Project description:The effect of site, cold storage, and scion genotype on the apple root microbiome and its effect on apple canker (Neonectria ditissima) severity
Project description:The purpose of this project is to examine the effects of rootstocks on the gene expression patterns in scions of apple trees. Gene expression patterns were examined in the Gala variety grafted onto seven different, commonly used rootstocks. These trees were grown in the greenhouse to limit environmental effects. Also, gene expression profiles were examined in three different varieties (Ambrosia, Melrose,and Gala) grafted onto B.9 rootstocks grown in the field. Keywords: apple, rootstock, graft, scion
Project description:miRNAs were important regulators involving in plant-pathogen interactions. However, their roles in apple response to Valsa canker pathogen (Valsa mali, Vm) infection were poorly understood. In this study, we constructed two miRNA libraries using the bark tissues of apple twig (Malus domestica Borkh “Fuji”) inoculated with Vm (IVm) and PDA medium (control, BMd). Among the all miRNAs, 23 miRNAs were specifically isolated in BMd and 39 miRNAs were specifically isolated in IVm. Compared with BMd, the expression of 294 miRNAs decreased, and 172 miRNAs increased in IVm, respectively. We also identified the target genes of these miRNAs using degradome sequencing technology. In total, 353 differentially expressed miRNAs during the pathogen infection were detected to target 1 077 unigenes with 2 251 cleavage sites. Based on GO and KEGG analysis, the genes were found to be mainly related to transcription regulation and signal transduction. We further selected 17 miRNAs and 22 corresponding target genes to detect the expression profiles during pathogen infection. The results indicate that most of them are involved in apple twig-Vm interaction. What’s more, miRNAs and their corresponding target genes seem to regulate the apple twig-Vm interaction by forming many complicated regulation networks. It is worth that a conserved miRNAs mdm-miR482b, which was down regulated in IVm compared with BMd, has 14 potential target genes, and most of them were disease resistance related genes. More important, the feedback regulation of sRNA pathway in apple twig was much more complex and critical in the interaction between apple bark tissue and V. mali. The results provide insights into the crucial functions of miRNAs in the woody plant, apple tree-Vm interaction.
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.
