15th May 2026

Michelle Colgrave & Clare O’Lone, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science. This seminar describes a study which used quantitative proteomics to investigate why an InterGrain barley breeding line, IGB1467, achieves acceptable grain modification during malting with less water than the control variety, Flinders. Time-resolved sampling across pilot malting, combined with discovery and targeted LC–MS/MS, identified a significantly lower abundance of aquaporin water channel proteins in IGB1467, particularly TIP3. Reduced aquaporin abundance is consistent with the lower steeping water requirement and improved water-use efficiency. The broader proteomic dataset indicates that IGB1467 maintains germination under constrained hydration through a shift toward fermentative metabolism and a low-oxygen escape–like growth strategy. This is associated with both increased oxidative stress and continued metabolic demand. Together, these processes contribute to measurable changes in malt quality, including reduced free amino nitrogen, lower diastatic power, and elevated wort β-glucan, reflecting both oxidative pressure and sustained reserve mobilisation. These findings define an efficiency–quality trade-off associated with aquaporin abundance and growth strategy, providing a proteomic framework to inform more balanced trait selection in barley breeding.