Abstract

Salinity stress severely limits rice productivity. Understanding how crops sustain growth during prolonged salt stress exposure is therefore of critical importance. Here, we demonstrate that a brassinosteroid (BR)-jasmonic acid (JA) signaling network integrates nitrate signals to remodel root cell walls and promote salt recovery in rice ( Oryza sativa ). The GSK3-like kinase OsGSK1 interacts with and phosphorylates the transcription factor BRASSINAZOLE-RESISTANT3 (OsBZR3), which negatively regulates root growth recovery and seedling survival under prolonged salt stress. OsBZR3 fine-tunes root cell wall thickening and compositional remodeling, as well as the nitrate response in rice under salt stress. Notably, high nitrate supply represses the salt stress-induced phosphorylation of OsBZR3 by OsGSK1. OsBZR3 acts upstream of the JA signaling repressor Jasmonate ZIM-domain (JAZ) 4 (OsJAZ4) by directly binding to its promoter region. The OsGSK1-OsBZR3 module regulates OsJAZ4 activity to orchestrate the expression of downstream cell wall remodeling genes under salt stress. In short, our findings establish the OsGSK1-OsBZR3-OsJAZ4 module as a potential hub integrating nitrate and hormonal signals under prolonged salt stress, identifying novel key genetic targets for breeding salt-resilient crops and advancing sustainable green agricultural practices.