Histone posttranslational modification landscape related to epigenetic regulation of seed dormancy in wheat
Citation
Bykova NV, Rampitsch M, Rampitsch C, Huang M (2018) Histone posttranslational modification landscape related to epigenetic regulation of seed dormancy in wheat. 3rd International Plant Proteomics Organization (INPPO) World Congress. Padova, Italy, September 9-12, 2018. Poster presentation
Plain language summary
Genetic factors responsible for pre-harvest sprouting (PHS) resistance in wheat are dispersed on almost every wheat chromosome and complex interactions occur between QTLs and/or among environments. We applied proteogenomics approach to reveal sources of genetic variation and identify seed tissue-specific proteomic signatures of PHS resistance using hybrid lines with marginal dormancy phenotypes from white and red seeded hard spring wheat DH populations. Dormancy-associated alterations in aleurone and embryo proteomes during early imbibition were analyzed using 8-plex iTRAQ-based proteomics, customized EST database, and association with QTL regions. In white seeded population over 6800 proteins were identified with high confidence, of which 62 and 115 proteins showed significant differential expression in dormant phenotypes, and 368 and 1041 unique proteins were dormancy genotype-specific in embryo and aleurone, respectively. Quantitative proteome analysis in red seeded population resulted in total over 7200 and 3580 proteins identified with high confidence in embryo and aleurone, respectively. Proteomic signatures associated with dormancy phenotype were more evident in white seeded population, whereas genotype-specific and after-ripening induced changes were found in both populations. In dormant embryos, significant phenotype-specific changes were found for proteins involved in redox controlling system, signaling associated with flowering, phytohormones and lipid second messengers, development and growth repression, cell cycle control and epigenetic regulation of gene expression, translational dynamics, cell wall metabolism, vesicle transport, and ubiquitin 26S proteasome pathway. In embryos with non-dormant phenotype energy metabolism showed high capacity for the provision of NADPH reducing equivalents, pyruvate and TCA cycle intermediates for biosynthetic processes. Pathways for energy provision in non-dormant aleurone showed increased flux through the glycolytic pathway, high metabolic network flexibility, and an important role of inorganic pyrophosphate metabolism as an alternative energy donor. Further analysis of the iTRAQ-identified differentially expressed proteins in known QTL regions for PHS tolerance revealed potential candidate genes underlying the QTLs.
Abstract
Genetic factors responsible for pre-harvest sprouting (PHS) resistance in wheat are dispersed on almost every wheat chromosome and complex interactions occur between QTLs and/or among environments. We applied proteogenomics approach to reveal sources of genetic variation and identify seed tissue-specific proteomic signatures of PHS resistance using hybrid lines with marginal dormancy phenotypes from white and red seeded hard spring wheat DH populations. Dormancy-associated alterations in aleurone and embryo proteomes during early imbibition were analyzed using 8-plex iTRAQ-based proteomics, customized EST database, and association with QTL regions. In white seeded population over 6800 proteins were identified with high confidence, of which 62 and 115 proteins showed significant differential expression in dormant phenotypes, and 368 and 1041 unique proteins were dormancy genotype-specific in embryo and aleurone, respectively. Quantitative proteome analysis in red seeded population resulted in total over 7200 and 3580 proteins identified with high confidence in embryo and aleurone, respectively. Proteomic signatures associated with dormancy phenotype were more evident in white seeded population, whereas genotype-specific and after-ripening induced changes were found in both populations. In dormant embryos, significant phenotype-specific changes were found for proteins involved in redox controlling system, signaling associated with flowering, phytohormones and lipid second messengers, development and growth repression, cell cycle control and epigenetic regulation of gene expression, translational dynamics, cell wall metabolism, vesicle transport, and ubiquitin 26S proteasome pathway. In embryos with non-dormant phenotype energy metabolism showed high capacity for the provision of NADPH reducing equivalents, pyruvate and TCA cycle intermediates for biosynthetic processes. Pathways for energy provision in non-dormant aleurone showed increased flux through the glycolytic pathway, high metabolic network flexibility, and an important role of inorganic pyrophosphate metabolism as an alternative energy donor. Further analysis of the iTRAQ-identified differentially expressed proteins in known QTL regions for PHS tolerance revealed potential candidate genes underlying the QTLs.