Proteomic analysis of physiochemical deterioration in the embryo of hard and soft wheat

The physiochemical deterioration of wheat grains occurs naturally during long-term storage and poses challenges to the preservation of germplasm resources, seed quality, and nutritional quality. Soft wheat tolerates storage better than hard wheat, but the underlying molecular mechanism remains unclear. This study analyzed the proteomic changes in hard (Yangmai 16) and soft wheat (Yangmai 15) seeds after controlled deterioration treatment (CDT). The results showed that under the same storage conditions, Yangmai 15 had better embryo vigor than Yangmai 16, which may be attributed to the high expression of oxidases and oxidants in the ROS-scavenging system of Yangmai 15 embryos. In addition, the H₂O₂ content and oxidative damage to the membrane were also relatively reduced in Yangmai 15 embryos compared with those in Yangmai 16 embryos. Label-free quantitative proteomics of the embryo tissues of treated and untreated wheat showed that multiple upregulated heat shock proteins in Yangmai 15 embryos and the downregulation of most peroxidase genes in Yangmai 16 embryos were the main reasons for the difference in storage tolerance between hard and soft wheat. However, in deteriorated Yangmai 15 embryos, the upregulated pyridoxine kinase (PLK) and Dehydrin2 (DHN2) can defend against artificial aging stress, which may explain why Yangmai 15 has high storage tolerance during CDT.