The Gene <i>SiPrx</i> from <i>Saussurea involucrata</i> Enhances the Stress Resistance of <i>Silphium perfoliatum</i> L.

Peroxiredoxin (Prx) plays a role in maintaining the balance of intracellular reactive oxygen species. The peroxidase <i>SiPrx</i> gene from the Tianshan Snow Lotus (<i>Saussurea involucrata</i>) has been proved to significantly enhance the stress resistance of plants. In this study, the <i>SiPrx</i> gene was expressed heterogeneously in high-quality herbage <i>Silphium perfoliatum</i> L. (SP). After treatment with NaCl, the transgenic SP only exhibited partial leaf wilting, whereas the wild-type (WT) plants were on the brink of death. Simultaneously, physiological and biochemical assays indicated that under high-salt conditions, the content of malondialdehyde in the transgenic plants was significantly lower than that in the WT plants, while the activity of antioxidant enzymes was significantly higher than that in the WT plants. The expression of the <i>SiPrx</i> gene has been shown to significantly enhance the salt stress resistance of transgenic SP. Furthermore, after treatment at −10 °C for 48 h, the leaves of transgenic plants were able to maintain a certain morphological structure, whereas the WT plants were completely wilted. Physiological and biochemical index measurements indicated that all indicators in the transgenic plants were significantly better than those in the WT plants. Based on these findings, this study plans to overexpress the <i>SiPrx</i> gene extracted from <i>Saussurea involucrata</i> in Comfrey using the Agrobacterium-mediated method and then study its effects on the stress resistance of transgenic SP. The research results indicate that the <i>SiPrx</i> gene shows significant application potential in enhancing the cold resistance and salt tolerance of SP. This study provides a certain research basis and scientific evidence for the mining of stress resistance genes in <i>Saussurea involucrata</i> and the cultivation of new varieties of SP.