CO2 treatment increases glucosinolate hydrolysis products in two Arabidopsis thaliana accessions

Abstract

Brassicales include many vegetables of nutritional interest because the hydrolysis products of their phytochemicals, the glucosinolates, have health-promoting properties. So far, the impact of rising CO2 concentrations on glucosinolates and their hydrolysis is unclear. Applying a modified atmosphere, we exposed two Arabidopsis thaliana accessions that differ in their glucosinolate hydrolysis behavior, namely Hi-0 and Bur-0, to elevated CO2 concentrations. Glucosinolates and their hydrolysis products were analyzed using UHPLC-DAD-MS and GC-MS.

CO2 treatment increased indicators of primary production, such as biomass, leaf area and electron transport rate, and increased gluco-sinolate levels in Bur-0, but not Hi-0. Significantly, released glucosinolate hydrolysis product levels increased by up to 122% in Bur-0 due to increased epithionitrile formation. Likewise, in Hi-0 glucosinolate hydrolysis product levels increased after CO2 treatment by up to 67%, caused by enhanced nitrile and to some extent isothiocyanate formation. In addition, more alkenyl rather than alkyl glucosinolates were formed in Bur-0 under elevated CO2, thus changing the glucosinolate profile compositions. As CO2 treatment enhanced primary production but also overall glucosinolate hydrolysis pro-duct formation, it is conceivable to recycle excess CO2 by using it as supplement greenhouse gas to produce high-quality food.