Project description:In order to know more about the expression levels of aroma-related genes involved in the metabolic pathways, transcriptome sequencing of Granny Smith and Jonagold apples was conducted utilizing the Illumina platform. Our study provides new insights on the understanding of transcriptional regulatory mechanisms associated with aroma volatiles formation in apples.
Project description:Apples (Malus x domestica Borkh, Gala variety) grown in commercial orchards were harvested at maturity and maintained 2 months in cold storage with or without 1-MCP treatment.
Project description:Granny Smith apples (Malus x domestica Borkh) were harvested at early physiological mature stage in 2014, 2015 and 2017 and phenotyped for scald incidence after long time cold storage. Differential analyses were set-up for peel samples collected at harvest between fruit batches with low or high scald incidence.
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:V. inaequalis causes apple scab disease, the most economically important disease of apples. In this study, we generated a comprehensive RNA-seq transcriptome of V. inaequalis during host colonization of apple, with six in planta time points (12hpi, 24hpi, 2dpi, 3dpi, 5dpi, 7dpi) and one in culture reference (fungus grown on cellophane membranes overlaying potato dextrose agar). Analysis of this transcriptome identified five in planta gene expression clusters or waves corresponding to three specific infection stages: early, mid and mid-late infection of subcuticular biotrophic host-colonization. In our analysis we focus on general fungal nutrition (plant cell wall degrading enzymes and transporters) as well as effectors (proteinaceous effectors and secondary metabolites). Early infection was characterized by the expression of genes that encode plant cell wall-degrading enzymes (PCWDEs) and proteins associated with oxidative stress responses. Mid-late infection was characterized by genes that encode PCWDEs and effector candidates (ECs).
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:Granny Smith apples (Malus x domestica Borkh) grown in commercial orchards were harvested at physiological mature stage and maintained 6 months in cold storage with or without 1-MCP post-harvest treatment, and with or without enriched ozone atmosphere.
