Differential expression profiles of anthocyanidin biosynthesis gene during black rice seed development

The black rice (Oryza sativa cv. Heugjinju) is rich in anthocyanins which is beneficial to human health. To correlate the biosynthesis of the pigments with relevant genes, the mRNA level of genes involved in anthocyanin biosynthesis was monitored by quantitative real-time polymerase chain reaction (qRT-PCR) during seed development of black rice. The mRNA level of F3’H, DFR, and ANS, key enzymes in anthocyanidin biosynthesis, peaked at 10 days after flowering. In general, the absolute level of ANS was approximately one order higher than F3’H, F3’5’H, and DFR in 10 days after flowering. The transcript level of major seed protein gene GluA-3, taken as reference, was also at the highest on the 10 days after flowering. However, the level of CHS isogenes was highest at 15 or 20 days after flowering. The highest transcript level of the genes, except CHS, preceded the highest anthocyanidin content by 5 days. This pattern coincided with an increase of anthocyanin content between 10 and 15 days after flowering. From these findings, it is suggested that particular CHS isoforms might be responsible for the anthocyanin production in black rice

Expression analysis of diosgenin pathway genes and diosgenin accumulation in fenugreek sprouts after exposure to copper sulfate

Trigonella foenum-graecum L. is an annual herb belonging to the family Fabaceae commonly called Fenugreek. It is rich in various secondary metabolites such as alkaloids, flavonoids, phenolic compounds, and steroidal saponins. In recent years, diosgenin has much attention in the cosmetic, functional food, and pharmaceutical industries. In this study we aimed to examine the effect of different concentrations of copper sulfate (CuSO4) on growth, diosgenin biosynthetic (DB) gene expression, and diosgenin accumulation in T. foenum-graecum sprouts. Results showed that the seed germination, fresh weight, shoot length, and root length were gradually decreased with increasing the CuSO4 concentrations. In contrast, the expression level of DBGs i.e., TfSQS, TfSQLE, TfCAS, and TfSTRL were gradually upregulated with increasing the CuSO4 concentrations. Among all those tested concentrations, the expression levels of all those genes were significantly higher in 0.5 mM CuSO4 treated sprouts. The highest expression level was obtained in the TfCAS gene, which was 3.25-fold higher than the unexposed sprouts. The diosgenin content was significantly influenced in the CuSO4 exposed sprouts. The highest diosgenin content was achieved in the 5.0 mM followed by 1.0, 10.0, and 0.5 mM CuSO4 exposed concentrations, with a reduction of 41%, 39%, 36%, and 35%, respectively. From these results, it is shown that exposure of fenugreek sprout to CuSO4 is one of the suitable strategies to enhance the accumulation of diosgenin content

Analysis of carotenoid accumulation and expression of carotenoid biosynthesis genes in different organs of Chinese cabbage (Brassica rapa subsp. pekinensis)

The relationship between carotenoid accumulation and expression of carotenoid biosynthesis genes was investigated in the flowers, stems, young leaves, old leaves, and roots of Chinese cabbage (Brassica rapa subsp. pekinensis). Quantitative real-time PCR analysis showed that the mRNA levels of BrPSY, BrPDS, BrZDS, BrLCYB, BrLCYE, BrCHXB, and BrZEP leading to the production of carotenoids were highest in the flowers or the leaves and lowest in the roots of Chinese cabbage. In contrast, the mRNA expression of BrNCED, a gene involved in abscisic acid (ABA) biosynthesis, was highest in the roots. High-performance liquid chromatography revealed that carotenoids, namely, lutein and β-carotene, were distributed predominantly in the flowers and leaves, with very little in the underground organ, the roots. Specifically, old leaves contained 120.3 μg/g lutein and 103.93 μg/g β-carotene, which is the most potent dietary precursor of vitamin A. Moreover, we found a relatively large amount of cis isomers of β-carotene, namely, 9-cis β-carotene and 13-cis β-carotene, in Chinese cabbage. These results provide insight into carotenoid biosynthetic mechanisms in Chinese cabbage and may be helpful in the metabolic engineering of carotenoid biosynthesis in plants

Molecular characterization of carotenoid biosynthetic genes and carotenoid accumulation in Scutellaria baicalensis Georgi

Scutellaria baicalensis has a wide range of biological activities and has been considered as an important traditional drug in Asia and North America for centuries. A partial-length cDNA clone encoding phytoene synthase (SbPSY) and full-length cDNA clones encoding phytoene desaturase (SbPDS), ξ-carotene desaturase (SbZDS), β-ring carotene hydroxylase (SbCHXB), and zeaxanthin epoxidase (SbZEP) were identified in S. baicalensis. Sequence analyses revealed that these proteins share high identity and conserved domains with their orthologous genes. SbPSY, SbPDS, SbZDS, SbCHXB, and SbZEP were constitutively expressed in the roots, stems, leaves, and flowers of S. baicalensis. SbPSY, SbPDS, and SbZDS were highly expressed in the stems, leaves, and flowers and showed low expression in the roots, where only trace amounts of carotenoids were detected. SbCHXB and SbZEP transcripts were expressed at relatively high levels in the roots, stems, and flowers and were expressed at low levels in the leaves, where carotenoids were mostly distributed. The predominant carotenoids in S. baicalensis were lutein and β-carotene, with abundant amounts found in the leaves (517.19 and 228.37 μg g-1 dry weight, respectively). Our study on the biosynthesis of carotenoids in S. baicalensis will provide basic data for elucidating the contribution of carotenoids to the considerable medicinal properties of S. baicalensis

Why a universal Child Grant makes sense in Nepal: a four-step analysis

Whether cash transfers should be poverty targeted or universal within certain social categories remains a hotly debated topic. Recent plans to expand Nepal’s Child Grant programme brought this question sharply into focus. Using available secondary data, this article presents a four-step analysis that examines the costs and benefits of different approaches. Given the country’s poverty profile, the theoretical results of different targeting models, government capacity and overall costs, a universal (age-cohort targeted) approach achieves the best outcomes for childre

Phenylalanine ammonia-lyase expression and pyranocoumarin accumulation in Angelica gigas plantlets exposed to light-emitting diodes

Angelica gigas (Dang Gui) is an important medicinal plant. In this study, we examined the accumulation of pyranocoumarin (decursin and decursinol angelate) and the expression of phenylalanine ammonia-lyase (PAL) in Korean angelica plantlet grown under different light-emitting diodes (LEDs) (red, orange, green, blue, and white). Three weeks after LED exposure (WAE), the transcript levels of phenylalanine ammonia-lyase mRNA in seedlings grown under orange LEDs were 4-, 18-, and 7-fold higher than those in seedlings grown under green, blue, and white LEDs, respectively. The decursinol angelate content was almost double than the decursin content. The highest levels of decursin (3.2 mg/g dry weight) and decursinol angelate (6 mg/g dry weight) were detected in plants grown under orange LEDs, at 2 WAE. Therefore, we suggest that orange LEDs may affect decursin and decursinol angelate accumulation. The findings of this study could help to determine an effective strategy for producing secondary metabolites in A. gigas using LED technology

Cloning and Characterization of a Flavonol Synthase Gene from Scutellaria baicalensis

Flavonols are the most abundant of all the flavonoids and play pivotal roles in a variety of plants. We isolated a cDNA clone encoding flavonol synthase from Scutellaria baicalensis (SbFLS). The SbFLS cDNA is 1011 bp long, encodes 336 amino acid residues, and belongs to a family of 2-oxoglutarate-dependent dioxygenases. The overall structure of SbFLS is very similar to that of Arabidopsis thaliana anthocyanidin synthase (AtANS), with a β jelly-roll fold surrounded by tens of short and long α-helices. SbFLS was constitutively expressed in the roots, stems, leaves, and flowers, with particularly high expression in the roots and flowers. SbFLS transcript levels in the roots were 376-, 70-, and 2.5-fold higher than in the leaves, stems, and flowers. The myricetin content was significantly higher than that of kaempferol and quercetin. Therefore, we suggest that SbFLS mediates flavonol formation in the different organs of S. baicalensis. Our study may contribute to the knowledge of the role of FLS in S. baicalensis