ibclogo XVI International Botanical Congess

Abstract Number: 4024
Poster No. = 1790


ENVIRONMENTAL INFLUENCE ON REPETITIVE DNA BEHAVIOUR: THE LEAD/FUNARIA H. SYSTEM


1Bassi P., 2Basile A., 2Castaldo-Cobianchi R., 3Ferraro M., 3Nardone A.M., 3Predazzi V., 1Dept. of Plant Biol., Univ. of Rome, 2Dept. of Plant Biol., Univ. of Naple, 3Dept. of Gen. and Mol. Biol., Univ. of Rome


Last year?s research has provided evidence that repetitive fraction of plant genome may by susceptible to environmental stress. We investigated this problem in the in vitro controlled system Lead/Funaria h. showing that lead is able to induce selective amplification of G+C rich repetitive DNA sequences adjacent to the nucleolar region (Bassi et al., Protoplasma, 188: 104-108, 1995). In the present work the autors examined to a great depth the problem by X-ray TEM microanalysis, in situ hybridization and molecular characterization. The obtained data seem to indicate that nucleus is one of the target of lead and that at least part of repetitive DNA sequences lead-susceptible might belong to the ribosomal fraction of genome. Therefore we are performing FISH using as probe different portions of rDNA of Funaria h. The same probes are also tested on genomic DNA extracted from stressed and unstressed individuals. Preliminary data will be discussed in detail.

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