Atmospheric carbon dioxide changes photochemical activity, soluble sugars and volatile levels in broccoli (Brassica oleracea var. italica).
Atmospheric carbon dioxide (CO2) concentration is an environmental factor currently undergoing dramatic changes. The objective of the present study was to determine the effect of doubling the ambient CO2 concentration on plant photochemistry as measured by photochemical quenching coefficient (qP), soluble sugars and volatiles in broccoli. Elevated CO2 concentration increased qP values in leaves by up to 100% and 89% in heads, while glucose and sucrose in leaves increased by about 60%. Furthermore, in broccoli heads elevated CO2 concentration induced approximately a two-fold increase in concentrations of three fatty acid-derived C7 aldehydes ((E)-2-heptenal, (E,Z)-2,4-heptadienal, (E,E)-2,4-heptadienal), two fatty acid-derived C5 alcohols (1-penten-3-ol, (Z)-2-pentenol), and two amino acid-derived nitriles (phenyl propanenitrile, 3-methyl butanenitrile). In contrast, concentrations of the sulfur-containing compound 2-ethylthiophene and C6 alcohol (E)-2-hexenol decreased. Finally, elevated CO2 concentration increased soluble sugar concentrations due to enhanced photochemical activity in leaves and heads, which may account for the increased synthesis of volatiles.
Krumbein, A.; Kläring, H.P.; Schonhof, I.; Schreiner, M. 2010. Atmospheric carbon dioxide changes photochemical activity, soluble sugars and volatile levels in broccoli (Brassica oleracea var. italica). Journal Agricultural and Food Chemistry 58 (6), 3747–3752.