Integrated transcriptomic and proteomic analyses provide insights into potential molecular mechanisms underlying globulin content variation in maize embryos.

BACKGROUND: Globulin in maize kernels is a high-quality protein, which is mainly enriched in the embryo. However, academic research focusing on the molecular mechanism underlying globulin synthesis remains relatively limited to date. Therefore, unveiling the molecular mechanism of globulin synthesis in maize embryos is of great significance for the breeding of high-protein maize varieties. To gain better insights into this mechanism, we integrated transcriptomic and proteomic analysis to identify differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) between two types of materials with distinct globulin contents. RESULTS: Two maize inbred lines were selected for this study, including B73 (low globulin content) and HP434 (high globulin content). Integrated transcriptomic and proteomic analyses revealed that DEGs and DEPs were predominantly enriched in the endoplasmic reticulum (ER) protein processing pathway. Significantly, most of these DEGs and DEPs belonged to the heat shock protein (HSP) family. This indicates that globulin synthesis is closely related to the genes of this family, especially the small molecule heat shock proteins. CONCLUSIONS: The high expression of HSP family genes in HP434 might alleviate the increased ER processing pressure caused by the aggregation of misfolded proteins during the high-abundance synthesis of globulin, thereby contributing to the synthesis of globulin in the ER.