Rising CO2 concentration altered wheat grain proteome and flour rheological characteristics

Wheat cv. H45 was grown under ambient CO₂ concentration and Free Air CO₂ Enrichment (FACE; e[CO₂], ~550 μmol CO₂ mol⁻¹). The effect of FACE on wheat grain proteome and associated changes in the flour rheological properties was investigated. A comparative proteomic analysis was performed using 2-D-DIGE followed by MALDI/TOF-MS. Total grain protein concentration was decreased by 9% at e[CO₂]. Relative abundance of three high molecular weight glutenin sub units (HMW-GS) were decreased at e[CO₂]. In contrast, relative abundance of serpins Z1C and 1-Cys peroxiredoxin was increased at e[CO₂]. Elevated [CO₂] also decreased the bread volume (by 11%) and dough strength (by 7%) while increased mixing time. However, dough extensibility and dough stability were unchanged at elevated [CO₂]. These findings suggest that e[CO₂] has a major impact on gluten protein concentration which is associated lower bread quality at e[CO₂].