SQUAMOSA-Promoter Binding Protein Like 10/14 (OsSPL10/14) Regulate Salt Tolerance by Modulating Reactive Oxygen Species Homeostasis in Rice (Oryza Sativa L.).

Soil salinization seriously impacts the growth and development, yield, and grain quality of crops. Elucidating the molecular underlying of salt tolerance is crucial for advancing stress-resistant molecular breeding research in crops. Here, we identified a salt stress-responsive gene, SQUAMOSA-promoter binding protein like 10 (OsSPL10), and characterized its molecular function in conferring salt tolerance to rice. Firstly, we generated and characterized three distinct types of spl10 mutants using CRISPR/Cas9 mutagenesis. In spl10 mutant, the leaf withered rate was lower than that in wild type (WT), the plant height and fresh weight per plant of spl10 were higher than WT under salt stress, indicating that spl10 exhibits tolerance to salt stress. Based on biochemical and physiological assays, the OsSPL10/14 complex was identified as a key regulator of salt stress response in rice by modulating the homeostasis of reactive oxygen species (ROS). Besides, the RNA-Seq assay confirmed that OsSPL10 may be involved in plant hormone signal transduction and phenylpropanoid biosynthesis pathways under salt stress, providing valuable insights for exploring the downstream target genes of OsSPL10. These findings offer novel insights into the molecular mechanisms underlying salt tolerance mediated by the SPL transcription factor in plants.