Leaf Proteome Responses of Wheat (Triticum aestivum L.) to Elevated Atmospheric Carbon Dioxide during Early Vegetative Growth

Abstract

The impact of rising atmospheric carbon dioxide [CO2] on the proteome of the growing leaf blade was investigated using two winter wheat cultivars: Kukri and RAC875, in the early vegetative stage. Two wheat genotypes were grown at ambient (400 µmol mol-1 ) and elevated (700 µmol mol-1 ) [CO2] in controlled environmental conditions. At 42 days after planting (DAP), total dry mass, carbon and nitrogen content, and gas exchange measurements were determined in both CO2 treatments and data were analysed using SPSS statistical software version 23 (IBM, Armonk, NY, USA). Elevated [CO2] increased the rate of photosynthesis and biomass production in Kukri by 16.4 % and 32.6 %, respectively, when compared with 20 % and 48% in RAC875. The nitrogen and protein concentrations in the expanding leaf blades of both cultivars determined through the CN analyzer were high, and RAC875 showed the highest nitrogen percentage (56.3%). Results of the comparative proteomics analysis carried out through liquid chromatography-mass spectrometry (LC-MS/MS) analysis showed that leaf proteome responses at elevated [CO2] were genotype dependent, and the proteome composition has been altered at elevated [CO2]. Most of the differentially expressed proteins at elevated [CO2] belonged to carbon metabolism, energy pathways, protein synthesis, and cell cycle functions.