Proteogenomics analysis of seed dormancy identifies genotype- and phenotype-associated proteomic signatures of pre-harvest sprouting resistance in dormant and non-dormant hybrid genotypes of wheat.
Bykova NV, Jordan M, Radovanovic N, Rampitsch M, Hu-Skrzenta J (2017) Proteogenomics analysis of seed dormancy identifies genotype- and phenotype-associated proteomic signatures of pre-harvest sprouting resistance in dormant and non-dormant hybrid genotypes of wheat. 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. Poster number 246-DV.
Control of pre-harvest sprouting (PHS) resistance in wheat is complex, genetic factors responsible for it are dispersed on almost every wheat chromosome and interactions occur between QTLs and/or among environments. Elucidation of molecular mechanisms controlling seed dormancy, after-ripening and environmental regulation reveal sources of genetic variation. In this study, we used proteogenomics approach to identify seed tissue-specific proteomic signatures of PHS resistance. Dormancy genotype- and phenotype-associated alterations in aleurone and embryo proteomes were analyzed using a hard white spring wheat (Triticum aestivum L.) hybrid doubled haploid lines with marginal dormancy phenotypes, iTRAQ-based proteomics integrated with customized EST database, high-resolution nanoLC-MS/MS and Scaffold Q+ quantitative analysis, Mercator annotation pipeline, MapMan pathway mapping, and association with QTL regions. Altogether 6810 proteins in 4116 clusters were identified with high confidence, of which 62 and 115 unique proteins showed significant differential expression in dormant phenotypes, and 368 and 1041 unique proteins were dormancy genotype-specific in embryo and aleurone, respectively. In dormant embryos, significant phenotype-specific changes were found for proteins involved in redox controlling system, signaling associated with flowering, development and growth repression, hormone signaling, cell cycle control and epigenetic regulation of gene expression, cell wall metabolism, vesicle transport, and ubiquitin 26S proteasome pathway. Phenotype-specific changes in aleurone involved proteins responsible for defenses against pathogens, energy metabolism, protein turnover, RNA processing, nucleotide synthesis, vitamin metabolism, G-proteins, ABA and ethylene metabolism. Corresponding genes on chromosome arms where QTL for PHS tolerance had been previously identified were further analyzed to compare their location in the QTL region.