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Garden asparagus ( Asparagus officinalis L.) is a popular vegetable cultivated worldwide. The secondary metabolites in its shoot are helpful for human health. We analyzed A . officinalis transcriptomes and identified differentially expressed genes (DEGs) involved in the biosynthesis of rutin and protodioscin, which are health-promoting functional compounds, and determined their association with stem color. We sequenced the complete mRNA transcriptome using the Illumina high-throughput sequencing platform in one white, three green, and one purple asparagus cultivars. A gene set was generated by de novo assembly of the transcriptome sequences and annotated using a BLASTx search. To investigate the relationship between the contents of rutin and protodioscin and their gene expression levels, rutin and protodioscin were analyzed using high-performance liquid chromatography. A secondary metabolite analysis using high-performance liquid chromatography showed that the rutin content was higher in green asparagus, while the protodioscin content was higher in white asparagus. We studied the genes associated with the biosynthesis of the rutin and protodioscin. The transcriptomes of the five cultivars generated 336 599 498 high-quality clean reads, which were assembled into 239 873 contigs with an average length of 694 bp, using the Trinity v2.4.0 program. The green and white asparagus cultivars showed 58 932 DEGs. A comparison of rutin and protodioscin biosynthesis genes revealed that 12 of the 57 genes associated with rutin and two of the 50 genes associated with protodioscin showed more than four-fold differences in expression. These DEGs might have caused a variation in the contents of these two metabolites between green and white asparagus. The present study is possibly the first to report transcriptomic gene sets in asparagus. The DEGs putatively involved in rutin and protodioscin biosynthesis might be useful for molecular engineering in asparagus.

In this study, we investigated changes in the isoflavone content, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS), and anti-inflammatory activities of small-seeded and large-seeded soybean cultivars during germination (light/dark conditions). Total isoflavone content was higher at the seed stage in largeseeded soybeans, while it increased after 7 days of germination in small-seeded soybeans, particularly in response to light conditions, under which they had high TPC, TFC, and antioxidant activities. In large-seeded soybeans, the germination environment did not significantly affect TFC or DPPH inhibition, whereas TPC and ABTS inhibition were high under dark germination conditions. Extracts of sprouts exhibited superior anti-inflammatory activities. Nitric oxide production was slightly lower in small-seeded and large-seeded soybeans germinated under light and dark conditions, respectively. Our findings indicate that germinated soybeans improved nutritionally, and that enhancement of bioactivity under different germination environments could contribute to the selection of appropriate soybean cultivars.

Lactuca indica L. has been traditionally used as a wild vegetable and as a medicinal plant for centuries. The various compounds present in it and their biological activities have been extensively reported. Hairy-root culture combined with agrobacterium-meditated metabolic engineering is a useful technique to achieve stable production of biologically active plant compounds. Here, we evaluated the enhancement of secondary metabolites in L. indica L. and their bioactivities by testing culture media composition and the use of an elicitor. Hairy roots were induced and cultured in MS or SH liquid media for 2 weeks prior to treatment with various concentrations of MeJa, for different periods. The resulting phenolic contents and physiological activities were analyzed. Higher total phenolic, flavonoid, and hydroxycinnamic acids contents were attained by elicitation with MeJa. Metabolite accumulation, especially in SH media and in the presence of MeJa, was time dependent. Particularly, accumulation of chicoric acid increased markedly with time. Similarly, we observed time dependent positive and negative responses of antioxidant activity in DPPH and ABTS assays, respectively. As in previous studies, the highest correlation was found between total phenolic content and total flavonoid content. Further, 3,5-DCQA showed the highest correlation with total phenolic content, total flavonoid content, and antioxidant activities in hydroxycinnamic acids. Our data effectively identified optimal culture conditions to increase the accumulation of secondary metabolites and antioxidant activity in hairy roots cultures of L. indica L.

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