Analisi del contenuto di istoni H1 in nuclei di radici infettate o no con un fungo micorrizico arbuscolare

The chromatin structure of nuclei extracted from leek roots, colonized or not by the arbuscular mycorrhizal fungus Glomus mosseae, was analyzed with immunolabelling of histone H1 and its quantification via flow cytometry. Chromatin was also examined with affinity cromatography, in order to evaluate the exposition of the -SH groups of the nucleosomes. The results indicated a clear reduction of fluorescence in the mycorrhizal nuclei, suggesting that the increase in chromatin decondensation, well documented in the literature, could be mediated by H1. Biochemical data confirmed the decrease of chromatin condensation and showed that, in the DNA of mycorrhizal plants, a larger number of nucleosomes in active conformation (-SH groups exposed) was present, in comparison with control plants.