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Title: Plasticity of Epigenetics and Chromatin structure: concerted strategies for enhanced plant tolerance under stress

Speaker: Ana Santos

Affiliation: Plant Functional Genomics Lab, ITQB NOVA

Abstracts: The organization pattern of chromatin within interphase nucleus together with DNA methylation and histone modifications can influence gene expression and therefore also plant phenotypes. Environmental stresses are often associated with extensive chromatin rearrangements and modifications of epigenetic levels and patterns. We showed that abiotic stress conditions including cold, heat and mild salinity as well as induced DNA hypomethylation can cause interphase chromatin structural changes in rice rDNA Loci. The variations occurring on global DNA methylation levels in response to salt stress were tissue- and genotype-dependent. Stress-tolerant plants can allow unveiling connections between specific epigenetic modifications and stress tolerance capacity. The salt-tolerant rice variety Pokkali was remarkable in its ability to quickly relax DNA methylation in response to salt stress and furthermore, the MeDIP-Seq analysis revealed a set of Differentially Methylated Regions (DMRs) between control and salt stress. The DNA methylation patterns of DMRs revealed a general tendency for demethylation events under salt. A deeper knowledge of the mechanisms underlying epigenetic regulation contributes to uncover new players in the regulation of stress-responsive genes and new target regions with potential application to enhance plant tolerance to stress.