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:Apple (Malus x domestica Borkh.) is a model fruit species to study the metabolic changes occurring at the onset of ripening as well the physiological mechanism governed by the hormone ethylene. In this survey, to dissect the climacteric interplay in apple, a multidisciplinary approach was employed. To this end, a comprehensive analysis of gene expression together with the investigation of several physiological entities (texture, volatilome and polyphenolic compounds) was carried out throughout fruit development and ripening. The transcriptomic profiling was conducted with two microarray platforms, a custom array dedicated to fruit ripening pathways (iRIPE) and a whole genome array specifically enriched of ripening related genes for apple (WGAA). The transcriptomic and phenotypic changes following the application of 1-methylcyclopropene (1-MCP), an ethylene inhibitor, were also highlighted. The suppression of ethylene modified and delayed the ethylene receptors turnover, leading to important modifications in the overall fruit physiology. The integrative comparative network analysis showed both negative and positive correlations between ripening related transcripts and accumulation of specific metabolites or texture components. The ripening distortion caused by the inhibition of the ethylene perception besides affecting the ethylene and texture control, stimulated the de-repression of auxin related genes, transcription factors and photosynthethic genes. In the end, the comprehensive repertoire of results obtained here step forwards in the elucidation of the multi-layered control of ethylene, hypothesizing a possible hormonal cross-talk coupled with a transcriptional regulation. 48 samples analyzed; 8 stages have been identified over the fruit development and ripening (from flower to post harvest ripening) of apple fruit belonging to two apple cultivars (Golden Delicious and Granny Smith), ending with 16 samples (3 replacates for each sample)
Project description:Apple (Malus x domestica Borkh.) is a model fruit species to study the metabolic changes occurring at the onset of ripening as well the physiological mechanism governed by the hormone ethylene. In this survey, to dissect the climacteric interplay in apple, a multidisciplinary approach was employed. To this end, a comprehensive analysis of gene expression together with the investigation of several physiological entities (texture, volatilome and polyphenolic compounds) was carried out throughout fruit development and ripening. The transcriptomic profiling was conducted with two microarray platforms, a custom array dedicated to fruit ripening pathways (iRIPE) and a whole genome array specifically enriched of ripening related genes for apple (WGAA). The transcriptomic and phenotypic changes following the application of 1-methylcyclopropene (1-MCP), an ethylene inhibitor, were also highlighted. The suppression of ethylene modified and delayed the ethylene receptors turnover, leading to important modifications in the overall fruit physiology. The integrative comparative network analysis showed both negative and positive correlations between ripening related transcripts and accumulation of specific metabolites or texture components. The ripening distortion caused by the inhibition of the ethylene perception besides affecting the ethylene and texture control, stimulated the de-repression of auxin related genes, transcription factors and photosynthethic genes. In the end, the comprehensive repertoire of results obtained here step forwards in the elucidation of the multi-layered control of ethylene, hypothesizing a possible hormonal cross-talk coupled with a transcriptional regulation. whole genome array specifically enriched of ripening related genes for apple (WGAA) with two cultivars (Golden Delicious and Granny Smith)
Project description:Apple (Malus x domestica Borkh.) is a model fruit species to study the metabolic changes occurring at the onset of ripening as well the physiological mechanism governed by the hormone ethylene. In this survey, to dissect the climacteric interplay in apple, a multidisciplinary approach was employed. To this end, a comprehensive analysis of gene expression together with the investigation of several physiological entities (texture, volatilome and polyphenolic compounds) was carried out throughout fruit development and ripening. The transcriptomic profiling was conducted with two microarray platforms, a custom array dedicated to fruit ripening pathways (iRIPE) and a whole genome array specifically enriched of ripening related genes for apple (WGAA). The transcriptomic and phenotypic changes following the application of 1-methylcyclopropene (1-MCP), an ethylene inhibitor, were also highlighted. The suppression of ethylene modified and delayed the ethylene receptors turnover, leading to important modifications in the overall fruit physiology. The integrative comparative network analysis showed both negative and positive correlations between ripening related transcripts and accumulation of specific metabolites or texture components. The ripening distortion caused by the inhibition of the ethylene perception besides affecting the ethylene and texture control, stimulated the de-repression of auxin related genes, transcription factors and photosynthethic genes. In the end, the comprehensive repertoire of results obtained here step forwards in the elucidation of the multi-layered control of ethylene, hypothesizing a possible hormonal cross-talk coupled with a transcriptional regulation.
Project description:Apple (Malus x domestica Borkh.) is a model fruit species to study the metabolic changes occurring at the onset of ripening as well the physiological mechanism governed by the hormone ethylene. In this survey, to dissect the climacteric interplay in apple, a multidisciplinary approach was employed. To this end, a comprehensive analysis of gene expression together with the investigation of several physiological entities (texture, volatilome and polyphenolic compounds) was carried out throughout fruit development and ripening. The transcriptomic profiling was conducted with two microarray platforms, a custom array dedicated to fruit ripening pathways (iRIPE) and a whole genome array specifically enriched of ripening related genes for apple (WGAA). The transcriptomic and phenotypic changes following the application of 1-methylcyclopropene (1-MCP), an ethylene inhibitor, were also highlighted. The suppression of ethylene modified and delayed the ethylene receptors turnover, leading to important modifications in the overall fruit physiology. The integrative comparative network analysis showed both negative and positive correlations between ripening related transcripts and accumulation of specific metabolites or texture components. The ripening distortion caused by the inhibition of the ethylene perception besides affecting the ethylene and texture control, stimulated the de-repression of auxin related genes, transcription factors and photosynthethic genes. In the end, the comprehensive repertoire of results obtained here step forwards in the elucidation of the multi-layered control of ethylene, hypothesizing a possible hormonal cross-talk coupled with a transcriptional regulation.
Project description:Molecular events regulating apple fruit ripening and sensory quality are largely unknown. Such knowledge is essential for genomic-assisted apple breeding and postharvest quality management. In this study, a parallel transcriptome profile analysis, scanning electron microscopic (SEM) examination and systematic physiological characterization were performed on two apple cultivars, Honeycrisp (HC) and Cripps Pink (CP), which have distinct ripening features and texture attributes. Systematic physiological characterization of fruit ripening based on weekly maturity data indicated substantial differences in fruit crispness and firmness at comparable ripening stages. SEM images of fruit cortex tissues prepared from fruits with equivalent maturity suggested that the cell wall thickness may contribute to the observed phenotypes of fruit firmness and crispness. A high-density long-oligo apple microarray consisting of duplex 190,135 cross-hybridization-free 50-70-mer isothermal probes, and representing 23,997 UniGene clusters, was manufactured on a Nimblegen array platform. Transcriptome profiling identified a total of 1793 and 1209 UniGene clusters differentially expressed during ripening from cortex tissues of HC and CP, respectively. UniGenes implicated in hormone metabolism and response, cell wall biosynthesis and modification and those encoding transcription factors were among the prominent functional groups. Between the two cultivars, most of the identified UniGenes were similarly regulated during fruit ripening; however, a short list of gene families or specific family members exhibited distinct expression patterns between the two cultivars, which may represent candidate genes regulating cultivar-specific apple fruit ripening patterns and quality attributes.
Project description:Molecular events regulating apple fruit ripening and sensory quality are largely unknown. Such knowledge is essential for genomic-assisted apple breeding and postharvest quality management. In this study, a parallel transcriptome profile analysis, scanning electron microscopic (SEM) examination and systematic physiological characterization were performed on two apple cultivars, Honeycrisp (HC) and Cripps Pink (CP), which have distinct ripening features and texture attributes. Systematic physiological characterization of fruit ripening based on weekly maturity data indicated substantial differences in fruit crispness and firmness at comparable ripening stages. SEM images of fruit cortex tissues prepared from fruits with equivalent maturity suggested that the cell wall thickness may contribute to the observed phenotypes of fruit firmness and crispness. A high-density long-oligo apple microarray consisting of duplex 190,135 cross-hybridization-free 50-70-mer isothermal probes, and representing 23,997 UniGene clusters, was manufactured on a Nimblegen array platform. Transcriptome profiling identified a total of 1793 and 1209 UniGene clusters differentially expressed during ripening from cortex tissues of HC and CP, respectively. UniGenes implicated in hormone metabolism and response, cell wall biosynthesis and modification and those encoding transcription factors were among the prominent functional groups. Between the two cultivars, most of the identified UniGenes were similarly regulated during fruit ripening; however, a short list of gene families or specific family members exhibited distinct expression patterns between the two cultivars, which may represent candidate genes regulating cultivar-specific apple fruit ripening patterns and quality attributes. Using a single color labeling system, a total of 24 microarray slides were utilized, one for each cortex tissue sample, for transcriptome profiling analysis. 2 cultivars x 3 developmental stages x 4 biological replicates.