Regulation of LOV1 in Ulva prolifera thermotolerance: A preliminary study

Temperature is a critical environmental factor for the proliferation of Ulva prolifera, the dominant species of green tides. Physiological studies have reported that U. prolifera grows optimally at 20-28 °C and is inhibited at higher temperatures. However, the molecular basis of its thermal adaptation remains unclear. This study bridges this gap by identifying the LOV1 gene, which exhibits significant upregulation under elevated temperatures, suggesting its involvement in the heat stress response. The function of LOV1 was characterized by heterologous expression in yeast and transgenic Arabidopsis. Overexpression of LOV1 increased thermotolerance by improving growth and antioxidant traits of transgenic lines. As oxidative stress in heat damage is important, we investigated the molecular mechanisms, and found that there was an interaction between LOV1 and Mn-SOD by yeast two-hybrid and GST pull down experiments. This interaction indicates that LOV1 may improve thermotolerance by strengthening the antioxidant system in U. prolifera. These findings reveal a previously unrecognized role of LOV1 in the heat stress response of U. prolifera and provide new molecular insights into its adaptation to summer temperatures that coincide with green tide outbreaks.