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Publicação
Abiotic stress and induced DNA hypomethylation cause interphase chromatin structural changes in rice rDNA loci
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Orientador(es)
Resumo(s)
Global climate change, i.e. higher and more variable temperatures,
and a gain in soil salinity are increasing plant
stress with direct consequences on crop yield and quality
levels. Rice productivity is strongly affected by abiotic stress
conditions. The regulation of chromatin structure in response
to environmental stress is poorly understood. We investigated
the interphase chromatin organization from rice
plants in non-stress versus stress conditions. We have used a
cytogenetic approach, based on fluorescence in situ hybridization
(FISH) with 45S, 5S rDNA and centromeric probes on
rice tissue sections. The abiotic stress conditions included
cold, heat and mild salinity and were applied during seed
germination. In contrast to cold, saline and heat stresses
caused extensive decondensation of 45S rDNA chromatin
and also an increase in the distance between the 2 homologous
5S rDNA loci. 5-Azacytidine (5-AC), a DNA hypomethylating
drug, greatly increased 45S rDNA chromatin decondensation
and interestingly was able to induce polarization
of centromeres in rice interphase nuclei. The abiotic stresses
tested did not perturb the spatial position of centromeres, typically with circular arrangement around the nucleolus.
The results suggest a role for chromatin plasticity in a world
of climate changes.
Descrição
Palavras-chave
Abiotic stress 5-Azacytidine Chromatin organization rDNA Rice
Contexto Educativo
Citação
Cytogenetic and Genome Research, 132, 297-303