Abstract
Soybean (Glycine max) is a vital oilseed and economic crop in China, often constrained by drought, salinity, and biotic stresses. In this study, we identified a soybean bZIP transcription factor, GmbZIP59, whose expression is upregulated by salt, drought, ethylene (ETH), methyl jasmonate (MeJA), and abscisic acid (ABA). Overexpression of GmbZIP59 in Arabidopsis (OE-13 and OE-20, two independent Arabidopsis transgenic lines) exhibited enhanced resistance to Sclerotinia sclerotiorum (S. sclerotiorum), improved tolerance to salt stress, and increased sensitivity to phytohormones. Overexpression of GmbZIP59 in rice (OE-1 and OE-2, two independent rice transgenic lines) improved tolerance to salt and drought stresses. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that elevated expression of stress-related genes occurred in transgenic lines under adverse conditions. Furthermore, chromatin immunoprecipitation-qPCR (ChIP-qPCR) assays confirmed that GmbZIP59 directly binds to the promoters of ETH, MeJA, and ABA, responsive genes associated with stress responses. These findings demonstrate that GmbZIP59 acts as a positive regulator of biotic and abiotic stress tolerance in soybean.