Interaction between atmospheric CO2 and glucosinolates in broccoli.
Total and individual glucosinolate contents of broccoli cv Marathon were assessed at ambient CO2 (430 – 480 ppm) and elevated atmospheric CO2 (685 – 820 ppm) to determine the ecological relationship between changing atmospheric CO2 concentrations and phytochemicals. Elevated atmospheric CO2 concentration had a differing effect on individual glucosinolates and glucosinolate groups. Total glucosinolate content increased at elevated atmospheric CO2 concentration as a result of a strong increase in both methylsulfinylalkyl glucosinolates glucoraphanin and glucoiberin. In contrast, indole glucosinolates simultaneously decreased predominantly due to a reduction of glucobrassicin and 4-methoxy-glucobrassicin contents. We conclude that changes in N content and N/S ratios as well as alterations in photochemical processes at elevated atmospheric CO2 concentration could influence the Brassica’s total and individual glucosinolates contents as demonstrated for broccoli. Our results provide clear evidence that in respect to predicted elevation of atmospheric CO2 concentrations, the secondary plant metabolism is affected by increasing CO2 levels as demonstrated by analyzing glucosinolate content.
Schonhof, I.; Kläring, H.-P.; Krumbein, A.; Schreiner, M. 2007. Interaction between atmospheric CO2 and glucosinolates in broccoli. Journal of Chemical Ecology 33, 105-114.