Barley seeds are the most important material for malting and brewing, and it is the fourth major cereal being produced globally. Improvements in malting quality are crucial for Western Australian barley cultivars to compete in export markets. Genetic background and environment are major factors influencing malting characteristics of barley grains. In this project three groups of near isogenic barley lines (NILs) developed by Edstar Genetics, have been studied. These lines were grown in three locations (Toodyay, Mingenew, and Munglinup) across Western Australia in 2019 and commercially malted. The objective of this work was to investigate the effect of genetic background and growing environment on the grain proteomes by using liquid chromatography-mass spectrometry. To study grain proteomes, protein identification was performed by data-dependent acquisition (DDA) and quantitation was conducted utilising Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS). A total of 1,517 proteins were identified and 920 proteins were quantified. Proteomics-malting relation data analysis indicated that malt yield, free amino nitrogen and test weight are related traits in the experimented samples.
It has been found that 203 proteins affect malt yield and among these, there are 9 differentially abundant proteins according to growing location independent of the genetic background. Gene Ontology (GO) analysis indicated that these proteins were stimulus-responsive proteins or proteins with catalytic activity. When comparing the growing locations, there were differences observed in terms of precipitation and temperature. The proteins identified and quantified in this study are being reviewed for their potential as markers for malting quality prediction to inform barley breeding programs and to develop cultivars less dependent or impacted by the environment in which barley is cultivated.