The Co-Suppression of Translation Elongation Factor-1α Impairs Plant Growth and Reduces Heat Tolerance in Tomato

The Translation Elongation Factor 1α (EF1α) protein is essential for the process of protein elongation in all eukaryotic organisms. In tomato (Solanum lycopersicum L.) the soluble fraction of SlEF1α protein rapidly decreased when subjected to temperatures exceeding 40°C for 2 h in vitro, whereas a significant portion of SlEF1α remained in the soluble form in vivo even after being exposed to 48°C treatment for 9 h. These findings indicate that protective mechanisms exist to maintain SlEF1α in a soluble state under heat stress conditions. Given the well-established role of EF1α in protein translation, heat-induced reduction of soluble SlEF1α is likely to impair protein synthesis. Notably, overexpression of SlEF1α enhanced the heat tolerance of plants, whereas the co-suppression of SlEF1α resulted in a dwarf phenotype, leaf curling, and increased sensitivity to heat stress. Collectively, these results reveal that SlEF1α is a thermosensitive protein that plays a crucial role in the heat response and growth of plants.