# Rewiring of LEUNIG_HOMOLOG interaction networks marks regulatory shifts from meristem to organ growth in Arabidopsis flowers

## TL;DR

The study shows how the LUH protein interacts with different partners at different stages of flower development in Arabidopsis, helping coordinate growth and pattern formation.

## Contribution

The study reveals stage-specific interactions of LUH that coordinate growth and patterning during Arabidopsis flower development.

## Key findings

- LUH interacts with distinct transcription factors and chromatin proteins during different developmental stages.
- LUH activity shifts from meristem-focused to organogenesis-oriented as flowers develop.
- LUH and LUG modulate gene expression essential for floral organ patterning.

## Abstract

LEUNIG (LUG) and LEUNIG_HOMOLOG (LUH) are Groucho/Tup1‐type transcriptional co‐regulators in Arabidopsis thaliana that act redundantly across multiple developmental and environmental response pathways. Their specific contributions to flower development, however, have remained unclear due to embryonic lethality of double mutants. Here, we show that LUH associates with distinct sets of transcription factors and chromatin‐associated proteins in a developmentally dynamic manner. Chromatin occupancy and protein interactions shift from a meristem‐focused network during early floral patterning to an organogenesis‐oriented state as primordia initiate and expand. Reduced promoter‐proximal LUH binding coincides with this proliferative phase, suggesting a transient reconfiguration of LUH activity. By later stages, LUH activity is amplified alongside organ differentiation programs. Together with LUG, LUH modulates gene expression programs that are essential for establishing floral organ patterning. These findings reveal how dynamic co‐regulator assemblies contribute to the temporal coordination of growth and spatial pattern formation in Arabidopsis flowers.

This study reveals that the transcriptional co‐regulator LUH interacts with distinct transcriptional and chromatin‐associated partners in a stage‐specific manner during flower development. By linking the dynamic activity of LUH to spatial patterning and organ identity, we provide new mechanistic insights into how Arabidopsis floral morphogenesis is coordinated by the LUH gene regulatory network.