Light-dependent activation of TCP4 by the GATA25 transcription factor promotes petiole and hypocotyl elongation in Arabidopsis thaliana
- 1Kyungpook National University
Abstract
Plants coordinate cell elongation with the daily light/dark cycle, an important adaptive strategy for optimizing growth under changing environmental conditions. However, the transcriptional mechanisms linking light signals to plant developmental growth remain poorly understood. In this study, we identified the GATA25 transcription factor as a regulator of petiole and hypocotyl elongation in response to light and photoperiod. Overexpression of GATA25 in Arabidopsis thaliana increased petiole and hypocotyl lengths and elevated TCP4 transcript levels. We demonstrated that GATA25 directly binds to the promoter of TCP4 and activates its transcription using transcriptional activation analysis, a glucocorticoid receptor-based inducible system, chromatin immunoprecipitation, and electrophoretic mobility shift assays. Furthermore, yeast two-hybrid assay and bimolecular fluorescence complementation analyses showed that GATA25 physically interacts with the E3 ubiquitin ligase COP1. Notably, overexpression of GATA25 did not increase TCP4 transcript levels in dark conditions, suggesting that GATA25 activity is suppressed in dark conditions. Based on these findings, we propose a model in which GATA25 is destabilized by COP1 in dark conditions, restricting TCP4 activation to the light conditions. Taken together, these findings provide a framework for understanding how the daily light/dark cycle regulates cell elongation in a photoperiod-dependent manner through the GATA25-TCP4 module.
Related
- Iron Excess Stress Promotes Adventitious Root Formation at the Root–Hypocotyl Junction in Arabidopsis
- Molecular mechanism of albicidin-dependent transcription activation by the antibiotic resistance factor AlbA
- Recognition-dependent activation of the Arabidopsis RRS1-R/RPS4 TIR-NLR immune receptor pair
- Tyrosine-sulfated peptide-induced flavonol biosynthesis controls elongation and differentiation in Arabidopsis primary root
- The core interaction network of transcription elongation factors is broadly maintained across diverse bacteria
BibTeX
@misc{kim2026lightdependent,
title = {{Light-dependent activation of TCP4 by the GATA25 transcription factor promotes petiole and hypocotyl elongation in Arabidopsis thaliana}},
author = {K. Kim and J. Shin and W.-C. Kim},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.19.760297},
url = {https://www.biorxiv.org/content/10.64898/2026.10.19.760297v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Light-dependent activation of TCP4 by the GATA25 transcription factor promotes petiole and hypocotyl elongation in Arabidopsis thaliana
AU - K. Kim
AU - J. Shin
AU - W.-C. Kim
PY - 2026
DA - 2026/10/19
PB - bioRxiv
DO - 10.64898/2026.10.19.760297
UR - https://www.biorxiv.org/content/10.64898/2026.10.19.760297v1
AB - Plants coordinate cell elongation with the daily light/dark cycle, an important adaptive strategy for optimizing growth under changing environmental conditions. However, the transcriptional mechanisms linking light signals to plant developmental growth remain poorly understood. In this study, we identified the GATA25 transcription factor as a regulator of petiole and hypocotyl elongation in response to light and photoperiod. Overexpression of GATA25 in Arabidopsis thaliana increased petiole and hypocotyl lengths and elevated TCP4 transcript levels. We demonstrated that GATA25 directly binds to the promoter of TCP4 and activates its transcription using transcriptional activation analysis, a glucocorticoid receptor-based inducible system, chromatin immunoprecipitation, and electrophoretic mobility shift assays. Furthermore, yeast two-hybrid assay and bimolecular fluorescence complementation analyses showed that GATA25 physically interacts with the E3 ubiquitin ligase COP1. Notably, overexpression of GATA25 did not increase TCP4 transcript levels in dark conditions, suggesting that GATA25 activity is suppressed in dark conditions. Based on these findings, we propose a model in which GATA25 is destabilized by COP1 in dark conditions, restricting TCP4 activation to the light conditions. Taken together, these findings provide a framework for understanding how the daily light/dark cycle regulates cell elongation in a photoperiod-dependent manner through the GATA25-TCP4 module.
ER -