Monitoring of isothiocyanates emanating from Arabidopsis thaliana upon paraquat spraying

Arabidopsis thaliana plants were sprayed with the superoxide-generating her bicide paraquat. The headspace of sprayed plants was characterized by a num ber of compounds, which were absent in the headspace of untreated plants. T hey were identified as isothiocyanates (ITCs) with 4-methylthiobutyl isothi ocyanate as main compound. After identification, a GC-system, based on PDMS sorption, was used to continuously monitor the ITC emissions. The specific ity of isothiocyanate emission was also determined by subjecting the Arabid opsis thaliana plants to in vitro mechanical wounding. Again, 4-methylthiob utyl isothiocyanate was the main component, but the emission profile was co mpletely different since the compound was emitted immediately, i.e., during wounding itself. (C) 2001 Elsevier Science B.V. All rights reserved.