Antagonistic SnRK2 and PID kinases' action on auxin transport–mediated root gravitropism
Plants have evolved sophisticated mechanisms to adapt to environmental changes, with root gravitropism playing a pivotal role in nutrient and water acquisition. Our study reveals that SnRK2 kinases (SnRK2.2 and SnRK2.3) are critical regulators of root gravitropism through their direct phosphorylation of the auxin transporter PIN2 at S259. We demonstrate that SnRK2s-mediated phosphorylation modulates both the polar localization and transport activity of PIN2. Importantly, SnRK2s function antagonistically to the AGCVIII kinase PID, which phosphorylates PIN2 at a distinct site (S258), establishing a regulatory balance essential for adaptive root growth. Structural modeling and phosphorylation assays further suggest that SnRK2s-mediated phosphorylation at S259 sterically hinders access of PID to S258, providing a mechanistic basis for their antagonistic relationship. These findings uncover a novel regulatory mechanism, by which plants fine-tune root developmental programs to adapt to environmental stimuli, highlighting the evolutionary significance of multilayered kinase-mediated regulation in plant adaptation.
Authors
- Jing Zhang (ORCID: https://orcid.org/0000-0002-1759-1041)
- Gao Yu (ORCID: https://orcid.org/0000-0001-7722-2136)
- Xinyan Qin (ORCID: https://orcid.org/0000-0001-5560-6569)
- Jiřı́ Friml (ORCID: https://orcid.org/0000-0002-8302-7596)
- Yan Guo (ORCID: https://orcid.org/0000-0002-6955-8008)
- Jigang Li (ORCID: https://orcid.org/0000-0002-4395-2656)
- Wen Song (ORCID: https://orcid.org/0000-0002-9498-2409)
- Sheng Fang (ORCID: https://orcid.org/0000-0002-9516-4256)
- Shujuan Zhang (ORCID: https://orcid.org/0009-0003-1540-3064)
- Qun Zhang (ORCID: https://orcid.org/0000-0002-4477-1478)
- Yang Li (ORCID: https://orcid.org/0000-0002-0736-251X)
- Yaping Wang (ORCID: https://orcid.org/0000-0002-2740-1731)
- Jing Zhang (ORCID: https://orcid.org/0000-0002-3808-433X)
- Zhizhong Gong (ORCID: https://orcid.org/0000-0001-6551-6014)
- Zhaoheng Zhang
Institutions
- Nanjing Agricultural University (CN)
- Institute of Science and Technology Austria (AT)
- Institute of Vegetables and Flowers (CN)
- Chinese Academy of Agricultural Sciences (CN)
- Naval Aerospace Medical Institute (US)
- Hebei University (CN)
- China Agricultural University (CN)
Publication Details
- Journal
- Proceedings of the National Academy of Sciences
- Published
- 2025-09-23
- DOI
- https://doi.org/10.1073/pnas.2512274122
- Citations
- 3
- Primary Topic
- Plant nutrient uptake and metabolism
- Type
- article
- Field-Weighted Citation Impact
- 5.25
Funders
- China Agricultural University
- Austrian Science Fund
- China Postdoctoral Science Foundation
- National Science and Technology Major Project
- Chinese Universities Scientific Fund