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:We performed Illumina sequencing of sRNA libraries prepared from juvenile and reproductive phase buds from the apple trees. A large number of sRNAs exemplified by 33 previously annotated miRNAs and 6 novel members displayed significant differential expression (DE) patterns in juvenile and reproductive stages. The study provides new insight into our understanding of fundamental mechanism of poorly studied phase transitions in apple and other woody plants and important resource for future in-depth research in the apple development.
Project description:miRNAs are key players in multiple biological processes, therefore analysis and characterization of these small regulatory RNAs is a critical step towards better understanding of animal and plant biology. In apple (Malus domestica) two hundred microRNAs are known, which most probably represents only a fraction of miRNAome diversity. As a result, more effort is required to better annotate miRNAs and their functions in this economically important species. We performed deep sequencing of twelve small RNA libraries obtained for fire blight resistant and fire blight sensitive trees. In the sequencing results we identified 116 novel microRNAs and confirmed a majority of previously reported apple miRNAs. We then experimentally verified selected candidates with RT-PCR and stem-loop qPCR and performed differential expression analysis. Finally, we identified and characterized putative targets of all known apple miRNAs. In this study we considerably expand the apple miRNAome by identifying and characterizing dozens of novel microRNAs. Moreover, our data suggests that apple microRNAs might be considered as regulators and markers of fire blight resistance.
Project description:Fire blight (FB) is a bacterial disease affecting plants from Rosaceae family, including apple and pear. FB develops after the infection of Erwinia amylovora, gram-negative enterobacterium, and results in burnt-like damages and wilting, which can affect all organs of the plant. Although the mechanisms underlying disease response in apples are not elucidated yet, it has been well described that FB resistance depends on the rootstock type. The main objective of this work was to identify miRNAs involved in response to bacterial infection in order to better explain apple defense mechanisms against fire blight disease. We performed deep sequencing of eighteen small RNA libraries obtained from inoculated and non-inoculated Gala apple leaves. 233 novel plant mature miRNAs were identified together with their targets and potential role in response to bacterial infection. We identify three apple miRNAs responding to inoculation (mdm-miR168a,b, mdm-miR194C and mdm-miR1392C) as well as miRNAs reacting to bacterial infection in a rootstock-specific manner (miR395 family). Our results provide insights into the mechanisms of fire blight resistance in apple.
Project description:Our data showed that lipid and glucose metabolic pathways genes were expressed at higher levels in gluteofemoral adipocyte fraction in pears, while genes associated with inflammation were higher in both abdominal and gluteofemoral apple adipocyte fraction. Gluteofemoral adipocyte chromatin from pear-shaped women contained a significantly higher number of differentially open ATAC-seq peaks relative to chromatin from the apple-shaped gluteofemoral adipocytes. In contrast, abdominal adipocyte chromatin openness showed few differences between apple and pear-shaped women. We revealed a correlation between gene transcription and open chromatin at the proximity of the TSS of some of the differentially expressed genes.