Terpene synthase TgHPTPS2 from Torreya grandis modulates terpenoid profiles to balance ROS and confer drought...

Drought stress is a significant environmental constraint that hampers plant growth and productivity, largely due to oxidative damage caused by excessive reactive oxygen species (ROS) accumulation. Terpenoids, a class of essential secondary metabolites, are essential in alleviating oxidative stress by regulating ROS homeostasis. However, the molecular mechanisms by which terpenoid metabolism enhances drought tolerance remain unclear. Herein, we characterized TgHPTPS2, a hypothetical terpene synthase gene from Torreya grandis, which is transcriptionally upregulated in response to drought stress. The ectopic expression of TgHPTPS2 in Arabidopsis thaliana resulted in enhanced drought tolerance, characterized by improved ROS scavenging capacity and greater root system development. Targeted metabolomics revealed that TgHPTPS2 alters terpenoid metabolism, resulting in reduced ROS levels in transgenic lines. Furthermore, dual-luciferase reporter and yeast one-hybrid assays revealed that TgMYB12, a drought-inducible transcription factor, directly binds to the TgHPTPS2 promoter and inhibits its expression. These findings designate TgHPTPS2 as a crucial regulatory component in terpenoid-mediated drought tolerance and offer a new perspective on the transcriptional regulation of terpenoid biosynthesis in response to abiotic stress.