Heterologous expression of Halostachys caspica pathogenesis-related protein 10 increases salt and drought resistance in transgenic Arabidopsis thaliana.

Pathogenesis-related proteins (PR), whose expressions are induced by biotic and abiotic stress, play important roles in plant defense. Previous research identified the salt-induced HcPR10 gene in the halophyte Halostachys caspica as a regulator of plant growth and development through interactions with cytokinin. However, the mechanisms by which HcPR10 mediates resistance to abiotic stress remain poorly understood. In this study, we found that the heterologous expression of HcPR10 significantly enhanced salt and drought tolerance in Arabidopsis, likely by increasing the activity of antioxidant enzyme systems, allowing for effective scavenging of reactive oxygen species (ROS) and thus protecting plant cells from oxidative damage. Additionally, the overexpression of HcPR10 also activated the expression of stress-related genes in Arabidopsis. Furthermore, using yeast two-hybrid technology, five proteins (HcLTPG6, HcGPX6, HcUGT73B3, HcLHCB2.2, and HcMSA1) were identified as potential interacting partners for HcPR10, which could positively regulate the salt stress response mediated by HcPR10. Our findings lay the foundation for a better understanding of the molecular mechanisms of HcPR10 in response to abiotic stress and reveal additional candidate genes for improving crop salt tolerance through genetic engineering.