Project description:The main objective of this analysis was to sequence the epigenome of the Apple (Malus domestica) doubled haploid 'Golden Delicious' tree. Our secondary objective was to identify differentially methylated regions between DNA purified from leaves and young fruits.
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:Effect of the presence of fruits on the expression of genes possibly involved in floral induction in the terminal meristem of spur bourse shoot. Investigation on mecanisms involved in Biennial Bearing in mature apple trees cultivar Royal Gala.
Project description:The main objective of this analysis was to sequence the epigenome of two apple (Malus domestica) doubled haploid 'Golden Delicious' fruits (GDDH13 and GDDH18). Our secondary objective was to identify differentially methylated regions between DNA purified from the GDDH13 genotype and the GDDH18 genotypes at two developmental stages.
Project description:Effect of the presence of fruits on the expression of genes possibly involved in floral induction in the terminal meristem of spur bourse shoot. Investigation on mecanisms involved in Biennial Bearing in mature apple trees cultivar Royal Gala. Two-condition experiment : 'ON' trees (unthinned control) & 'OFF' trees (deflowered) for comparison. Three comparisons at sampling dates : 28, 48 and 119 days after full bloom (DAFB). Two dye switch biological replicates for each treatment and sampling date.
Project description:Ontogenic scab resistance in apple leaves and fruits is a horizontal resistance against the plant pathogen VenturiaM- inaequalis and is expressed as decrease of disease symptoms and incidence with the ageing of the leaves. Several studies at biochemical level tried to unveil the nature of this resistance, however without any conclusive results. We decided therefore to investigate the genetic origin of this phenomenon by performing a full quantitative trascriptome sequencing and comparison of young (susceptible) and old (ontogenic resistant) leaves, infected or not with the pathogen. Two time points at 72 and 96 hours post inoculation were chosen for RNA sampling and sequencing. Comparison between the different conditions (young and old leaves, inoculated or not) should allow finding genes differentially expressed which may represent different induced plant defense reaction leading to ontogenic resistance or be the cause for a constitutive (not inoculated with the pathogen) shift toward resistance in old leaves. Differentially expressed genes were then characterized for their function by homology to A.M- thaliana and other plantsM-^R genes, particularly looking for genes involved in pathways already suspected of appertaining to ontogenic resistance in apple or other hosts, or to plant defense mechanisms in general.
Project description:Bitter pit is the most important physiological disorder affecting apples. In order to ascertain the genetic bases of its incidence in apple fruit, a mapping population of ‘Braeburn’ (susceptible to bitter pit) × ‘Cameo’ (resistant to bitter pit) cultivars was used to map the trait over two growing seasons. RNA-Seq on pools of RNA extracted from fruits of three resistant and three susceptible to bitter pit progenies at post-fertilization and full maturity stages, permitted us to identify a number of candidate genes underlying genetic resistance/susceptibility to bitter pit.
Project description:Apple is typically stored under low temperature and controlled atmospheric conditions to ensure a year round supply of high quality fruit for the consumer. During storage, losses in quality and quantity occur due to spoilage by postharvest pathogens. One important postharvest pathogen of apple is Botrytis cinerea. The fungus is a broad host necrotroph with a large arsenal of infection strategies able to infect over 1,400 different plant species. We studied the apple-B. cinerea interaction to get a better understanding of the defense response in apple. We conducted an RNAseq experiment in which the transcriptome of inoculated and non-inoculated (control and mock) apples was analyzed at 0, 1, 12 and 28 h post inoculation. Our results show extensive reprogramming of the apple's transcriptome with about 28.9 % of expressed genes exhibiting significant differential regulation in the inoculated samples. We demonstrate the transcriptional activation of pathogen-triggered immunity and a reprogramming of the fruit’s metabolism. We demonstrate a clear transcriptional activation of secondary metabolism and a correlation between the early transcriptional activation of the mevalonate pathway and reduced susceptibility, expressed as a reduction in resulting lesion diameters. This pathway produces the building blocks for terpenoids, a large class of compounds with diverging functions including defense. 1-MCP and hot water dip treatment are used to further evidence the key role of terpenoids in the defense and demonstrate that ethylene modulates this response.
Project description:Apple pedicel vascular development array Twelvet apple samples. Biological replicates: 2 for each sample, independently grown and harvested.