Rutin Accumulation Research Articles

Rutin distribution in Tartary buckwheat: Identifying prime dietary sources through comparative analysis of post-processing treatments

Rutin is a crucial bioactive compound that determines the nutritional value of Tartary buckwheat (TB). However, the potential of utilizing TB as a dietary source of rutin for human consumption remains largely unexplored. This study aims to address these knowledge gaps by conducting a detailed analysis of rutin content distribution in TB tissues. Our findings revealed a significant variation in rutin content across different plant tissues. Notably, higher levels of rutin were found in embryos and cotyledons compared to other tissues, highlighting them as the primary sites of rutin accumulation in TB seeds and sprouts. Additional research on the processing of TB showed that sprouts and seeds retain high rutin levels even after boiling, steaming, deep-frying, stir-frying, and popping. Comparative analysis of different TB-derived products confirmed that cooked seeds and sprouts can serve as significant dietary sources of rutin. This study offers a foundational framework for the development of future dietary recommendations and applications of TB.

In Vitro: The Extraordinary Enhancement in Rutin Accumulation and Antioxidant Activity in Philodendron "Imperial Red" Plantlets Using Ti-Mo-Ni-O Nanotubes as a Novel Elicitor.

Rutin, a flavonoid phytochemical compound, plays a vital role in human health. It is used in treating capillary fragility and has anti-Alzheimer, anti-inflammatory, and antioxidant effects. In this study, Ti-Mo-Ni-O nanotubes (NTs) were used, for the first time, in an unprecedented plant biotechnology application, wherein in vitro Philodendron shoots (Philodendron erubescens) known as "Imperial Red" were targeted for rutin accumulation. The antioxidant responses and the accumulation of rutin were evaluated in treated Philodendron erubescens (P. erubescens) shoots using 5.0 mg/L of Ti-Mo-Ni-O NTs. The total phenolic content and total flavonoid content were estimated, and an ABTS+ assay, FRAP assay, and iron metal chelation assay were performed. The application of Ti-Mo-Ni-O NTs enhanced the rutin content considerably from 0.02 mg/g to 2.96 mg/g for dry-weight shootlet extracts. Therefore, the use of Ti-Mo-Ni-O NTs is proposed to be a superior alternative to elevate the rutin content. The aim of the current study is to target P. erubescens shoots grown in vitro for the accumulation of rutin compounds using Ti-Mo-Ni-O NT powder, to determine the quantitative and qualitative accumulation of rutin via HPLC-DAD analysis, and to estimate the antioxidant activity of P. erubescens shoot extract. This study presents a novel methodology for utilizing nano-biotechnology in the synthesis of plant secondary metabolites.

Enhancing rutin accumulation in Tartary buckwheat through a novel flavonoid transporter protein FtABCC2

Tartary buckwheat (Fagopyrum tataricum) is an annual coarse cereal from the Polygonaceae family, known for its high content of flavonoid compounds, particularly rutin. But so far, the mechanisms of the flavonoid transport and storage in Tartary buckwheat (TB) remain largely unexplored. This study focuses on ATP-binding cassette transporters subfamily C (ABCC) members, which are crucial for the biosynthesis and transport of flavonoids in plants. The evolutionary and expression pattern analyses of the ABCC genes in TB identified an ABCC protein gene, FtABCC2, that is highly correlated with rutin synthesis. Subcellular localization analysis revealed that FtABCC2 protein is specifically localized to the vacuole membrane. Heterologous expression of FtABCC2 in Saccharomyces cerevisiae confirmed that its transport ability of flavonoid glycosides such as rutin and isoquercetin, but not the aglycones such as quercetin and dihydroquercetin. Overexpression of FtABCC2 in TB hairy root lines resulted in a significant increase in total flavonoid and rutin content (P < 0.01). Analysis of the FtABCC2 promoter revealed potential cis-acting elements responsive to hormones, cold stress, mechanical injury and light stress. Overall, this study demonstrates that FtABCC2 can efficiently facilitate the transport of rutin into vacuoles, thereby enhancing flavonoids accumulation. These findings suggest that FtABCC2 is a promising candidate for molecular-assisted breeding aimed at developing high-flavonoid TB varieties.

Systematic analysis of the UDP-glucosyltransferase family: discovery of a member involved in rutin biosynthesis in Solanum melongena.

Eggplant (Solanum melongena) is an economically important crop and rich in various nutrients, among which rutin that has positive effects on human health is found in eggplant. Glycosylation mediated by UDP-glycosyltransferases (UGTs) is a key step in rutin biosynthesis. However, the UGT gene has not been reported in eggplant to date. Herein, 195 putative UGT genes were identified in eggplant by genome-wide analysis, and they were divided into 17 subgroups (Group A-P and Group R) according to the phylogenetic evolutionary tree. The members of Groups A, B, D, E and L were related to flavonol biosynthesis, and rutin was the typical flavonol. The expression profile showed that the transcriptional levels of SmUGT genes in Clusters 7-10 were closely related to those of rutin biosynthetic pathway genes. Notably, SmUGT89B2 was classified into Cluster 7 and Group B; its expression was consistent with rutin accumulation in different tissues and different leaf stages of eggplant. SmUGT89B2 was located in the nucleus and cell membrane. Virus-induced gene silencing (VIGS) and transient overexpression assays showed that SmUGT89B2 can promote rutin accumulation in eggplant. These findings provide new insights into the UGT genes in eggplant, indicating that SmUGT89B2 is likely to encode the final enzyme in rutin biosynthesis.

Plant immune inducer ZNC promotes rutin accumulation and enhances resistance to Botrytis cinerea in tomato

Gray mold is a destructive disease caused by Botrytis cinerea, a pervasive plant pathogen, which poses a threat to both tomato growth and postharvest storage. The utilization of induced resistance presents a potential strategy for combating plant pathogenic attacks. ZNC (zhinengcong), an extract derived from the endophytic fungus Paecilomyces variotii, has been discovered to play a vital role in preventing diverse forms of bacterial infections. Nevertheless, the precise mechanism behind its ability to enhance tomato resistance to fungi remains unclear. In this study, we found that the exogenous spraying of ZNC could significantly improve the resistance of tomato plants to B. cinerea. The results of both the metabolomic analysis and high-performance liquid chromatography (HPLC) demonstrated that tomato plants responded to ZNC treatment by accumulating high levels of rutin. Additional transcriptome analysis uncovered that rutin enhances tomato resistance possible by initiating the generation of reactive oxygen species (ROS) and phosphorylation of mitogen-activated protein kinases (MPKs) related genes expression during the initial phase of invasion by B. cinerea. In addition, we also found that rutin might activate plant immunity by eliciting ethylene (ET) and jasmonic acid (JA)-mediated pathways. Therefore, plant immune inducer ZNC and rutin has bright application prospects and high utilization value to control gray mold.Graphical

The effect of plant growth regulators on the antioxidant enzyme activity and secondary metabolite production in the cell suspension cultures of Melia azedarach L.

ABSTRACT In the present study, we investigated the effect of plant growth regulators and explant type on callus induction, cell suspension culture growth, antioxidant enzyme activity, and accumulation of rutin, quercetin, and kaempferol in M. azedarach L. cell cultures. Our studies showed that the inflorescence and petiole explants had a high percentage of callus induction compared to the leaf explants, whereas the highest callus growth was obtained from the leaf explants cultured on the MS medium containing 5 mg l−1 NAA and 5 mg l−1 BAP and 5 mg l−1 NAA and 3 mg l−1 kinetin Kin. Furthermore, the highest cell growth was obtained from the leaf and inflorescence calli transferred to liquid MS medium supplemented with 1 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D)+1 mg l−1 Kin/BAP. The highest activity of antioxidant enzymes and the lowest protein content was related to the leaf cell suspension cultures in liquid MS medium containing 3 mg l−1 NAA and 3 mg l−1 BAP. The inflorescence cell suspension cultures in the MS medium containing 3 mg l−1 NAA+1 mg l−1 BAP exhibited the highest rutin accumulation (47.536 mg g−1 FW). However, the highest amount of quercetin (8.570 mg g−1 FW) and kaempferol (5.420 mg g−1 FW) accumulation were obtained from the petiole cell suspension cultures in the MS medium with 1 mg l−1 2,4-D +1 mg l−1 Kin.

ГРЕЧИХА ПОСЕВНАЯ (Fagopirum esculentum) КАК ИСТОЧНИК РУТИНА НА СЕВЕРЕ КАЗАХСТАНА

The article presents the results of studies of buckwheat (Fagopyrum esculentum Moench) plants as a source of bioflavonoids – biologically active compounds of polyfunctional action. Buckwheat is the only agricultural crop in Kazakhstan that contains rutin. Modern pharmacological studies show that rutin helps lower blood cholesterol levels, exhibits high antioxidant activity and is used in the treatment of many chronic diseases. In the process of research, the gene resources of buckwheat (varieties, hybrids, populations) were studied and the content of rutin in the aerial parts of plants was determined. The dynamics of rutin accumulation in buckwheat plants was revealed, the presence of a relationship between the content of rutin and the main breeding and economic traits was established. A promising source material with a high content of rutin has been isolated for use in the breeding process. For the first time, the quantitative parameters of the content of rutin at various stages of the ontogenesis of buckwheat in the conditions of northern Kazakhstan were determined. The phases of plant development with the maximum concentration of rutin have been established. The initial material of buckwheat with a high content of rutin was evaluated for a complex of useful features. The variability of the color of the plant and grain (nucleus) as a marker for the selection of plants with a high content of rutin was studied. As a result of the research, the possibility of using the entire vegetative mass of buckwheat (flowers, leaves, stem) of various biotypes as a raw material for the production of rutin with the extraction of the target product has been shown.

Effects of light quality, photoperiod, CO2 concentration, and air temperature on chlorogenic acid and rutin accumulation in young lettuce plants

Environmental stimuli modulate plant metabolite accumulation, facilitating adaptation to stressful conditions. In this study, the effects of blue and red light, photoperiod, CO2 concentration, and air temperature on the chlorogenic acid (CGA) and rutin contents of lettuce (Lactuca sativa L.) were evaluated. Under continuous blue light and a high CO2 concentration (1000 ppm), the CGA level increased. The increased expression of phenylalanine ammonia-lyase (PAL) and activity of its product were correlated with high expression of cinnamate 4-hydroxylase (C4H) and coumarate 3-hydroxylase (C3H). Furthermore, changes in PAL activity altered the CGA content in lettuce exposed to the three environmental factors, blue light, continuous lighting and high CO2 concentration. In addition, the expression levels of genes related to flavonoid biosynthesis increased in accordance with the promotion of CGA accumulation by the environmental factors. Under continuous blue light, 400 ppm CO2 promoted rutin accumulation to a greater degree compared to 1000 ppm CO2, by downregulating DFR expression. Low air temperature induced CGA accumulation in lettuce grown under continuous blue light and 1000 ppm CO2. Therefore, light quality, photoperiod, CO2 concentration, and air temperature exert synergistic effects on the CGA and rutin contents of lettuce by modulating activity in the corresponding biosynthesis pathways.

Polyamine Elicitation of Quercetin and Rutin Production in Callus Cultures of Caper and Impact to Regeneration

Nowadays, efforts to produce high amounts of secondary metabolites with anticancer properties in plants have become remarkable studies of biotechnological approaches. Polyamines are known to have successful roles in plant metabolism and molecular signalling. The important point is to determine the type and concentration of polyamine suitable for the physiology of the plant. This study was carried out to examine the effects of different polyamine applications in callus culture of Caper (Capparis L.) plant on plant regeneration and the production of quercetin and rutin with anticancer properties. For this purpose, different varieties (spermine, spermidine, and putrescine) and concentrations (0.0, 0.5, and 1.0 mg/l) of polyamines and 2.0 mg/l 6-benzylaminopurine (BAP) and 1.0 mg/l α-naphthaleneacetic acid (NAA) of plant growth regulators were added to the Murashige and Skoog (MS) culture medium. According to the results, the highest value in terms of callus induction was determined in 1.0 mg/l spermine, the highest value in plant regeneration was obtained in 0.5 mg/l spermine, and the highest quercetin and rutin accumulation were detected in 0.5 mg/l spermidine application. The regeneration and the amount of quercetin increased approximately 2-fold compared to the control group in the aforementioned polyamine (PA) applications. Our findings showed that spermine and spermidine proved more effective in the callus culture of Caper than putrescine, and the use of low-dose polyamines gave outstanding results. Therefore a particularly valuable finding obtained in this study is that polyamines can be used as an effective elicitor in the tissue culture of Caper plant.

Study of the Effect of Selective Media with High Doses of Zinc on Regeneration Ability and Rutin Accumulation in Common Buckwheat In Vitro

Biotechnological methods are widely used in modern common buckwheat (Fagopyrum esculentum Moench) studies, constitute an effective tool to create the best agronomic traits of the crop, and can also be used to breed forms, resistant to heavy metal ion toxicity, which is important in the environment of constantly growing anthropogenic pressure on ecosystems. The studied high concentrations of zinc salts (808–1313 mg L−1) in the nutrient medium in vitro had an inhibitory effect on buckwheat, which was manifested by a decrease in values of its morphological indicators. Ion stress had an adverse effect on 7–9% of plants from their total number, indicating high plasticity and resistance of F. esculentum to highly toxic doses of zinc. The stress state of F. esculentum significantly increases the production of flavonoid compounds, including rutin, in plant cells, which is used in biotechnology to assess and obtain buckwheat forms of high flavonoid induction capacity. The processes of rutin biosynthesis were most intense in test-tube plants of the Izumrud × Inzerskaya hybrid obtained after exposure to high doses of zinc 1010–1212 mg L−1. F. esculentum genotypes obtained using selective backgrounds with high zinc concentrations are promising biosystems for synthesis of rutin, valuable for pharmacology and medicine.

FtMYB6, a Light-Induced SG7 R2R3-MYB Transcription Factor, Promotes Flavonol Biosynthesis in Tartary Buckwheat (Fagopyrum tataricum).

Tartary buckwheat (Fagopyrum tataricum) is rich in flavonols, which are thought to be highly beneficial for human health. However, little is known about the regulatory mechanism of flavonol biosynthesis in Tartary buckwheat. In this study, we identified and characterized a novel SG7 R2R3-MYB transcription factor in Tartary buckwheat, FtMYB6. We showed that FtMYB6 is located in the nucleus and acts as a transcriptional activator. The FtMYB6 promoter showed strong spatiotemporal specificity and was induced by light. The expression of FtMYB6 showed a significant correlation with rutin accumulation in the roots, stems, leaves, and flowers. Overexpression of FtMYB6 in transgenic Tartary buckwheat hairy roots and tobacco (Nicotiana tabacum) plants significantly increased the accumulation of flavonols. In transient luciferase (LUC) activity assay, FtMYB6 promoted the activity of FtF3H and FtFLS1 promoters and inhibited the activity of the Ft4CL promoter. Collectively, our results suggest that FtMYB6 promotes flavonol biosynthesis by activating FtF3H and FtFLS1 expression.

Identification and tissue-specific expression of rutin biosynthetic pathway genes in Capparis spinosa elicited with salicylic acid and methyl jasmonate

Capparis spinosa is an edible medicinal plant which is considered as an excellent source of rutin. Rutin is a glycoside of the flavonoid quercetin that has been reported to have a beneficial role in controlling various diseases such as hypertension, arteriosclerosis, diabetes, and obesity. In this study, the partial cDNA of four genes involved in the rutin biosynthetic pathway including 4-coumaroyl CoA ligase (4CL), flavonoid 3′-hydroxylase (F3′H), flavonol synthase (FLS) and flavonol-3-O-glucoside L-rhamnosyltransferase (RT) were identified in C.spinosa plants for the first time. The protein sequences of these genes shared high similarity with the same proteins in other plant species. Subsequently, the expression patterns of these genes as well as rutin accumulation in C.spinosa leaves treated with different concentrations of salicylic acid (SA) and methyl jasmonate (MeJA) and also in different tissues of Caper plants treated with 100 mgL−1 SA and 150 μM MeJA were evaluated. The expression of all four genes was clearly up-regulated and rutin contents increased in response to MeJA and SA treatments after 24 h. The highest rutin contents (5.30 mgg−1 DW and 13.27 mgg−1 DW), as well as the highest expression levels of all four genes, were obtained using 100 mgL−1 SA and 150 μM MeJA, respectively. Among the different tissues, the highest rutin content was observed in young leaves treated with 150 μM MeJA, which corresponded to the expression of related genes, especially RT, as a key gene in the rutin biosynthetic pathway. These results suggest that rutin content in various tissues of C. spinosa can be enhanced to a significant extent by MeJA and SA treatments and the gene expression patterns of rutin-biosynthesis-related genes are regulated by these elicitors.

Yield and quality performances of organic tomato as affected by genotype and industrial processing in southern Italy

Identifying new tomato (Solanum lycopersicum L.) genotypes with improved technological performances is an important requisite for achieving high yield and quality of industrial produce. An open-field experiment was carried out in southern Italy in order to assess the effects of three elongated tomato hybrids oriented to ‘peeled’ chain (Max 14802, Massaro, Taylor) in terms of crop productivity and nutritional value. The hybrid Taylor showed the highest marketable yield due to the highest fruit number, whereas Massaro showed the highest processing efficiency. Among the three genotypes compared, titratable acidity and fiber were highest in Max 14802 fruits (0.45 g anhydrous citric acid·100 g-1 and 0.94 g·100 g-1 respectively), Taylor was best ranking in terms of fat and sucrose content, and Massaro achieved the highest glucose, fructose and rutin accumulation. Compared to fresh fruits, peeled tomatoes attained higher values of total and soluble solids, reducing sugars, total polyphenols (referred to fresh weight), rutin and naringenin, but had a decreased value of colour coordinate a/b ratio. No significant differences between the three tomato cultivars were recorded in terms of sensorial traits. From the present research interesting clues have arisen regarding the best performances of the hybrid Taylor in terms of fruit yield and organic acid content, and of the hybrid Massaro regarding the processing efficiency and fruit health-beneficial properties.

Trellis systems, rootstocks and season influence on the phenolic composition of ‘Chenin Blanc’ grape

ABSTRACT: The biosynthesis of phenolic compounds might be influenced by environmental factors, such as solar radiation, temperature and relative air humidity, and production system. Some components of the production system, particularly the trellis system and rootstock, might change the phenolic composition of grapes due to microclimate of the cultivation region. In this study, the phenolic profile of ‘Chenin Blanc’ grapes was characterized with different trellis systems and rootstocks in two consecutive production cycles by using high-performance liquid chromatography under tropical semi-arid conditions. In the second production cycle (Jan-May/2016), accumulation of (-) - epicatechin gallate and (-) - epigallocatechin gallate was higher when vigorous rootstocks were trellised to the lyre system, whereas the lyre system associated to rootstock ‘SO4’ resulted in higher rutin accumulation in the same cycle. There was little influence of the factors studied on trans-resveratrol and piceatannol accumulation. However, a higher accumulation of piceatannol was observed in the second productive cycle compared to cis-resveratrol and trans-resveratrol. This study highlights that accumulation of phenolic compounds is influenced not only by environmental factors typical of the production year season, but also by the trellis system and rootstock adopted. The identification of phenolic compounds in the accumulation stimulated by the combination of trellis system, rootstock, and production season allows to differentiate grape quality and add value to products derived from such combination in a tropical semi-arid region.

Rutin accumulation in gardenia calli cultures as a response to phenyl alanine and salicylic acid

BackgroundRutin is one of the flavonoid compounds found in different plant species. Rutin has powerful antioxidant properties. The main target of this study is to elevate rutin content in gardenia (Gardenia jasmonides Ellis) calli cultures. Different concentrations of phenyl alanine (2, 3, 4, and 5 mg/l) were used as a precursor for enhancement of rutin accumulation. Moreover, and to elevate rutin content, salicylic acid (SA) was used at different concentrations (34.5, 69, 103.5, and 138 mg/l). Various biochemical analyses, i.e., determination of total phenols, total flavonoids, and antioxidant activity during three periods, after 2 weeks (the first harvest), after 4 weeks (the second harvest), and after 5 weeks (the third harvest) of culture, were performed. In addition, determination of phenols and flavonoids content by high-performance liquid chromatography (HPLC) were estimated of the three periods.ResultsThe results showed that the highest value of total phenols (9.53 ± 0.55 mg GAE/g DW of callus) was recorded with 5 mg/l phenylalanine (PA) at the third harvest. While the highest value of total flavonoids (0.358 ± 0.002 mg QE/g DW of callus) was achieved using 2 mg/l P.A. at the third harvest. By using HPLC, it was found that the maximum rutin content was recorded with 3 mg/l PA at the third harvest (429 μg/g DW).ConclusionThis study showed that rutin and cinnamic acids were the major compounds detected with all treatments and during the three harvest phases of gardenia calli cultures. As well as results declared that the decreasing of cinnamic acid was correlated with the increasing of rutin content, and the maximum rutin content was recorded with applying of 3 mg/l PA at the third harvest (429 μg/g DW).

NtMYB4 and NtCHS1 Are Critical Factors in the Regulation of Flavonoid Biosynthesis and Are Involved in Salinity Responsiveness.

High levels of salinity induce serious oxidative damage in plants. Flavonoids, as antioxidants, have important roles in reactive oxygen species (ROS) scavenging. In the present study, the tobacco R2R3 MYB type repressor, NtMYB4, was isolated and characterized. The expression of NtMYB4 was suppressed by salinity. Overexpression of NtMYB4 reduced the salt tolerance in transgenic tobacco plants. NtMYB4 repressed the promoter activity of NtCHS1 and negatively regulated its expression. Rutin accumulation was significantly decreased in NtMYB4 overexpressing transgenic plants and NtCHS1 RNAi silenced transgenic plants. Moreover, high H2O2 and contents were detected in both types of rutin-reduced transgenic plants under high salt stress. In addition, exogenous rutin supplementation effectively scavenged ROS (H2O2 and ) and improved the salt tolerance of the rutin-reduced transgenic plants. In contrast, NtCHS1 overexpressing plants had increased rutin accumulation, lower H2O2 and contents, and higher tolerance to salinity. These results suggested that tobacco NtMYB4 acts as a salinity response repressor and negatively regulates NtCHS1 expression, which results in the reduced flavonoid accumulation and weakened ROS-scavenging ability under salt stress.

Assessment of variability in secondary metabolites and expected response to genotype selection in fenugreek (Trigonella spp.)

A better understanding of metabolites assists breeding industrial-friendly medicinal plants. The main objectives of the present study were to compare and screen several fenugreek accessions and estimate genetic variability with respect to phenolic and non-pheneolic metabolites. The leaf extracts of accessions in field experiment being established in two growing seasons (2014-15, 2015-16) were subjected to high- performance liquid chromatography (HPLC). No one accession was found to have high levels of all metabolite compounds but several accessions accumulated more than one metabolite at high level. T.f.g[H-37527] had the highest catechin (65.33 mg L−1) and rutin (26.46 mg L−1) whereas p-coumaric acid was not identified in several accessions. Catechin (36%), trans-ferulic acid (15%) and hesperetin (13%) with the highest share in the total metabolite content were the predominant compounds identified. Coumarin with the highest genotypic variation (GCV = 128.05%) was identified at 280 nm, whereas hesperetin which was identified at the same wavelength had the lowest GCV (39.97%). All metabolites were identified at 280 nm wavelength except chlorogenic acid which was identified at 320 nm. Estimation of response to selection (RS) showed that catechin (RS = 35.87%) was more responsive to selection whereas quercetin (RS = 3.82%) was relatively less responsive. Assessment of interrelationships between metabolites demonstrated the strong association of catechin, trans-ferulic acid and rutin accumulation in accessions tested. Overall, knowledge of genetic variation identified for metabolites tested significantly contributes to designing intra-specific crosses with potential interest to metabolite breeding programs and creates a solid basis for genotype selection aimed at better food quality, higher pharmaceutical uses and further improvement of fenugreek.

Transcriptome analysis of filling stage seeds among three buckwheat species with emphasis on rutin accumulation.

Buckwheat is an important minor crop with pharmaceutical functions due to rutin enrichment in the seed. Seeds of common buckwheat cultivars (Fagopyrum esculentum, Fes) usually have much lower rutin content than tartary buckwheat (F. tartaricum, Ft). We previously found a wild species of common buckwheat (F. esculentum ssp. ancestrale, Fea), with seeds that are high in rutin, similar to Ft. In the present study, we investigated the mechanism by which rutin production varies among different buckwheat cultivars, Fea, a Ft variety (Xide) and a Fes variety (No.2 Pingqiao) using RNA sequencing of filling stage seeds. Sequencing data generated approximately 43.78-Gb of clean bases, all these data were pooled together and assembled 180,568 transcripts, and 109,952 unigenes. We established seed gene expression profiles of each buckwheat sample and assessed genes involved in flavonoid biosynthesis, storage proteins production, CYP450 family, starch and sucrose metabolism, and transcription factors. Differentially expressed genes between Fea and Fes were further analyzed due to their close relationship than with Ft. Expression levels of flavonoid biosynthesis gene FLS1 (Flavonol synthase 1) were similar in Fea and Ft, and much higher than in Fes, which was validated by qRT-PCR. This suggests that FLS1 transcript levels may be associated with rutin accumulation in filling stage seeds of buckwheat species. Further, we explored transcription factors by iTAK, and multiple gene families were identified as being involved in the coordinate regulation of metabolism and development. Our extensive transcriptomic data sets provide a complete description of metabolically related genes that are differentially expressed in filling stage buckwheat seeds and suggests that FLS1 is a key controller of rutin synthesis in buckwheat species. FLS1 can effectively convert dihydroflavonoids into flavonol products. These findings provide a basis for further studies of flavonoid biosynthesis in buckwheat breeding to help accelerate flavonoid metabolic engineering that would increase rutin content in cultivars of common buckwheat.

Enhanced rutin accumulation in tobacco leaves by overexpressing the NtFLS2 gene.

Rutin, one of the metabolites of the flavonoid pathway, shows great potential in industrial applications as a key component in pharmaceutical medicines and biological pesticides. Although the genetic manipulation of transcription factors (TFs) could increase rutin levels in plants, the accompanying accumulation of structurally similar chemicals complicates industrial rutin extraction. In this study, we demonstrated remarkably elevated rutin content (3.5-4.4-fold relative to controls) in transgenic tobacco plants by overexpressing NtFLS2. The levels of other intermediates in the branch pathway did not change much except for a moderate increase of kaempferol-3-O-rutinoside. Furthermore, the transcript levels of pathway genes in transgenic lines were comparable with controls, indicating genetic engineering did not significantly alter the branch pathway. Additionally, the transgenic tobacco plants appeared normal except for a flower color change from light red to white suggesting that it could be a valuable material for industrial extraction of rutin.

Impact of light quality on flavonoid production and growth of Hyptis marrubioides seedlings cultivated in vitro

Hyptis marrubioides Epling, Lamiaceae, a species from Brazilian Cerrado, has been used against gastrointestinal infections, skin infections, pain, and cramps. Herein, H. marrubioides seedlings were cultured in vitro under different wavelengths (white, blue, green, red, and yellow) with 50μmolm−2s−1 irradiance and a 16-h photoperiod. After 20 and 30 days of cultivation, shoot length, leaf number, fresh mass, and dry mass were evaluated. The flavonoid rutin content was determined by the HPLC-DAD method. The shoots were longer in plants cultivated under yellow (16.603±0.790cm, 1.8-fold), red (15.465±0.461cm, 1.7-fold), and green (14.677±0.737cm, 1.6-fold) lights than in control plants exposed to white light (9.203±0.388cm). The number of leaves increased in plants exposed to red (23.425±1.138, 1.1-fold) and green (22.725±1.814, 1.1-fold) lights, compared to control plants (20.133±0.827). Fresh (0.665±0.048g, 1.2-fold) and dry (0.066±0.005g, 1.3-fold) mass of seedlings were the highest in seedlings grown under red light, compared to seedlings grown under white light (0.553±0.048 and 0.028±0.004, respectively). However, rutin production was higher under white (0.308mgg−1 of dry weight) and blue lights (0.298mgg−1 of dry weight). Thus, red light induces plant growth and increases leaf number and dry weight in in vitro-cultivated H. marrubioides, whereas blue and white lights promote the greatest rutin accumulation.