Redox regulation of after-ripening induced wheat seed dormancy release revealed through tissue-specific proteomics and antioxidant capacity profiling.
Hu-Skrzenta J, Radovanovic N, Rampitsch M, Igamberdiev AU, Bykova NV (2017) Redox regulation of after-ripening induced wheat seed dormancy release revealed through tissue-specific proteomics and antioxidant capacity profiling. In: Plants from Sea to Sky. A joint meeting of the CSPB and the Canadian Society for Horticultural Science, Vancouver, British Colombia, Canada, July 4-7, 2017. Oral presentation, student
Alleviation of wheat seed dormancy during dry after-ripening involves reactive oxygen species (ROS) production, which triggers redox regulation of protein thiols and changes in functional proteome. Seed dormancy is closely associated with pre-harvest sprouting (PHS) tolerance. Tissue-specific redox proteomics studies contribute to understanding of molecular mechanisms controlling dormancy and after-ripening and further reveal candidate genes likely to contribute to PHS resistance traits in wheat. We analyzed dormancy genotype-associated and after-ripening induced alterations in embryo and aleurone redox proteomes using hard white spring wheat hybrid doubled haploid lines with marginal dormancy phenotypes, fluorescent labeling of redox active cysteines, high resolution 2-DE, LC-MS/MS analysis in conjunction with wheat EST database mining, quantitative spectral counting analysis, bioinformatics interpretation and visualization through MapMan. Redox proteomic analysis resulted in 689 high confidence protein identifications with at least two-fold change in protein expression and/or redox level between dormant and after-ripened seeds, from which 115 and 204 proteins showed significant disulfide/thiol ratio changes in dormant embryo and aleurone, respectively. Diagnostic proteins in dormant embryo were found to be involved in ascorbate regeneration, membrane trafficking, DNA methylation-dependent gene silencing, ABA and stress-responsive regulation of reproductive development. The level of total glutathione was significantly higher in dormant than in non-dormant and after-ripened embryos, whereas the level of total ascorbate increased 2-3 fold upon after-ripening. Therefore, glutathione and ascorbate antioxidants have different roles in redox control of seed dormancy and germination potential.