DIFFERENTIAL EXPRESSION OF GENES-CODING FOR ABC TRANSPORTERS AFTER TREATMENT OF ARABIDOPSIS-THALIANA WITH XENOBIOTICS

ATP-binding cassette (ABC) transporters are thought to be involved in many cellular detoxification mechanisms, Performing a BLAST search, we found four distinct expressed sequence tags (EST) of Arabidopsis thal iana highly similar to the human and fungal glutathione-conjugate ABC transporters. We studied the expression of the corresponding gents in response to various xenobiotics in an effort to gain information on th eir function, The abundance of transcripts corresponding to one of the genes (EST1) was not affected by the various compounds tested, wherea s the abundance of transcripts corresponding to the other three genes (EST2, EST3, EST4) was increased by 1-chloro-2,4-dinitrobenzene, primi sulfuron and IRL 1803, Treatment of Arabidopsis with either primisulfu ron or IRL 1803 resulted in a more than 40-fold increase in EST2-speci fic transcripts. (C) 1997 Federation of European Biochemical Societies .