Anthocyanins are important pigments and are responsible for red coloration in plums. However, little is known about the molecular mechanisms underlying anthocyanin accumulation in plum fruits. In this study, the RNA-seq technique was used to analyze the transcriptomic changes during fruit ripening in the red-fleshed plum (Prunus salicina Lindl.) cultivar ‘Furongli’. Over 161 million high-quality reads were assembled into 52,093 unigenes and 49.4% of these were annotated using public databases. Of these, 25,681 unigenes had significant hits to the sequences in the NCBI Nr database, 17,203 unigenes showed significant similarity to known proteins in the Swiss-Prot database and 5816 and 8585 unigenes had significant similarity to existing sequences in the Kyoto Encyclopedia of Genes and Genomes and the Cluster of Orthologous Groups databases, respectively. A total of 3548 unigenes were differentially expressed during fruit ripening and 119 of these were annotated as involved in “biosynthesis of other secondary metabolites.” Biological pathway analysis and gene ontology term enrichment analysis revealed that 13 differentially expressed genes are involved in anthocyanin biosynthesis. Furthermore, transcription factors such as MYB and bHLH, which may control anthocyanin biosynthesis, were identified through coexpression analysis of transcription factors, and structural genes. Real-time qPCR analysis of candidate genes showed good correlation with the transcriptome data. These results contribute to our understanding of the molecular mechanisms underlying anthocyanin biosynthesis in plum flesh. The transcriptomic data generated in this study provide a basis for further studies of fruit ripening in plum.

Dynamics in organic acid anions were not solely controlled by a single enzyme but regulated by the integrated activity of enzymes such as nicotinamide adenine dinucleotide phosphate-malic enzyme (NADP-ME), NAD-ME, PEPC, ACO and NADP-isocitrate dehydrogenase. Sugar metabolism enzymes such as PGI, invertase and HK may play vital roles in the regulation of individual sugar metabolic processes. © 2018 Society of Chemical Industry.

No abstract

Plum is one of the most important stone fruits in the world and anthocyanin-rich plums are increasingly popular due to their health-promoting potential. In this study, we investigated the mechanisms of anthocyanin accumulation in the flesh of the red-fleshed mutant of the yellow-fleshed plum ‘Sanyueli’. RNA-Seq and qRT-PCR showed that anthocyanin biosynthetic genes and the transcription factor PsMYB10.2 were upregulated in the flesh of the mutant. Functional testing in tobacco leaves indicated that PsMYB10.2 was an anthocyanin pathway activator and can activate the promoter of the anthocyanin biosynthetic genes PsUFGT and PsGST. The role of PsMYB10.2 in anthocyanin accumulation in the flesh of plum was further confirmed by virus-induced gene silencing. These results provide information for further elucidating the underlying mechanisms of anthocyanin accumulation in the flesh of plum and for the breeding of new red-fleshed plum cultivars.

Chinese plum (Prunus salicina Lindl.) is a stone fruit that belongs to the Prunus genus and plays an important role in the global production of plum. In this study, we report the genome sequence of the Chinese plum ‘Sanyueli’ (P. salicina Lindl.), which is known to have a low-chill requirement. The assembled genome size was 308.06 Mb, with a contig N50 of 815.7 kb. A total of 30,159 protein-coding genes was predicted from the genome and 56.42% (173.39 Mb) of the genome was annotated as repetitive sequence. Bud dormancy is influenced by chilling requirement in plum and partly controlled by DORMANCY ASSOCIATED MADS-box (DAM) genes. Six tandemly arrayed PsDAM genes were identified in the assembled genome. Sequence analysis of PsDAM6 in ‘Sanyueli’revealed the presence of large insertions in the intron and exon regions. Transcriptome analysis indicated that the expression of PsDAM6 in the dormant flower buds of ‘Sanyueli’ was significantly lower than that in the dormant flower buds of the high chill requiring ‘Furongli’ plum. In addition, the expression of PsDAM6 was repressed by chilling treatment. The genome sequence of ‘Sanyueli’ plum provides a valuable resource for elucidating the molecular mechanisms responsible for the regulation of chilling requirements, and it also useful for the identification of the genes involved in the control of other important agronomic traits and molecular breeding in plum.

No abstract

No abstract

Wufanshu (Vaccinium bracteatum Thunb.), which is a wild member of the genus Vaccinium, accumulates high concentration of anthocyanin in its berries. In this study, the accumulated anthocyanins and their derivatives in Wufanshu berries were identified through UHPLC–MS/MS analysis. Candidate anthocyanin biosynthetic genes were identified from the transcriptome of Wufanshu berries. qRT-PCR analyses showed that the expression of anthocyanin structural genes correlated with anthocyanin accumulation in berries. The R2R3-MYB, VbMYBA, which is a homolog of anthocyanin promoting R2R3-MYBs from other Vaccinium species, was also identified. Transient expression of VbMYBA in Nicotiana tabacum leaves confirmed its role as an anthocyanin regulator, and produced a higher anthocyanin concentration when compared with blueberry VcMYBA expression. Dual-luciferase assays further showed that VbMYBA can activate the DFR and UFGT promoters from other Vaccinium species. VbMYBA has an additional 23 aa at the N terminus compared with blueberry VcMYBA, but this was shown not to affect the ability to regulate anthocyanins. Taken together, our results provide important information on the molecular mechanisms responsible for the high anthocyanin content in Wufanshu berries.