi; Ruonala, Raili; Faille, Alexandre; Hellmann, Eva; Help, Hanna; Liu, Huili; Nielsen, Ronni; Haakonsson, Anders; De Diego, Nuria; Paatero, Anja; Shcherbii, Mariia V.; Stefanowicz, Karolina; Cavar Zeljkovic, Sanja; Drud Lundager Rasmussen, Tine; Novak, Ondrej; Bodi, Zsuzsanna; Eswaran, Gugan; Wybouw, Brecht; Bourdon, Matthieu; Urbez, Cristina;
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Abstract

Polyamines are often associated with ribosomes and are thought to stabilize their integrity. In Arabidopsis, the polyamine thermospermine (tSpm) affects xylem cell fate. tSpm induces translation of SUPPRESSOR-OF-ACAULIS51 (SAC51) and SAC51-LIKEs (SACLs), which inhibit heterodimerization of the xylem development proteins LONESOME-HIGHWAY (LHW) and TARGET-OF-MONOPTEROS5. Here, we report a methyltransferase, OVERACHIEVER, that methylates the peptidyl transferase center of the 25S ribosomal RNA (rRNA). Residue m3U2952 promotes functional tSpm binding to a specific site connecting the P-site transfer RNA (tRNA) with rRNA residues in the peptidyl transferase center. This interaction enhances the translation of SACLs but inhibits that of LHW. Our study uncovers the dependency between a conserved rRNA base methylation and a polyamine in orchestrating cell fate decisions, highlighting a role for the ribosome chemical landscape in translational regulation.

Published in

Science
2026, volume: 391, number: 6786, pages: 694-699
Publisher: AMER ASSOC ADVANCEMENT SCIENCE

SLU Authors

Ljung, Karin
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences

UKÄ Subject classification

Genetics and Genomics
Cell Biology
Botany

Publication identifier

DOI: https://doi.org/10.1126/science.adx2867

Permanent link to this page (URI)

https://res.slu.se/id/publ/146318