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Background Anthocyanins are plant secondary metabolites with key roles in attracting insect pollinators and protecting against biotic and abiotic stresses. They have potential health-promoting effects as part of the human diet. Anthocyanin biosynthesis has been elucidated in many species, enabling the development of anthocyanin-enriched fruits, vegetables, and grains; however, few studies have investigated Brassica napus anthocyanin biosynthesis. Results We developed a high-anthocyanin resynthesized B. napus line, Rs035, by crossing anthocyanin-rich B. rapa (A genome) and B. oleracea (C genome) lines, followed by chromosome doubling. We identified and characterized 73 and 58 anthocyanin biosynthesis genes in silico in the A and C genomes, respectively; these genes showed syntenic relationships with 41 genes in Arabidopsis thaliana and B. napus. Among the syntenic genes, twelve biosynthetic and six regulatory genes showed transgressively higher expression in Rs035, and eight structural genes and one regulatory gene showed additive expression. We identified three early-, four late-biosynthesis pathways, three transcriptional regulator genes, and one transporter as putative candidates enhancing anthocyanin accumulation in Rs035. Principal component analysis and Pearson’s correlation coefficients corroborated the contribution of these genes to anthocyanin accumulation. Conclusions Our study lays the foundation for producing high-anthocyanin B. napus cultivars. The resynthesized lines and the differentially expressed genes we have identified could be used to transfer the anthocyanin traits to other commercial rapeseed lines using molecular and conventional breeding. Electronic supplementary material The online version of this article (10.1186/s40709-018-0090-6) contains supplementary material, which is available to authorized users.

Pink-fruited tomato is characterized by transparent peel with lack of flavonoid NC (Naringenin Chalcone). SlMYB12 is a transcription regulator of NC biosynthesis and marked as candidate gene regulating pink color trait of tomato. Causative allelic variations have been reported previously in the SlMYB12 as 603-bp deletion in promoter region, two SNPs (− > A) and (C > T) in the second exon and (G > T) nucleotide substitution in the second intron. Here, we tested these variations in eighty-five pink inbred lines and two red lines. Among them fifty lines were homozygous for the 603-bp deletion and twenty-eight for the insertion (− > A). No variations were observed in pink lines (16NWS01, 16NWS24, 16NWS28, 16NWS29, 16NWS30, 16NWS34 and 16NWS82). Cloning and sequencing of SlMYB12 gene revealed two new SNPs G > A at 1794 bp and 1851 bp positions of genomic sequence in six lines. While 44.75 Kb deletion was identified proximate to SlMYB12 region in the line 16NWS82. These new variations together with previously reported markers could serve as valuable markers in pink tomato breeding.

Anthocyanins are the resultant end-point metabolites of phenylapropanoid/flavonoid (F/P) pathway which is regulated at transcriptional level via a series of structural genes. Identifying the key genes and their potential interactions can provide us with the clue for novel points of intervention for improvement of the trait in strawberry. We profiled the expressions of putative regulatory and biosynthetic genes of cultivated strawberry in three developmental and characteristically colored stages of fruits of contrastingly anthocyanin rich cultivars: Tokun, Maehyang and Soelhyang. Besides FaMYB10, a well-characterized positive regulator, FaMYB5, FabHLH3 and FabHLH3-delta might also act as potential positive regulators, while FaMYB11, FaMYB9, FabHLH33 and FaWD44-1 as potential negative regulators of anthocyanin biosynthesis in these high-anthocyanin cultivars. Among the early BGs, Fa4CL7, FaF3H, FaCHI1, FaCHI3, and FaCHS, and among the late BGs, FaDFR4-3, FaLDOX, and FaUFGT2 showed significantly higher expression in ripe fruits of high anthocyanin cultivars Maehyang and Soelhyang. Multivariate analysis revealed the association of these genes with total anthocyanins. Increasingly higher expressions of the key genes along the pathway indicates the progressive intensification of pathway flux leading to final higher accumulation of anthocyanins. Identification of these key genetic determinants of anthocyanin regulation and biosynthesis in Korean cultivars will be helpful in designing crop improvement programs.

The color of tomato (Solanum lycopersicum) fruit flesh is often used as an indicator of quality. Generally, fruit color is determined by the accumulation of carotenoids and flavonoids, along with concomitant degradation of chlorophylls during ripening. Several genes, such as phytoenesynthetase1 (Psy1), STAY-GREEN (SGR), and SlMYB12, have been extensively studied to elucidate the genes controlling fruit coloration. In this study, we observed low carotenoid levels without degradation of chlorophylls in green-fruited tomato caused by mutations in three genes, Psy1, SGR, and SlMYB12. We crossed two inbred lines, BUC30 (green-fruited) and KNR3 (red-fruited), to confirm the causal effects of these mutations on fruit coloration. The F2 population segregated for eight different fruit colors in the proportions expected for three pairs of gene, as confirmed by a chi-square test. Therefore, we developed a population of tomato with diverse fruit colors and used molecular markers to detect the genes responsible for the individual fruit colors. These newly-designed DNA-based markers can be used for selecting desired fruit color genotypes within adapted breeding materials and cultivars for breeding.

Erucic acid (22:1) is a valuable renewable resource for the oleochemical industry. Currently available high erucic acid rapeseed cultivars contain only about 50% erucic acid in the seed oil. A substantial increase of the erucic acid content of the rapeseed oil could increase market prospects. The transgenic line TNKAT, over expressing the rapeseed fatty acid elongase gene (fae1) and expressing the Ld-LPAAT gene from Limnanthes douglasii was crossed with the line 6575-1 HELP (high erucic and low polyunsaturated fatty acid). A from the F1 plants produced population of 90 doubled haploid (DH) lines was tested in a greenhouse with three replicates. Parental lines TNKAT and 6575-1 HELP contained 46 and 50% erucic acid in the seed oil, respectively. In the DH population the erucic acid content ranged between 35 and 59%. The Ld-LPAAT + Bn-fae1.1 transgene showed a 1:1 segregation. The transgenic DH lines contained up to 8% trierucolyglycerol, but surprisingly had a by 2.3% lower erucic acid content compared to the non-transgenic segregants. Results indicated that the ectopically expressed fae1.1 gene may not be functional. The DH population also showed a large quantitative variation for PUFA content ranging from 6 to 28% (TNKAT: 21%, 6575-1 HELP: 8%). Regression analysis showed that in the DH population a 10% reduction in PUFA content led to a 4.2% increase in erucic acid content. Development of locus specific PCR primers for the two resident erucic acid genes fae1.1 (A-genome) and fae1.2 genes (C-genome) of rapeseed allowed sequencing of the respective alleles from TNKAT and 6575-1 HELP. Single nucleotide polymorphisms were only found for the fae1.1 gene. Use of allele specific fae1.1 PCR primers, however, did not reveal a significant effect of the fae1.1 allele from either parent on erucic acid content. The high erucic acid low polyunsaturated fatty acid DH lines and the fae1 locus specific primers developed in the present study should be useful in future studies aimed at increasing erucic acid content in rapeseed. peerReviewed