Trans-zeatin modulates shade stress adaptation in soybean through transcription associated metabolic network

This study explores the molecular mechanisms by which trans-zeatin (tZ), a cytokinin, influences shade stress responses in shade-sensitive and shade-tolerant recombinant inbred lines (RILs) 160 and 165 of soybean (Glycine max) under varied light conditions. Using an integrative multi-omics approach combining metabolomics and transcriptomics, we elucidate the regulatory networks underlying soybean adaptation to shade stress. Using an integrative multi-omics approach that combines metabolomics and transcriptomics, we dissect the complex regulatory networks that enable soybean plants to adapt to shade stress. Our results demonstrate that tZ significantly affects growth, biomass accumulation, photosynthetic efficiency, and yield in soybean plants. Metabolomic analysis revealed that shade stress impacts key metabolic pathways, including phenylpropanoids, flavonoids, flavone and flavonol, anthocyanin, and brassinosteroid biosynthesis, with tZ treatment enhances the adaptive responses of soybean plants. Transcriptomic data further identified differential gene expression in these pathways, alongside those related to hormone-mediated signaling pathway, cell wall biogenesis, and defence response pathways underlining the molecular adjustments to tZ and shade stress. Importantly, the integration of metabolomics and transcriptomics data revealed key KEGG pathways and genes regulated by tZ treatment in RIL 160 under shade stress, including significant alterations in phenylpropanoids, flavonoids, hormone-mediated signaling pathway, cell wall biogenesis and defence response, anthocyanin biosynthesis, and fatty acid degradation pathways as well key responsive transcription factors. This study provides insights into the role of tZ in mediating soybean responses to shade stress at the molecular level, offering insights into improving soybean resilience to low light conditions and informing future agricultural practices for optimizing crop yield.