BIN2 phosphorylation of GRF5 suppresses low nitrate root foraging by inhibiting transcriptional activity and UBP12/13-mediated deubiquitination
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ABSTRACT: Root developmental plasticity enables plants to adapt to nutrient-deficient conditions. Under low nitrate conditions, enhanced exploratory root growth—characterized by increased primary and lateral root elongation—facilitates nutrient foraging. Although nitrate-hormone crosstalk regulates this process, the underlying molecular mechanisms remain poorly understood. Here, we identify a BIN2-GRF5-UBP12/13 module governing root foraging responses to low nitrate in Arabidopsis. We demonstrate that BIN2 phosphorylates GRF5 at Ser-205, reducing its stability and transcriptional activity. Integrative DAP-seq and transcriptome analyses revealed that GRF5 directly regulates key nitrate-responsive genes, including the dual-affinity transporter 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 stabilize GRF5 to promote lateral root elongation under low nitrate conditions. Our work delineates a phosphorylation-dependent regulatory circuit that fine-tunes root foraging adaptation, advancing the mechanistic understanding of nitrate sensing in plants.
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE316090 | GEO | 2026/03/17
REPOSITORIES: GEO
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