Abstract:Sweetpotato [Ipomoea batatas (L.) Lam.] is highly susceptible to a variety of biotic and abiotic stresses during its growth and development. These stresses can severely disrupt its growth and development, which in turn causes a significant decline in quality and yield. Therefore, identifying stress-resistance-related genes in sweetpotato, exploring their functions and mechanisms, and breeding new varieties with enhanced stress resistance are crucial for improving salt and drought tolerance and ensuring the sustainable development of the sweetpotato. SAUR (small auxin up RNA) genes are key components of the auxin signaling pathway and play essential roles in regulating plant growth and development as well as in responding to abiotic stresses. To investigate the function and mechanism of the IbSAUR76 gene in sweetpotato, we cloned this gene and constructed an IbSAUR76-GFP fusion expression vector. Our results showed that the IbSAUR76 protein is localized in the nucleus. To gain deeper insights into the role of the IbSAUR76 gene in the stress response of sweetpotato, we then cloned its promoter sequence. The prediction of cis-acting elements revealed that the IbSAUR76 promoter contains multiple stress and hormone response elements. Under drought and salt treatments, the expression level of IbSAUR76 was significantly upregulated, indicating that this gene plays a role in the stress response of sweetpotato. Moreover, a bait vector for IbSAUR76 was constructed and used to screen the sweetpotato cDNA yeast library, identifying 27 candidate proteins that interact with IbSAUR76. Among these, two interaction proteins related to abiotic stress, IbERF2 and IbHOS15, were verified using yeast two-hybrid back-transformation. In summary, this study not only enriches our understanding of the IbSAUR76 gene in sweetpotato but also provides a solid theoretical foundation for further in-depth analysis of its function. The identification and characterization of IbSAUR76 and its interacting proteins are significant steps toward developing more stress-resistant sweetpotato varieties. Among these, two interaction proteins related to abiotic stress, IbERF2 and IbHOS15, were verified by yeast two-hybrid (Y2H). In summary, this study not only enriches our knowledge of the IbSAUR76 gene in sweetpotato but also provides a theoretical basis for further in-depth analysis of its function.