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Specific hypomethylation of DNA is induced by heavy metals in white clover and industrial hemp
Author(s) -
Aina Roberta,
Sgorbati Sergio,
Santagostino Angela,
Labra Massimo,
Ghiani Alessandra,
Citterio Sandra
Publication year - 2004
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2004.00343.x
Subject(s) - dna methylation , methylation , biology , trifolium repens , dna , polymerase chain reaction , botany , microbiology and biotechnology , genetics , gene , gene expression
The present study was to assess the effect of heavy metal stress on the DNA methylation of a metal‐sensitive plant, Trifolium repens L. and of a metal‐tolerant plant, Cannabis sativa L. The changes in the level of 5‐methylcytosine (5mC) in the root DNA of plants grown on soils contaminated with different concentrations of Ni 2+ , Cd 2+ and Cr 6+ compared with that of untreated plants, were determined by immunolabelling with a monoclonal antibody, using the Slot‐Blot technique. Results showed that DNA of hemp control plants was about three times more methylated than clover DNA, for the same amount of root DNA. Heavy metal treatments induced a global dose‐dependent decrease of 5mC content, both in hemp and clover, ranging from 20 to 40%. Changes in methylation pattern of 5′‐CCGG‐3′ containing sequences were investigated by methylation‐sensitive amplification polymorphism (MSAP) technique. Control plants of the same species showed a very similar pattern, suggesting that, in normal condition, methylation involves precise sites. Heavy metals induced DNA methylation changes mainly related to hypomethylation events. These variations were not randomly directed but involved specific DNA sequences, since the detected polymorphisms were the same in all the plants analysed for each treatment.