Trichloroacetic acid of different origin in Norway spruce needles and chloroplasts

24 May 2010

Trichloroacetic acid (TCA), a secondary atmospheric pollutant, is also formed in forest soil and thus ranked among natural organohalogens. The observed biooxidation of atmospheric tetrachloroethene (PER) to TCA in chloroplasts has led to the investigation of the mode of action of TCA in spruce needles, since TCA is also accumulated in the needles after its rapid uptake from soil by roots. Being phytotoxic, TCA considerably influences conifers by affecting their photosynthetic apparatus. We examined the transport of TCA from soil into chloroplasts in order to compare the effects of TCA on conifers from both sources, i.e. endogenously produced within chloroplasts or taken up by roots. The influence of TCA formed in chloroplasts was found to be much more adverse than that of “soil” TCA.