UPSC Monday Seminarseries 2025

9:00 tba

Title: tba

Supervisor: tba

9:30 Dhriti Singh

Title: Sweet shaping of Root System Architecture under water deficit

Supervisor: Johannes Hanson


Place: Lilla hörsalen KB.E3.01
Time: 9:00-10:00

Contact: Thomas Dobrenel, Anne Honsel

Are you new at UPSC?

We invite every newcomer at UPSC to participate in the Welcome Meeting. This meeting will be held twice per semester, four times per year and gives you important information about UPSC, how it is organised, who are your contact persons and will help you to find your way around at UPSC.

Please make sure to attend at least one meeting after your arrival at UPSC. We will serve fika for everyone participating.

We are looking forward to meeting you!

Johannes Hanson (Head of Department, UMU), Totte Niittylä (Head of Department, SLU), Ove Nilsson (Director of UPSC)

UPSC Cutting-Edge Seminar

Katharina Markmann
University of Würzburg, Germany

Title: Systemic control of and root architecture and symbiotic competence through mobile miRNAs

Host: Stephan Wenkel


Abstract:
Authors: Daniela Tsikou, Zhe Yan, Moritz Sexauer, Hemal Bhasin & Katharina Markmann

Legumes balance symbiotic interactions with nitrogen-fixing rhizobial bacteria via a systemic feedback system tightly controlling rates of bacterial infection and nodulation events. This host regulatory system, termed autoregulation of nodulation (AON), prevents nutritional misbalances and is key to maintaining the association at a mutualistic state. We identified a riboregulator, the micro RNA miR2111, that undergoes shoot-to-root translocation to control infection (1) through specific post-transcriptional regulation of the Kelch-repeat F-box gene TOO MUCH LOVE (TML), a root-acting repressor of infection and nodulation (2). Our results reveal miR2111 as a key systemic activator of symbiosis that maintains a susceptible default status in noninfected hosts. The regulon miR2111-TML is conserved across dicot land plant lineages, including the asymbiotic ruderal Arabidopsis thaliana. Plants adapt their root system architecure to soil nitrogen availability in a process called foraging. Our data suggest that apart from its role in symbiosis control, miR2111 acts as a mobile shoot signal translocating to the root in a nitrogen homeostasis-dependent manner to control lateral root formation (3). Comparative investigations in the model legume Lotus japonicus and Arabidopsis thaliana identify this regulon as an essential, evolutionarily stable factor in shoot dependent adaptation of root organ formation in response to nitrate availability in plants of divergent lifestyles (3).

(1) Tsikou et al. (2018) Science 362: 233-236
(2) Takahara et al. (2013) Plant & Cell Physiology 54: 433-447
(3) Sexauer et al. (2023) Nature Communications 14: 8083