A molecular rheostat of ABA signaling coordinates the trade-off between stem growth and drought adaptation.
7 affiliations
- 1State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, People's Republic of China.
- 2National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, People's Republic of China.
- 3Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, People's Republic of China.
- 4College of Forestry, State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, Shandong Agricultural University, Tai'an 271018, Shandong, People's Republic of China.
- 5State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, People's Republic of China. [email protected].
- 6National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, People's Republic of China. [email protected].
- 7Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing, 100083, People's Republic of China. [email protected].
Abstract
Background
Plants balance vegetative growth and stress responses through antagonistic phytohormone crosstalk, notably between abscisic acid (ABA) and cytokinin. However, the genetic architecture and molecular mechanisms driving this adaptive trade-off, particularly in perennial trees, remain elusive.Results
Integrating genome-environment and genome-wide association studies across 302 Populus tomentosa accessions, we identify PtoAG1 as a pleiotropic regulator of climate adaptation and stem growth. A naturally occurring frameshift mutation abolishes its repressor function, driving geographical niche differentiation by enhancing growth in humid habitats. Mechanistically, PtoAG1 acts as a molecular rheostat. Under drought, ABA-activated PtoSnRK2.2 phosphorylates PtoMYB84 to transactivate PtoAG1. PtoAG1 then represses the cytokinin-signaling regulator PtoRR12, consequently releasing its inhibition of PtoSnRK2.2. This positive feedback further suppresses vegetative growth under stress while amplifying ABA responses via PtoAREB3. Concurrently, PtoAG1 directly represses PtoAREB3 as a transcriptional brake to maintain signaling homeostasis. Evolutionary analyses reveal that PtoMYB84 and PtoAG1 constitute a tightly linked cis-regulatory module conserved across eudicots. Functional analysis on AG1 orthologs in poplar, Arabidopsis, rice, and tomato demonstrates conserved cross-species utility: loss-of-function increases vegetative biomass but overexpression significantly boosts drought resilience.Conclusions
Our study identifies a hierarchical crosstalk mechanism bridging ABA and cytokinin signaling to optimize environmental fitness. The evolutionarily conserved MYB84-AG1 cis-regulatory module establishes a versatile, translatable genetic target for precision breeding of climate-resilient and high-yielding crops.
Related
- OPA1-dependent mitochondrial remodeling coordinates TCR signaling and metabolic adaptation during iNKT cell differentiation
- Integrated Molecular and Physiological Mechanisms Underlying Rice Adaptation to Heat, Salinity, and Drought Stress.
- Multi-Year Characterisation of Drought Adaptation and Grain Quality in Synthetic Hexaploid Wheat Genotypes
- Tylosema esculentum (Marama Bean) as a Climate-Resilient Opportunity Crop: A Review of Nutritional, Medicinal, andGenomics Insights and Drought Adaptation
- Dishevelled 2 coordinates aortic Notch signaling through primitive myeloid and hemogenic endothelial cells during hematopoietic stem cell specification
BibTeX
@article{lv2026molecular,
title = {{A molecular rheostat of ABA signaling coordinates the trade-off between stem growth and drought adaptation.}},
author = {Chenfei Lv and Yuling He and Donghai Zhang and Mengjiao Zhang and Mingjia Yuan and Leishi Zhong and Chongde Tian and Jiaxuan Zhou and Rui Huang and Zhuoying Jin and Peng Li and Wenjie Lu and Liang Xiao and Jinlong Li and Mingyang Quan and Zhonghai Li and Rui Zhao and Liang Du and Li-Jun Liu and Deqiang Zhang and Qingzhang Du},
journal = {Genome biology},
year = {2026},
month = aug,
doi = {10.1186/s13059-026-04228-2},
url = {https://europepmc.org/article/MED/42963550},
note = {CC BY},
}
RIS
TY - JOUR
TI - A molecular rheostat of ABA signaling coordinates the trade-off between stem growth and drought adaptation.
AU - Chenfei Lv
AU - Yuling He
AU - Donghai Zhang
AU - Mengjiao Zhang
AU - Mingjia Yuan
AU - Leishi Zhong
AU - Chongde Tian
AU - Jiaxuan Zhou
AU - Rui Huang
AU - Zhuoying Jin
AU - Peng Li
AU - Wenjie Lu
AU - Liang Xiao
AU - Jinlong Li
AU - Mingyang Quan
AU - Zhonghai Li
AU - Rui Zhao
AU - Liang Du
AU - Li-Jun Liu
AU - Deqiang Zhang
AU - Qingzhang Du
PY - 2026
DA - 2026/08/04
JO - Genome biology
DO - 10.1186/s13059-026-04228-2
UR - https://europepmc.org/article/MED/42963550
AB - Background Plants balance vegetative growth and stress responses through antagonistic phytohormone crosstalk, notably between abscisic acid (ABA) and cytokinin. However, the genetic architecture and molecular mechanisms driving this adaptive trade-off, particularly in perennial trees, remain elusive.Results Integrating genome-environment and genome-wide association studies across 302 Populus tomentosa accessions, we identify PtoAG1 as a pleiotropic regulator of climate adaptation and stem growth. A naturally occurring frameshift mutation abolishes its repressor function, driving geographical niche differentiation by enhancing growth in humid habitats. Mechanistically, PtoAG1 acts as a molecular rheostat. Under drought, ABA-activated PtoSnRK2.2 phosphorylates PtoMYB84 to transactivate PtoAG1. PtoAG1 then represses the cytokinin-signaling regulator PtoRR12, consequently releasing its inhibition of PtoSnRK2.2. This positive feedback further suppresses vegetative growth under stress while amplifying ABA responses via PtoAREB3. Concurrently, PtoAG1 directly represses PtoAREB3 as a transcriptional brake to maintain signaling homeostasis. Evolutionary analyses reveal that PtoMYB84 and PtoAG1 constitute a tightly linked cis-regulatory module conserved across eudicots. Functional analysis on AG1 orthologs in poplar, Arabidopsis, rice, and tomato demonstrates conserved cross-species utility: loss-of-function increases vegetative biomass but overexpression significantly boosts drought resilience.Conclusions Our study identifies a hierarchical crosstalk mechanism bridging ABA and cytokinin signaling to optimize environmental fitness. The evolutionarily conserved MYB84-AG1 cis-regulatory module establishes a versatile, translatable genetic target for precision breeding of climate-resilient and high-yielding crops.
SN - 1474-7596
SN - 1474-760X
ER -