Project description:Using sRNA-Seq to provide small RNA status in fruit ripening stages in sweet orange DNA methylation is an important epigenetic mark involved in many biological processes. The genome of the climacteric tomato fruit undergoes a global loss of DNA methylation due to active DNA demethylation during the ripening process. It is unclear whether the ripening of other fruits is also associated with global DNA demethylation. We characterized the single-base resolution DNA methylomes of sweet orange fruits. Compared to immature orange fruits, ripe orange fruits gained DNA methylation at over 30,000 genomic regions and lost DNA methylation at about 1,000 genomic regions, suggesting a global increase in DNA methylation during orange fruit ripening. This increase in DNA methylation was correlated with decreased expression of DNA demethylase genes. The application of a DNA methylation inhibitor interfered with ripening, indicating that the DNA hypermethylation is critical for the proper ripening of orange fruits. We found that ripening-associated DNA hypermethylation was associated with the repression of several hundred genes, such as photosynthesis genes, and with the activation of hundreds of genes including genes involved in ABA responses. Our results suggest important roles of DNA methylation in orange fruit ripening.
Project description:QN Orange scallop was interspecific hybrids with orange adductor muscles. Previous studies shown the accumulation of carotenoids was present in QN Orange scallops. In this study, analysis of miRNA expression profiles was performed to explore possibly regulatory patterns in carotenoid accumulation in adductor muscles of QN Orange scallops. Based on small RNA sequencing, a total of 3289 miRNAs and 91 differential expression miRNAs were identified between white and orange adductor muscles, respectively. GO and KEGG enrichment analysis of target genes of DE miRNA enriched in the transmembrane transporter activity-related pathways, kinase activity-related pathways, signal transduction-related pathways, ABC transporters, Retinol metabolism, lipid related metabolism and calcium signaling pathway.
Project description:In 1976, a spontaneous mutant derived from Poncirus trifoliata (L.) Raf with short juvenile phase, namely, precocious trifoliate orange, was found in Yichang, Hubei province, China. Compared with 6 to 8 years of the wild-type trifoliate orange, almost all of the seedlings germinated from precocious trifoliate orange only have 1 to 2 years’ juvenile period, and 20% seedlings even flowered in the year after germination. Therefore, precocious trifoliate orange is an ideal material for studying the role of miRNAs involved in citrus juvenile and adult developmental stages. To characterize these miRNAs expressed at the juvenile and adult development stages of citrus, Affymetrix miRNA arrays were used to generate miRNA profiles of shoot meristems of trifoliate orange, the results revealed that some miRNAs were down-regulated expressed at adult stage compared with juvenile stage. Detailed comparison of the expression patterns of miRNAs and corresponding target genes revealed the negative correlation between them, while few of them are positively correlated.