Project description:Genome-wide DNA methylation analysis between long-term in vitro shoot culture and acclimatized apple plants DNA methylation is a process of epigenetic modification that can alter the functionality of a genome. Using whole-genome bisulfite sequencing, this study quantify the level of DNA methylation in the epigenomes of two diploid apple (Malus x domestica) scion cultivars ('McIntosh' and 'Húsvéti rozmaring') derived from three environmental conditions: in vivo mother plants in an orchard, in vitro culture, and acclimatized in vitro plants. The global DNA methylation levels were not dependent on the source of plant material. Significant differences in DNA methylation were identified in 586 out of 45,116 genes, including promoter and coding sequences, and classified as differentially methylated genes (DMGs). Differential methylation was visualised by an MA plot and functional genomic maps were established for biological processes, molecular functions and cellular components. Considering the DMGs, in vitro tissue culture resulted in the highest level of methylation, which decreased after acclimatization and tended to be similar to that in the mother tree. Methylation patterns of the two scions differed, indicating cultivar-specific epigenetic regulation of gene expression during adaptation to various environments. After selecting genes that displayed differences larger than ±10% in CpG and CHG contexts, or larger than ±1.35% in the CHH context from among the DMGs, they were annotated in Blast2GO v5.1.12 for Gene Ontology. These DNA methylation results suggest that epigenetic changes may contribute to the adaptation of apple to environmental changes by modifying gene expression.
Project description:Chloroplasts were purified by centrifugation in Percoll gradient from low temperature (4 C), control (22 C) and high temperature (30 C) grown Malus x domestica microshoots. The proteins were digested using filter aided sample processing (FASP) and analyzed using nano-LC MS/MS. Constant scan rate of 2 Hz and range from 100 to 2,200 m/z was used for the MS spectra acquisition. Data-dependent auto-MS/MS method (Compass 1.5 acquisition and processing software, Bruker Daltonics) was used for selecting the 10 most abundant precursor ions for fragmentation. The MS/MS summation time was adjusted based on precursor intensity within the range 1-10 Hz. Active exclusion of already analyzed precursors was used with a release time of 30 s. Precursor ion isolation window and the CID collision energy were adjusted between 3-9 Th and 34-55 eV as a function of the m/z value, respectively. The data files (9 low temperature samples, 12 control samples and 9 high temperature sampes) are described in the "metadata.txt" file.
