Salt stress response pathway and regulatory mechanism of the Malus domestica G protein-coupled receptor MdGPCR

China accounts for about half of the world's apple area and production, and is a pillar industry that promotes farmers' income growth and rural revitalization. In recent years, with the dramatic change of the global climate, most apple (Malus domestica) producing areas in China have suffered salt damage. Soil salinization, especially secondary salinization, is common in apple producing areas in the North China Plain around the Bohai Sea. These phenomena indicate that the ability of apple industry to prevent and resist soil salinization still needs to be improved. In this article, we identified a novel salt sensitive gene MdGPCR in apple. We conducted salt stress experiments on apple callus and leaves using MdGPCR. The results showed that after salt stress, overexpression of MdGPCR in transgenic apple would accumulate a large amount of reactive oxygen species, leading to an imbalance of redox levels in their bodies. At the same time, MdGPCR interacts with MdSOS3 and promotes its degradation, further reducing its salt stress resistance.