Light conditions can cause quantitative and qualitative changes in anthocyanin. However, little is known about the underlying mechanism of light quality-regulated anthocyanin accumulation in fruits. In this study, light-emitting diodes (LEDs) were applied to explore the effect of red and blue light on strawberry coloration. The results showed contents of total anthocyanins (TA), pelargonidin 3-glucoside (Pg3G) and pelargonidin 3-malonylglucoside (Pg3MG) significantly increased after blue and red light treatment. Pg3G was the major anthocyanin component in strawberry fruits, accounting for more than 80% of TA, whereas Pg3MG accounted for a smaller proportion. Comparative transcriptome analysis was conducted using libraries from the treated strawberries. A total of 1402, 5034, and 3764 differentially-expressed genes (DEGs) were identified in three pairwise comparisons (red light versus white light, RL-VS-WL; blue light versus white light, BL-VS-WL; blue light versus red light, BL-VS-RL), respectively. Photoreceptors and light transduction components remained dynamic to up-regulate the expression of regulatory factors and structural genes related to anthocyanin biosynthesis under red and white light, whereas most genes had low expression levels that were not consistent with the highest total anthocyanin content under blue light. Therefore, the results indicated that light was an essential environmental factor for anthocyanin biosynthesis before the anthocyanin concentration reached saturation in strawberry fruits, and blue light could quickly stimulate the accumulation of anthocyanin in the fruit. In addition, red light might contribute to the synthesis of proanthocyanidins by inducing LAR and ANR.

The carotenoid isomerase gene (BoaCRTISO) of Chinese kale was targeted and edited using the CRISPR/Cas9 system in the present study. The results showed a high mutation rate (81.25%), and 13 crtiso mutants were obtained. Only two types of mutations, insertions and replacements, were found. Both the total and individual carotenoid and chlorophyll concentrations of the biallelic and homozygous mutants were reduced, and the total levels declined by 11.89–36.33%. The color of the biallelic and homozygous mutants changed from green to yellow, likely reflecting a reduction in the color-masking effect of chlorophyll on carotenoids. The expression levels of most carotenoid and chlorophyll biosynthesis-related genes, including CRTISO, were notably lower in the mutants than in the WT plants. In addition, the functional differences between members of this gene family were discussed. In summary, these findings indicate that CRISPR/Cas9 is a promising technique for the quality improvement of Chinese kale and other Brassica vegetables.

• Fructose and glucose were the predominant sugars in Chinese cherry fruits. • Malic acid was the most abundant organic acid in Chinese cherry fruits. • Increase in fructose and reduction in malic acid during domestication. • Rating criteria of flavor evaluation indicators was established.

Anthocyanins are water-soluble pigments in plants. They confer both economic and healthy profits for humans. To gain a deeper insight into the regulation of anthocyanin biosynthesis in octoploid strawberry (Fragaria×ananassa; Fa), a widely consumed economically important fruit, we performed comparative transcriptomic analysis of red- and white-fleshed strawberry cultivars in two ripening stages. In total, 365,455 non-redundant transcripts were assembled from the RNA sequencing (RNAseq) data. Of this collection, 377 were annotated as putative anthocyanin-related transcripts. Differential expression analysis revealed that 57 anthocyanin biosynthesis transcripts were down-regulated, and 89 transcription factors (TFs) were either down- or up-regulated under anthocyanin deficiency. Additionally, amongst the 50,601 putative long non-coding RNAs (lncRNAs) identified here, 68 lncRNAs were differentially expressed and co-expressed with differentially expressed anthocyanin-related mRNAs; 2,070 co-expressing lncRNA–mRNA pairs were generated. Expression profile analysis revealed that it was the limited expression of FaF3'H (flavonoid 3'-hydroxylase) that blocked the cyanidin 3-glucoside accumulation in the two investigated strawberry cultivars. This was further supported by a transient overexpression experiment with FaMYB10. The down-regulated lncRNAs might participate in anthocyanin regulation by acting as targets for microRNAs (miRNAs). The level of competitive intensity in miRNA and lncRNA for the same mRNA targets was probably lower in the white-fleshed strawberries, which can release the repression effect of the mRNAs in red-fleshed strawberry as a result. This study for the first time presents lncRNAs related to anthocyanins in strawberries, provides new insights into the anthocyanin regulatory network and also lays the foundation for identifying new anthocyanin regulators in strawberry.

Rubus L. is a large and taxonomically complex genus, species of which exhibit apomixis, polyploidy and frequent hybridization. Most of Chinese Rubus are assigned in two major sections, Idaeobatus and Malachobatus. To explore the phylogenetic relationships within Chinese Rubus, inferences upon three chloroplast DNA (rbcL, rpl20-rps12 and trnG-trnS), nuclear ribosomal ITS, and two low-copy nuclear markers (GBSSI-2 and PEPC) were deduced in 142 Rubus taxa from 17 subsections in 6 sections. nrITS and GBSSI-2 were the most informative among the six DNA regions assessed. Phylogenetic relationships within Rubus were well resolved by combined nuclear datasets rather than chloroplast markers. The phylogenetic inferences strongly supported that section Idaeobatus was a polyphyletic group with four distant clades. All samples of sect. Malachobatus formed a monophyletic clade, in which R. tsangorum and R. amphidasys of sect. Dalibardastrum, and R. peltatus from subsection Peltati of sect. Idaeobatus were always nested. Rubus pentagonus (2n = 2x = 14) from subsect. Alpestres of sect. Idaeobatus was a sister group to the polyploid sect. Malachobatus, as well as the polytomy of three sect. Cyalctis members. This suggests that some polyploids of Malachobatus might originate from common ancestors, via polyploidization of hybrids between R. pentagonus and sect. Cylactis species. They had experienced species explosion in a short time. Section Dalibardastrum species have potential parental lineages from subsects. Moluccani and Stipulosi of sect. Malachobatus. Based on molecular phylogenies, we also provided recommendations for the taxonomic treatments of four taxa. In addition, our results showed certain incongruence between chloroplast and nuclear markers, which might be due to hybridization and introgression.