Growth, physiological and proteomic responses in field grown wheat varieties exposed to elevated CO₂ under high...

The present study investigated growth, biochemical, physiological, yield and proteomic changes in 3 wheat varieties exposed to elevated CO₂ (515 ppm) in a background of high ambient ozone in field. Ethylenediurea (EDU) was used as antiozonant. Average ozone concentration was 59 ppb and was sufficient enough to exert phytotoxic effects. Elevated carbon dioxide (eCO₂) and EDU application individually or in combination negated the adverse effects of ozone by modulating antioxidants and antioxidative enzymes. Differential leaf proteomics revealed that at vegetative stage major changes in protein abundance were due to EDU treatment (47, 52 and 41 proteins in PBW-343, LOK1 and HD-2967, respectively). Combined treatment of eCO₂ and EDU was more responsible for changes in 37 proteins during flowering stage of PBW-343 and LOK1. Functional categorization revealed more than 60% differentially abundant protein collectively belonging to carbon metabolism, protein synthesis assembly and degradation and photosynthesis. At both the growth stages, LOK1 was more responsive to eCO₂ and combined treatment (eCO₂ + EDU). HD-2967 was more positively responsive to EDU and combined treatment. eCO₂ in combination of EDU protected these varieties against high ambient O₃.