Sulfuric Acid and Gibberellic Acid (GA3) Treatment Combined with Exposure to Cold Temperature Modulates Seed Proteins during Breaking of Dormancy to Germination in Tilia miqueliana.

Tilia miqueliana produces woody seeds that exhibit deep dormancy. In this study, we used cell biology methods, including Paraffin section determination and Coomassie brilliant blue staining, as well as proteomics-based methods, including two-dimensional electrophoresis with matrix-assisted laser desorption/ionisation tandem time-of-flight mass spectrometry (2DE-MALDI-TOF/TOF), to examine the effects of H2SO4-GA3 and cold stratification (3 °C) treatment on proteins during dormancy release and germination in T. miqueliana seeds. The results revealed that during cold stratification, the area and density of proteins in the endosperm cells of H2SO4-GA3-treated seeds were significantly altered. Total protein content was continuously consumed and utilised. Storage proteins (albumin, globulin, prolamin, and glutelin) were degraded to varying degrees. Sixteen differential proteins were identified using mass spectrometry. Kyoto encyclopedia of genes (KEGG) pathway analysis revealed that the glycolysis/gluconeogenesis, secondary metabolite biosynthesis, glyoxylate and dicarboxylate metabolism, amino acid biosynthesis, and metabolic pathways were critical during dormancy release and germination. Gene ontology analysis and KEGG pathway annotation of differential proteins in the co-expression network indicated that the differential proteins are implicated in photosynthesis, glucose metabolism, biosynthesis of plant hormones, and glycolysis/gluconeogenesis. Synergistic interactions among these proteins accelerated dormancy release and germination. Therefore, H2SO4-GA3 cold stratification treatment is the best method for achieving rapid dormancy release and increasing the germination rate of T. miqueliana seeds.