Abstract
Soil salinization significantly limits plant growth and agricultural productivity, with MYB transcription factors playing crucial roles in mediating plant responses to salt stress. In this study, a novel R2R3-MYB transcription factor gene, SlMYB306-like, was isolated from tomato. Phylogenetic comparison indicated that SlMYB306-like shared the highest sequence homology with potato StMYB306-like. Subcellular localization assays demonstrated nuclear localization of SlMYB306-like protein, while yeast transactivation assays confirmed its function as a transcriptional activator. Expression profiling showed that SlMYB306-like was inducible by NaCl and abscisic acid (ABA) treatments. In addition, functional characterization via the overexpression of SlMYB306-like in Arabidopsis thaliana revealed enhanced salt tolerance, evidenced by an increased maximum quantum efficiency of photosystem II (Fv/Fm) and proline levels alongside decreased accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) content under salt stress conditions. Furthermore, the overexpression of SlMYB306-like upregulated the expression of several stress-responsive genes, including AtSOD1, AtCAT1, AtEGY3, AtP5CS2, and AtRD29A. Collectively, these findings suggest that SlMYB306-like enhances salt tolerance by modulating ROS scavenging, osmotic adjustment, and ABA signaling pathways, thereby representing a promising candidate gene for the development of salt-tolerant crops.