UV-C RADIATION INDUCES APOPTOTIC-LIKE CHANGES IN ARABIDOPSIS-THALIANA

With a view to studying programmed cell death in plants at the molecul ar level, we report here for the first time that apoptotic-like change s are induced by UV radiation in plant nuclei. In Arabidopsis thaliana seedlings a UV-C dose of 10-50 kJ/m(2) induces an oligonucleosomal DN A fragmentation which is reminiscent of the apoptotic DNA ladder descr ibed in animal cells, This DNA fragmentation was also detected in situ in protoplast nuclei as soon as 2 h after UV-C treatment. Moreover, U V-C induced a nuclear morphology characteristic of animal apoptotic nu clei. We propose that UV-C induction constitutes a powerful tool to co mpare the cellular response to irreversible UV damage in plants to tha t in animals and to study programmed cell death in A. thaliana, (C) 19 98 Federation of European Biochemical Societies,