RAP2.6 negatively regulates Arabidopsis submergence tolerance through GSNOR1-dependent redox and hormonal signaling
- 1Department of Applied Biosciences, College of Agriculture & Life Science, Kyungpook National University, Daegu 41944, Korea
Abstract
Group VII ETHYLENE RESPONSE FACTORs (ERFVIIs) are central regulators of plant responses to oxygen deprivation. However, the contributions of many other APETALA2 (AP2)/ERF transcription factors to hypoxia and flooding responses remain poorly understood. Here, we identify the group X ERF transcription factor RAP2.6 as a negative regulator of submergence tolerance in Arabidopsis thaliana. RAP2.6 expression declined under hypoxia, and plants overexpressing RAP2.6 exhibited reduced survival following dark submergence, whereas the rap2.6-1 loss-of-function mutant showed enhanced tolerance to submergence, hypoxia, and ethanol treatment. Enhanced tolerance of rap2.6-1 was associated with reduced membrane injury, maintenance of photosynthetic pigments and soluble sugars, and extensive metabolic remodeling. RAP2.6 overexpression altered nitric oxide (NO), S-nitrosothiol (SNO), and ethylene accumulation during submergence and was associated with greater oxidative damage and enhanced abscisic acid (ABA)-responsive gene expression. Genetic analyses using S-NITROSOGLUTATHIONE (GSNO) REDUCTASE 1 (GSNOR1) gain- and loss-of-function backgrounds demonstrated that GSNOR1-dependent GSNO homeostasis strongly modified RAP2.6-dependent submergence responses. Increased GSNOR1 activity suppressed the submergence-sensitive phenotype of RAP2.6-overexpressing plants, reduced nitro-oxidative stress, and restored carbohydrate reserves, whereas loss of GSNOR1 activity abolished the enhanced tolerance of rap2.6-1. GSNOR1 also modified RAP2.6-dependent expression of genes associated with oxygen sensing and ABA signaling, while its protective effect was not explained solely by changes in ethylene accumulation. Together, these findings identify RAP2.6 as a regulatory component of the low-oxygen response and reveal a functional interaction between RAP2.6 and GSNOR1-dependent redox signaling that coordinates plant hormonal, metabolic, and oxidative responses during submergence.
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BibTeX
@misc{das2026rap26,
title = {{RAP2.6 negatively regulates Arabidopsis submergence tolerance through GSNOR1-dependent redox and hormonal signaling}},
author = {A. K. Das and M. G. Mostofa and D.-S. Lee and R. A. Mahmood and R. Alam and A. Hussain and N. J. Methela and Y.-J. Woo and S. Sultana and C.-W. Park and B.-G. Mun and I.-j. Lee and S. Kim and B.-W. Yun},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.25.761742},
url = {https://www.biorxiv.org/content/10.64898/2026.10.25.761742v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - RAP2.6 negatively regulates Arabidopsis submergence tolerance through GSNOR1-dependent redox and hormonal signaling
AU - A. K. Das
AU - M. G. Mostofa
AU - D.-S. Lee
AU - R. A. Mahmood
AU - R. Alam
AU - A. Hussain
AU - N. J. Methela
AU - Y.-J. Woo
AU - S. Sultana
AU - C.-W. Park
AU - B.-G. Mun
AU - I.-j. Lee
AU - S. Kim
AU - B.-W. Yun
PY - 2026
DA - 2026/10/25
PB - bioRxiv
DO - 10.64898/2026.10.25.761742
UR - https://www.biorxiv.org/content/10.64898/2026.10.25.761742v1
AB - Group VII ETHYLENE RESPONSE FACTORs (ERFVIIs) are central regulators of plant responses to oxygen deprivation. However, the contributions of many other APETALA2 (AP2)/ERF transcription factors to hypoxia and flooding responses remain poorly understood. Here, we identify the group X ERF transcription factor RAP2.6 as a negative regulator of submergence tolerance in Arabidopsis thaliana. RAP2.6 expression declined under hypoxia, and plants overexpressing RAP2.6 exhibited reduced survival following dark submergence, whereas the rap2.6-1 loss-of-function mutant showed enhanced tolerance to submergence, hypoxia, and ethanol treatment. Enhanced tolerance of rap2.6-1 was associated with reduced membrane injury, maintenance of photosynthetic pigments and soluble sugars, and extensive metabolic remodeling. RAP2.6 overexpression altered nitric oxide (NO), S-nitrosothiol (SNO), and ethylene accumulation during submergence and was associated with greater oxidative damage and enhanced abscisic acid (ABA)-responsive gene expression. Genetic analyses using S-NITROSOGLUTATHIONE (GSNO) REDUCTASE 1 (GSNOR1) gain- and loss-of-function backgrounds demonstrated that GSNOR1-dependent GSNO homeostasis strongly modified RAP2.6-dependent submergence responses. Increased GSNOR1 activity suppressed the submergence-sensitive phenotype of RAP2.6-overexpressing plants, reduced nitro-oxidative stress, and restored carbohydrate reserves, whereas loss of GSNOR1 activity abolished the enhanced tolerance of rap2.6-1. GSNOR1 also modified RAP2.6-dependent expression of genes associated with oxygen sensing and ABA signaling, while its protective effect was not explained solely by changes in ethylene accumulation. Together, these findings identify RAP2.6 as a regulatory component of the low-oxygen response and reveal a functional interaction between RAP2.6 and GSNOR1-dependent redox signaling that coordinates plant hormonal, metabolic, and oxidative responses during submergence.
ER -