BIN2 phosphorylation of GRF5 suppresses low-nitrate root foraging by inhibiting transcriptional activity and UBP12/13-mediated deubiquitination

  • Cell Rep. 2026 May 26;45(5):117323. doi: 10.1016/j.celrep.2026.117323.
Taotao Li  1 ,  Xiuhong Yao  2 ,  Dongxiao Liu  3 ,  Xinke Kang  4 ,  Ke Fang  5 ,  Mei Zhao  3 ,  Yuqing Zhao  4 ,  Yueli Cai  3 ,  Jingjing Sun  3 ,  Wenhui Tian  3 ,  Luping Gong  3 ,  Zhenjiang Wu  3 ,  Wenxi Wei  3 ,  Mengyuan Li  3 ,  Chunli Liao  3 ,  Lianzhe Wang  3 ,  Honghui Lin  4 ,  Dawei Zhang  6
Affiliations
  • 1. College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan, Henan 467036, China; Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, Laboratory for Ex Situ Conservation and Resource Utilization of Mountane Plants, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
  • 2. Solid-State Fermentation Resource Utilization Key Laboratory of Sichuan Province, Department of Agriculture Forestry and Food Engineering, Yibin University, Yibin, Sichuan 644000, China.
  • 3. College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan, Henan 467036, China.
  • 4. Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, Laboratory for Ex Situ Conservation and Resource Utilization of Mountane Plants, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
  • 5. College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400716, China.
  • 6. Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, Laboratory for Ex Situ Conservation and Resource Utilization of Mountane Plants, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China; Chengdu Botanical Garden, Chengdu, Sichuan 610083, China. Electronic address: [email protected].
PMID: 42054208 DOI: 10.1016/j.celrep.2026.117323
Abstract

Root developmental plasticity enables Plants to adapt to nutrient-deficient conditions. Under low-nitrate (LN) conditions, enhanced exploratory root growth-characterized by increased primary and lateral root (LR) elongation-facilitates nutrient foraging. Although nitrate-hormone crosstalk regulates this process, the underlying molecular mechanisms remain poorly understood. Here, we identify the BIN2-GRF5-UBP12/13 module that governs root foraging responses to LN in Arabidopsis. We demonstrate that BIN2 phosphorylates GRF5 at Ser205, thereby reducing its stability and transcriptional activity. Integrative DAP-seq and transcriptomic analyses reveal that GRF5 directly regulates key nitrate-responsive genes, including the dual-affinity transporter gene NRT1.1 and the high-affinity uptake gene NRT2.1. Furthermore, dephosphorylated GRF5 preferentially interacts with UBIQUITIN-SPECIFIC PROTEASES 12 and 13 (UBP12/13), which stabilizes GRF5 and promotes LR elongation under LN conditions. Our findings delineate a phosphorylation-dependent regulatory circuit that fine-tunes root foraging adaptation, advancing the mechanistic understanding of nitrate sensing in Plants.

Keywords
BIN2; CP: developmental biology; CP: plants; GRF5; UBP12; UBP13; low-nitrate conditions; root developmental plasticity; root foraging.
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