The global escalation of soil salinization has led to increased water erosion, adversely impacting plant growth and development. Heat shock proteins (HSPs) are highly conserved proteins found across a wide range of organisms. When biological organisms are stimulated by the external environment, they will express themselves in large quantities. HSPs play a pivotal role in mediating plant responses to abiotic stress. This study identified 22 members of the PcHsp20 gene family with complete open reading frames (ORFs) through transcriptomic analysis conducted under Pugionium cornutum salt stress, and evaluated their expression levels. Notably, PcHsp18.1 was significantly upregulated in the leaves of Pugionium cornutum (L.) Gaertn. Based on this, we cloned the PcHsp18.1 gene and determined through subcellular localization that PcHsp18.1 is localized in both the cytoplasm and nuclear membrane. Subsequently, we transformed the PcHsp18.1 gene into Arabidopsis thaliana to investigate its involvement in the response to salt stress. The results indicated that the overexpressing (OE) plants exhibited improved growth conditions, higher seed germination rates, increased root lengths, a greater number of lateral roots, reduced relative conductivity, and elevated relative chlorophyll content compared to the wild-type (WT) plants. These findings suggesting that the transgenic line possesses enhanced salt tolerance. Moreover, the concentrations of malondialdehyde (MDA) and relative conductivity in the overexpressing (OE) plants were significantly lower than those observed in the wild-type (WT) plants, suggesting a reduced extent of damage to their cell membranes. In comparison to the wild type (WT), the transgenic line (OE) exhibited elevated activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), along with increased proline content, suggesting that the transgenic plants possess enhanced resistance to abiotic stress and a greater capacity for scavenging reactive oxygen species (ROS). Meanwhile, salt treatment resulted in the significant expression of stress-related genes in the transgenic plants. These results indicate that PcHsp18.1 positively regulates salt stress in Arabidopsis.

Soil salinization-alkalization severely affects plant growth and crop yield worldwide, especially in the Songnen Plain of Northeast China. Saline-alkaline stress increases the pH around the plant roots, thereby limiting the absorption and transportation of nutrients and ions, such as iron (Fe). Fe is an essential micronutrient that plays important roles in many metabolic processes during plant growth and development, and it is acquired by the root cells via iron-regulated transporter1 (IRT1). However, the function of Oryza sativa IRT1 ( OsIRT1 ) under soda saline-alkaline stress remains unknown. Therefore, in this study, we generated OsIRT1 mutant lines and OsIRT1-- overexpressing lines in the background of the O. sativa Songjing2 cultivar to investigate the roles of OsIRT1 under soda saline-alkaline stress. The OsIRT1- overexpressing lines exhibited higher tolerance to saline-alkaline stress compared to the mutant lines during germination and seedling stages. Moreover, the expression of some saline-alkaline stress-related genes and Fe uptake and transport-related genes were altered. Furthermore, Fe and Zn contents were upregulated in the OsIRT1-overexpressing lines under saline-alkaline stress. Further analysis revealed that Fe and Zn supplementation increased the tolerance of O. sativa seedlings to saline-alkaline stress. Altogether, our results indicate that OsIRT1 plays a significant role in O. sativa by repairing the saline-alkaline stress-induced damage. Our findings provide novel insights into the role of OsIRT1 in O. sativa under soda saline-alkaline stress and suggest that OsIRT1 can serve as a potential target gene for the development of saline- -alkaline stress-tolerant O. sativa plants.