Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Oman → The adaptation of medicago spp to salt stress involves changes in DNA methylation

Sultan Qaboos University (2016)

The adaptation of medicago spp to salt stress involves changes in DNA methylation

Abbas Abdul HadiAl-Lawati

Titre : The adaptation of medicago spp to salt stress involves changes in DNA methylation

Auteur : Abbas Abdul HadiAl-Lawati

Université de soutenance : Sultan Qaboos University

Grade : Doctor of Philosophy in Plant Molecular Biology 2016

Résumé partiel
In this study, methylation-sensitive amplified polymorphism (MSAP) analysis was used to assess cytosine methylation levels in alfalfa (Medicago spp) roots exposed to increasing Naci concentrations (0.0, 8.0, 12.0, and 20.0 dS/m). Eleven indigenous landraces were analyzed, in addition to a salt-tolerant genotype that was used as a control. There was a slight increase in DNA methylation upon exposure to high levels of soil salinity. Phylogenetic analysis using MSAP showed epigenetic variation within and between the alfalfa landraces when exposed to saline conditions. Based on MSAP and enzyme-linked immunosorbent assay results, we found that salinity increased global DNA methylation status, particularly in plants exposed to the highest level of salinity (20 dS/m). Quantitative reverse transcription-polymerase chain reaction indicated that this might be mediated by the overexpression of methyltransferase homolog genes after exposure to saline conditions. Differential genome-wide DNA methylation quantification was carried out by bisulfide conversion and Illumina next-generation sequencing technologies using DNA samples extracted from root tissues exposed to normal conditions and to salinity stress. Around 50 million differentially methylated sites (DMSS) was recognized, 15% of which were significantly (p <0.5) altered in response to salinity. The analysis showed that 77.0% of the DMSs contexts were mCHH while only 9.1% and 13.9% were occupied by the mCHG and mCG contexts, respectively. There was a considerable increase in the DNA methylation levels in all sequence contexts, ranging from 11.7% to 15.3% due to salinity stress. This information was confirmed by mass spectrometry analysis, where the results showed there was a substantial increase of about 19.4% in the total 5mdC levels in response to salinity treatment. Few genes have their DMSs simultaneously distributed along the different structures of a gene ; however, there was a contrariwise relationship between the mCG and the mCHH methylation profiles in the promoter and exon regions of the top 2000 DMSs when plants were grown under saline

Présentation (SHUAA)

Annonce (Almandumah)

Page publiée le 4 juin 2022