Integrated Transcriptomic and Metabolomic Analysis Reveals the Role of <i>SlOSCA8</i> in Enhancing Cold Tolerance in Tomato ( <i>Solanum lycopersicum</i> )

In recent years, increasing frequency of extreme weather events has caused serious damage to the growth and development of tomatoes. SlOSCA8, a hyperosmolality-gated calcium channel protein, plays a crucial role in regulating plant stress responses. Previous studies have shown that SlOSCA8 responds to cold stress, but its regulatory mechanism remains unclear. In this study, we demonstrated that overexpression of <i>SlOSCA8</i> in tomato plants enhances cold tolerance, whereas <i>slosca8</i> knockout mutants exhibited increased sensitivity to low temperatures at 4 °C. Further investigation revealed that SlOSCA8 enhances cold tolerance by promoting Ca²⁺ influx. Integrated transcriptomic and metabolomic analyses revealed significant alterations in phenylalanine and phenylpropanoid biosynthesis pathways in <i>SlOSCA8</i>-overexpressing plants, leading to increased flavonoid accumulation and, consequently, improved cold tolerance. These findings underscore the pivotal role of SlOSCA8 in regulating tomato responses to cold stress and provide valuable insights into its regulatory mechanism, offering a theoretical foundation for the breeding cold-tolerant tomato varieties.