Wheat E3 ligase TaPRP19 is involved in drought stress tolerance in transgenic Arabidopsis

TaPRP19, a wheat U-box E3 ligase gene, was isolated and characterized for its role in drought stress tolerance. The gene encodes a 531 amino acid protein with a U-box domain at the N-terminal and a WD40 domain at the C-terminal. Subcellular localization studies using TaPRP19-GFP fusion in Nicotiana benthamiana confirmed predominant nucleus localization. In vitro ubiquitination assays demonstrated that TaPRP19 possesses E3 ligase activity. RT-qPCR analysis revealed higher expression of TaPRP19 in wheat leaves, which increased under PEG, mannitol, and ABA treatments. Transgenic Arabidopsis lines overexpressing TaPRP19 exhibited improved seed germination rates and root elongation under mannitol and ABA stress, as well as enhanced survival rates under drought conditions compared to wild-type (WT) plants. Additionally, these transgenic lines showed upregulated expression of antioxidant-related and drought-marker genes, reduced ROS accumulation, and increased activities of antioxidant enzymes, suggesting enhanced oxidative stress mitigation. These findings highlight TaPRP19 as a potential target for developing drought-tolerant crops, providing insights into its functional mechanisms and paving the way for future genetic engineering applications in wheat and other crops.