Flavonol Content Research Articles

Divergent effects of azithromycin on purple corn (Zea mays L.) cultivation: Impact on biomass and antioxidant compounds.

The present study assessed the impact of using irrigation water contaminated with Azithromycin (AZM) residues on the biomass and antioxidant compounds of purple corn; for this purpose, the plants were cultivated under ambient conditions, and the substrate used consisted of soil free from AZM residues, mixed with compost in a ratio of 1:1 (v/v). The experiment was completely randomized with four replications, with treatments of 0, 1, 10, and 100 μg/L of AZM. The results indicate that the presence of AZM in irrigation water at doses of 1 and 10 μg/L increases the weight of dry aboveground biomass, while at an amount of 100 μg/L, it decreases. Likewise, this study reveals that by increasing the concentration of AZM from 1 to 10 μg/L, total polyphenols and monomeric anthocyanins double, in contrast, with an increase to 100 μg/L, these decrease by 44 and 53%, respectively. It has been demonstrated that purple corn exposed to the antibiotic AZM at low doses has a notable antioxidant function in terms of DPPH and ORAC. The content of flavonols, phenolic acids, and flavanols increases by 57, 28, and 83%, respectively, when the AZM concentration is from 1 to 10 μg/L. However, with an increase to 100 μg/L, these compounds decrease by 17, 40, and 42%, respectively. On the other hand, stem length, root length, and dry weight of root biomass are not significantly affected by the presence of AZM in irrigation water.

Estimation of total phenolic content and total flavonol content in leaves and stem extracts of Ventilago maderaspatana Gaertn. and leaves, stem and stem bark extracts of Ziziphus xylopyrus (RETZ) Willd

Estimation of total phenolic content and total flavonol content in leaves and stem extracts of Ventilago maderaspatana Gaertn. and leaves, stem and stem bark extracts of Ziziphus xylopyrus (RETZ) Willd

Viticultural Climate Indexes and Their Role in The Prediction of Anthocyanins and Other Flavonoids Content in Seedless Table Grapes

Background: Viticulture bioclimatic indexes like the Heliothermal Index (HI), Cool Night Index (CI), and Dryness Index (DI), can be used to assess the influence of climate on grapes’ quality. Methods: HI, CI, and DI + total seasonal irrigation were utilized to assess the effect of climate on the flavonoids content and composition of two Vitis vinifera seedless varieties, ‘Summer Royal’ and ‘Crimson Seedless’, both grown in Apulia (Southern Italy). Results: The flavonoids content was significantly affected by variety and climate conditions on the base of HI, CI, and DI + total seasonal irrigation. Factor analysis applied to climate indexes and flavonoids showed that anthocyanins and flavonols were negatively and positively correlated to CI in both varieties, respectively. Additionally, warmer night temperatures determined higher fla-van-3-ols. HI increase promoted anthocyanins, flavonols, and flavan-3-ols content in Crimson Seedless, whilst it induced an opposite trend in Summer Royal. Finally, DI + total seasonal irrigation showed to be positively linked to flavonols content and negatively linked to anthocyanins content just in the case of Crimson Seedless. Significant regression models were also determined between climate indexes and productive parameters (i.e., yield, TSS, TA, pH, bunch, and berry weight). Conclusions: Climate indexes HI, CI, and DI + total seasonal irrigation showed an effect on quality grape parameters like flavonoids and contributed to building predictive models when new climatic zones are going to be evaluated for the production of table grapes.

Insight into Bioactive Compounds, Antioxidant and Anti-Diabetic Properties of Rosehip (Rosa canina L.)-Based Tisanes with Addition of Hibiscus Flowers (Hibiscus sabdariffa L.) and Saffron (Crocus sativus L.)

Tisane is a fruit or herbal infusion, commonly referred to as herbal tea. These products are consumed as part of a balanced diet, which is closely related to the trend of a healthier lifestyle. In this work, tisanes prepared from rosehip (R), and herbal mixtures containing rosehip/hibiscus flowers (R/H) and rosehip/hibiscus flowers/saffron (R/H/S) were studied. Rosehip was dried by the convective drying method at 40, 50 and 60 °C. Total phenolic content (TPC), total flavonoid content (TFC), total flavonol content (TFlC), total anthocyanin content (TAC), antioxidant properties (DPPH∙ and ABTS∙+ assays) and in vitro inhibitory potential toward α-amylase of tisanes were examined. The highest TPC (based on dry weight (dw)) was measured in tisane obtained from rosehip dried at 60 °C (37.84 mg GAE/g dw). Tisanes prepared from a R/H/S mixture had the highest values of TFC (4.66–6.13 mg QUE/g dw), TFlC (2.67–3.98 mg QUE/g dw) and TAC (1.35–2.27 mg Cy 3-glc/g dw). The highest DPPH∙ scavenging activity (53.42 mg TE/g dw) was measured in rosehip (dried at 60 °C) tisane, whereas tisane prepared from a rosehip (dried at 60 °C)/hibiscus mixture expressed the best ABTS∙+ scavenging activity (107.44 mg TE/g dw). All tisane samples expressed high inhibitory potential toward α-amylase, with the highest activity of 85.03% and 89.90%, measured for tisanes prepared from rosehip/hibiscus flowers mixture (rosehip dried at 50 and 60 °C, respectively).

Mutation in shoot-to-root mobile transcription factor, ELONGATED HYPOCOTYL 5, leads to low nicotine levels in tobacco

Tobacco remains one of the most commercially important crops due to the parasympathomimetic alkaloid nicotine used in cigarettes. Most genes involved in nicotine biosynthesis are expressed in root tissues; however, their light-dependent regulation has not been studied. Here, we identified the ELONGATED HYPOCOTYL 5 homolog, NtHY5, from Nicotiana tabacum and demonstrated that NtHY5 could complement the Arabidopsis thaliana hy5 mutant at molecular, morphological and biochemical levels. We report the development of CRISPR/Cas9-based knockout mutant plants of tobacco, NtHY5CR, and show down-regulation of the nicotine and phenylpropanoid pathway genes leading to a significant reduction in nicotine and flavonol content, whereas NtHY5 overexpression (NtHY5OX) plants show the opposite effect. Grafting experiments using wild-type, NtHY5CR, and NtHY5OX indicated that NtHY5 moves from shoot-to-root to regulate nicotine biosynthesis in the root tissue. Shoot HY5, directly or through enhancing expression of the root HY5, promotes nicotine biosynthesis by binding to light-responsive G-boxes present in the NtPMT, NtQPT and NtODC promoters. We conclude that the mobility of HY5 from shoot-to-root regulates light-dependent nicotine biosynthesis. The CRISPR/Cas9-based mutants developed, in this study; with low nicotine accumulation in leaves could help people to overcome their nicotine addiction and the risk of death.

Effects of yellowing and drying treatment temperatures on the taste of autumn green tea

This study aimed to reduce the bitterness and astringency properties of autumn green tea using different yellowing and drying treatments. The results showed that as the yellowing temperature increased, the contents of tea polyphenols, gallated catechins, flavonol glycosides, and bitter amino acids decreased, while the content of soluble sugar and flavonols increased. The tea sample (YEL35 °C) subjected to yellowing treatment at 35 °C exhibited weak bitterness and astringency intensities and a relatively low content of flavonol glycosides. As the drying temperature increased, the content of gallated catechins decreased. In addition, the tea sample (DRY75 °C) subjected to drying treatment at 75 °C exhibited weak bitterness and astringency intensities, the highest contents of umami amino acids and Thea, and a relatively low content of gallated catechins. Multivariate statistical analysis revealed that vitexin-2-O-rhamnoside, pferol-3-O-rutinoside, myricetin-3-O-galactoside, and quercetin-3-O-glucoside played an important role in the astringency property of the tea. In addition, Asn, Thr, Pro, and Met were positively correlated with umami. Hence, the quality of autumn green tea was improved under optimal yellowing and drying temperatures of 35 and 75 °C, respectively.

Oxidative stress is the active pathway in canola seed aging, the role of oxidative stress in the development of seedlings grown from aged canola seed

The widespread use of canola in the food sector has led to accelerated product growth, making it the second largest crop in the world. The analysis showed an increase in the content of proline (13.6%), H2O2 (12.7%), the levels of lipid peroxidation (30.7%), and antioxidant capacity (25.7%) in aged canola seed. The activity of CAT, SOD, and GPX enzymes increased by 1.40, 2.51, and 5.93 times respectively, while GR activity decreased by 8.8% in aged canola seed as compared to the control. An increase in GSSG content to 2.57 times and a decrease in GSH content of 0.76 times were observed in aged canola seeds. The increase in oxidative stress indices and the activity of antioxidant enzymes in canola seeds under accelerated aging indicate the role of free radicals in aging. Amylase enzyme activity increased 2.57 times in aged canola seed. Oxidative stress causes changes in the biological structures of seeds including cell membranes, lipids, pfroteins, and even in different tissue layers of seeds, which form different dimensions of the aging process. The analysis of canola seeds under accelerated aging showed that although aging reduced seed germination by 70%, the seedlings obtained from the seeds with the ability to germinate showed changes in the metabolic pathways of carbohydrates (0.26 times reduction) and proteins (1.36 times increase) of the seedlings. The phenolic compounds, flavonoid, and flavonol content of seedlings from aged seeds increased by 12.7%, 12.4%, and 12.1%, respectively. These seedlings showed significant changes in oxidative stress indexes compared to the control seedling.

Effect of halophyte-based management in physiological and biochemical responses of tomato plants under moderately saline greenhouse conditions

Salinity, both in irrigation water and in soils, is one of the major abiotic constraints for agriculture activity worldwide. Phytodesalinization is a low-cost plant-based bioremediation strategy that can effectively amend salt-affected soils by cultivating salt tolerant plants. However, very few studies have evaluated the use of halophyte plants in crop management systems. In this work, we apply two different tomato crop management strategies involving the halophyte Arthrocaulon macrostachyum L. in a moderately saline soil: intercropping (mixed cultivation) and sequential cropping (cultivation of tomato where halophytes were previously grown). We investigated the effect of the different crop managements in some physiological and biochemical variables in tomato plants, including mineral nutrients content, photosynthesis, chlorophyll and flavonol contents, antioxidant metabolism and fruit production and quality. At soil level, both intercropping and sequential cropping decreased chloride content, sodium adsorption ratio and electrical conductivity, leading to reduced soil salinity. In tomato plants, halophyte-dependent management improved nutrient homeostasis and triggered a mild oxidative stress, whereas photosynthesis performance was enhanced by intercropping. In tomato fruits, the sequential cropping led to a 27% production increase and a slight decrease in the soluble sugar contents. We suggest the use of A. macrostachyum, and hence of halophyte plants, as an environmentally friendly phytoremediation strategy to improve plant performance while improving crop production, leading to a more sustainable agriculture and enhancing biodiversity.

Elderberry Lipophilic and Hydrophilic Bioactive Compounds: Characterization and Extract Encapsulation.

There are few studies on the use of elderberry in the food industry, and its form of application differs between the different studies. Therefore, the objective of this study is to describe a procedure for obtaining a stabilized product with a high content of hydrophilic bioactive compounds (encapsulated elderberry extract). Moreover, the solid residue resulting from the extraction of the polyphenols was characterized, and the lipophilic compounds retained in this residue were analyzed. The results show an important antioxidant activity of the extracts obtained, mainly linked to the high content of anthocyanins, hydroxycinnamic acids, and flavonols. The lipophilic bioactive compounds were characterized by a high content of essential fatty acids and high proportions of tocopherols. The information and results of the present study provide novel information about both lipophilic and hydrophilic compounds for the integral valorization of elderberries to promote a circular economy strategy.

The IAA17.1/HSFA5a module enhances salt tolerance in Populus tomentosa by regulating flavonol biosynthesis and ROS levels in lateral roots.

Auxin signaling provides a promising approach to controlling root system architecture and improving stress tolerance in plants. However, how the auxin signaling is transducted in this process remains unclear. The Aux indole-3-acetic acid (IAA) repressor IAA17.1 is stabilized by salinity, and primarily expressed in the lateral root (LR) primordia and tips in poplar. Overexpression of the auxin-resistant form of IAA17.1 (IAA17.1m) led to growth inhibition of LRs, markedly reduced salt tolerance, increased reactive oxygen species (ROS) levels, and decreased flavonol content. We further identified that IAA17.1 can interact with the heat shock protein HSFA5a, which was highly expressed in roots and induced by salt stress. Overexpression of HSFA5a significantly increased flavonol content, reduced ROS accumulation, enhanced LR growth and salt tolerance in transgenic poplar. Moreover, HSFA5a could rescue the defective phenotypes caused by IAA17.1m. Expression analysis showed that genes associated with flavonol biosynthesis were altered in IAA17.1m- and HAFA5a-overexpressing plants. Furthermore, we identified that HSFA5a directly activated the expression of key enzyme genes in the flavonol biosynthesis pathway, while IAA17.1 suppressed HSFA5a-mediated activation of these genes. Collectively, the IAA17.1/HSFA5a module regulates flavonol biosynthesis, controls ROS accumulation, thereby modulating the root system of poplar to adapt to salt stress.

Comparative analysis of volatile compounds and functional components in fresh and dried monk fruit (Siraitia grosvenorii)

Monk fruit (Siraitia grosvenorii) is a medicinal and edible plant that is often used to prepare tea and alleviate coughs in China. Most of the S. grosvenorii available on the market is dried. However, the drying process affects the composition and content of the chemical components in the plants. To date, there have been few studies that have compared the chemical composition in fresh and dried S. grosvenorii. The chemical composition of fresh and dried plant tissue was analyzed using gas chromatography-mass spectrometry, high-performance liquid chromatography, and spectrophotometry, and their statistical differences were compared. The effect of altitude on the chemical composition of S. grosvenorii was also studied. The volatile compounds in both fresh and dried S. grosvenorii primarily consisted of alkanes, alkenes, organic acids, and aldehydes, which accounted for 93.62 % and 87.64 % of the volatiles in fresh and dried S. grosvenorii tissues, respectively. The most abundant volatile compound was n-hexadecanoic acid (fresh: 31.73 %, dried: 37.49 %). After hot air drying, the contents of alkanes, alkenes, esters, and alcohols increased by 5.76 %, 2.68 %, 2.35 %, and 2.96 %, respectively, whereas the contents of aldehydes decreased by 13.94 %. Compared with fresh S. grosvenorii, the levels of mogroside V, vitamin C, protein, fructose, and glucose in the dried tissue of this plant decreased significantly by 13.13 %, 100.0 %, 46.31 %, 40.39 %, and 75.07 %, respectively, while the contents of total phenolics, total flavones, total flavonols, and sucrose increased significantly by 144.9 %, 84.94 %,142.1 %, and 128.0 %, respectively. The contents of fructose and glucose significantly positively correlated with altitude.

Non-Destructive Assessment of Leaf Chlorophyll and Epidermal Flavonoids in Two Tomato Cultivars (Solanum lycopersicum L.) Grown Under Different Trichoderma Spp. Treatments

Summary The purpose of this study is to examine the effects of different Trichoderma spp. treatments (T1: Trichoderma harzianum, T2: Trichoderma brevicompactum, and T3: T1 + T2) on two tomato cultivars (‘Narvik’ and ‘Gružanski zlatni’) by the non-destructive monitoring of chlorophyll (Chl) and epidermal flavonol (Flav) indices and nitrogen balance index (NBI) in their leaves. The main objectives were to compare the responses of tomato cultivars considered (grown in a greenhouse) to different Trichoderma strains and a combination of Trichoderma strains. Variations in the Chl, Flav, and NBI values obtained were significantly influenced by nearly all the factors examined (namely the tomato cultivar, experimental week, and treatment), the interaction of which was found significant for all the parameters analyzed. The results obtained indicate that the combinations of strains in the T3 treatment markedly enhanced the Chl content in the ‘Narvik’ cultivar in some experimental weeks. Moreover, reduced NBI values were determined in the Trichoderma-treated ‘Narvik’ plants due to the increased flavonol content, which indicates a shift from primary to secondary metabolism. Further research, including the same cultivars and treatments, is warranted under field conditions to evaluate the physiological responses of the ‘Narvik’ and ‘Gružanski zlatni’ tomato cultivars in a multiple-stressor environment.

Hyperspectral images of grapevine leaves including healthy leaves and leaves with biotic and abiotic symptoms

A hyperspectral imaging database was collected on two hundred and five grape plant leaves. Leaves were measured with a hyperspectral camera in the visible/near infrared spectral range under controlled conditions. This dataset contains hyperspectral acquisition of grape leaves of seven different varieties. For each variety, acquisitions were performed on healthy leaves and leaves with foliar symptoms caused by different grapevine diseases showing clear symptoms of biotic or abiotic stress on other organs. For each leaf, chemical measurements such as chlorophyll and flavonol contents were also performed.

Polyphenolic Composition, Antioxidant and Antiproliferative Activity of Edible and Inedible Parts of Cultivated and Wild Pomegranate (Punica granatum L.).

The aim of this study is to determine and compare the antioxidant and antiproliferative activities of juices and extracts of the peel, aril and membrane of the cultivated and wild pomegranate fruits. The content of total phenols, total flavonoids, total flavonols, total flavan-3-ols and total anthocyanins was determined spectrophotometrically. The individual phenolics were quantified by HPLC. Antioxidant activity was determined by DPPH and ABTS tests and neutralisation of hydroxyl radical, while the antiproliferative activity was measured in vitro by sulforhodamine B (SRB) assay. Total phenolics were statistically highest in wild pomegranate peel extract, expressed in gallic acid equivalents, 340.92 mg/g (p<0.05), while total flavonoid content was the highest in cultivated pomegranate peel extract, expressed in quercetin equivalents, 31.84 mg/g (p<0.05). The sample of wild pomegranate peel extract showed the highest antioxidant activity with respect to free DPPH and ABTS radicals. The samples of cultivated pomegranate peel and membrane extracts had almost identical and the strongest effect on the inhibition of hydroxyl radicals (41.24 and 41.23 μg/mL, respectively). The sample of wild pomegranate peel extract showed the strongest effect on the growth inhibition of all tested tumour cell lines. In this study, the bioactivity of different parts of cultivated and wild pomegranates was determined and compared. In the available literature, the individual antioxidant and antiproliferative activity of only some parts of the pomegranate fruit was investigated. All parts of the pomegranate fruit were investigated, including the membrane, which was barely analysed in other works. The wild pomegranate has also been less analysed in previous studies. Future research should focus on in vivo studies of the obtained pomegranate samples.

Bioactivity-Guided Isolation and Antihypertensive Activity of Citrullus colocynthis Polyphenols in Rats with Genetic Model of Hypertension.

Background and Objectives: Citrullus colocynthis belongs to the Cucurbitaceae family and is a wild medicinal plant used in folk literature to treat various diseases. The purpose of the current study was to explore the antihypertensive and antioxidant potentials of Citrullus colocynthis (CC) polyphenol-rich fractions using a spontaneous hypertensive rat (SHR) model. Materials and Methods: The concentrated aqueous ethanol extract of CC fruit was successively fractioned using solvents of increasing polarity, i.e., hexane, chloroform, ethyl acetate and n-butanol. The obtained extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC) and total flavonol content (TOF). Moreover, the CC extracts were further evaluated for radical scavenging capacity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays and antioxidant activity using inhibition of linoleic acid peroxidation and determination of reducing potential protocols. The phytochemical components were characterized by HPLC-MWD-ESI-MS in positive ionization mode. Results: The results showed that ethyl acetate fraction (EAF) exhibited a higher content of phenolic compounds in term of TPC (289 mg/g), TFC (7.6 mg/g) and TOF (35.7 mg/g). EAF showed higher antioxidant and DPPH and ABTS scavenging activities with SC50 values of 6.2 and 79.5 µg/mL, respectively. LCMS analysis revealed that twenty polyphenol compounds were identified in the EAF, including phenolic acids and flavonoids, mainly myricetin and quercetin derivatives. The in vivo antihypertensive activity of EAF of CC on SHR revealed that it significantly decreased the mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressures (DBP) and pulse pressure (PP) as compared to normal and hypertensive control groups. Moreover, EAF of CC significantly reduced the oxidative stress in the animals in a dose-dependent manner by normalizing the levels of superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NOx) and total antioxidant capacity (TAC). Furthermore, the treatment groups, especially the 500 mg of EAF per kg body weight (EA-500) group, significantly (p ≤ 0.05) improved the electrocardiogram (ECG) pattern and pulse wave velocity (PWV). Conclusion: It was concluded that the EAF of CC is a rich source of polyphenols and showed the best antioxidant activity and antihypertensive potential in SHR.

HaMYBA-HabHLH1 regulatory complex and HaMYBF fine-tune red flower coloration in the corolla of sunflower (Helianthus annuus L.)

Sunflowers are well-known ornamental plants, while sunflowers with red corolla are rare and the mechanisms underlying red coloration remain unclear. Here, a comprehensive analysis of metabolomics and transcriptomics on flavonoid pathway was performed to investigate the molecular mechanisms underlying the differential color formation between red sunflower Pc103 and two yellow sunflowers (Yr17 and Y35). Targeted metabolomic analysis revealed higher anthocyanin levels but lower flavonol content in Pc103 compared to the yellow cultivars. RNA-sequencing and phylogenetic analysis identified multiple genes involved in the flavonoid pathway, including series of structural genes and three MYB and bHLH genes. Specifically, HaMYBA and HabHLH1 were up-regulated in Pc103, whereas HaMYBF exhibited reduced expression. HaMYBA was found to interact with HabHLH1 in vivo and in vitro, while HaMYBF does not. Transient expression analysis further revealed that HabHLH1 and HaMYBA cooperatively regulate increased expression of dihydroflavonol 4-reductase (DFR), leading to anthocyanin accumulation. On the other hand, ectopic expression of HaMYBF independently modulates flavonol synthase (FLS) expression, but hindered anthocyanin production. Collectively, our findings suggest that the up-regulation of HaMYBA and HabHLH1, as well as the down-regulation of HaMYBF, contribute to the red coloration in Pc103. It offers a theoretical basis for improving sunflower color through genetic engineering.

Temperature differences between sites lead to altered phenylpropanoid metabolism in a varietal dependent manner.

Elevated temperature has already caused a significant loss of wine growing areas and resulted in inferior fruit quality, particularly in arid and semi-arid regions. The existence of broad genetic diversity in V. vinifera is key in adapting viticulture to climate change; however, a lack of understanding on the variability in berry metabolic response to climate change remains a major challenge to build ad-hoc strategies for quality fruit production. In the present study, we examined the impact of a consistent temperature difference between two vineyards on polyphenol metabolism in the berries of 20 red V. vinifera cultivars across three consecutive seasons (2017-2019). The results emphasize a varietal specific response in the content of several phenylpropanoid metabolites; the interaction factor between the variety and the vineyard location was also found significant. Higher seasonal temperatures were coupled with lower flavonol and anthocyanin contents, but such reductions were not related with the level of expression of phenylpropanoid related genes. Hierarchical clustering analyses of the metabolic data revealed varieties with a location specific response, exceptional among them was Tempranillo, suggesting a greater susceptibility to temperature of this cultivar. In conclusion, our results indicate that the extensive genetic capacity of V. vinifera bears a significant potential to withstand temperature increase associated with climate change.

Study of Opuntia humifusa: phytochemical analysis of aqueous fruit extract and green synthesis of Ag2O nanoparticles

Ag2O nanoparticle synthesis was carried out via co-precipitation technique based on using AgNO3 and secondary metabolites present in the aqueous extract of Opuntia humifusa fruit for the first time. The amount of measured total phenol, flavonoid content, flavone, and flavonol content, and anthocyanin were 38.46 μg eq gallic acid mg−1 extract, 8.34 μg eq quercetin mg−1 extract, 0.614 μg eq quercetin mg−1 DW, and 3.1 mmol L−1, respectively. Moreover, the predominant phenolic compound was gallic acid. Catechin and chlorogenic acid were found in both fruit juice and fruit aqueous extract. Scanning electron microscopy (SEM) of Ag2O-NPs showed the average particle size was 10.58 nm. Scanning electron microscopy, X-ray diffraction Spectroscopy, and UV/visible spectrometry also confirmed the synthesis. This study then focuses on IC50 and NO amount differences before and after the synthesis of Ag2O-NPs which were 448.29 and 101.38 μg mL−1 for IC50 and 35.7% and 62.6% for NO, respectively.

Integrated analysis of multiple metabolome and transcriptome revealed the accumulation of flavonoids and associated molecular regulation mechanisms in Rubus chingii Hu at different developmental stages

The traditional Chinese herb Rubus chingii Hu (R. chingii) is widely used in clinical practice due to its beneficial effects. Flavonoids are the important class of pharmacological substances in R. chingii, however, the molecular mechanism underlying the differences in active flavonoid contents in R. chingii at different developmental stages remain poorly understood. In this experiment, we selected four developmental stages (GG, GY, YR, RR) of R. chingii as the research material. We studied the untargeted and targeted metabolic profiles of flavonoids in different periods of R. chingii, combining full-length and comparative transcriptome analyses. Functional analyses were conducted on genes implicated in flavonoid differences. GG and RR displayed relatively higher and lower contents of flavonols, flavones, flavanols, flavanones, and isoflavonoid, respectively. RNA-seq analyses showed structural genes such as RcPAL, RcC4H, Rc4CL, RcCHS, RcCHI, RcF3H, RcF3′H, and RcFLS in flavonoid biosynthesis pathway were upregulated in GG, which were essential for the accumulation flavanones, flavones, and flavonols (effective components). qRT-PCR analyses investigated that six structural genes RcCHI, RcF3H, 2 RcCHS, and 2 Rc4CL, two TFs RcMYB308 and RcMYB123 had a consistent expression pattern with which in transcriptome. Also, an interaction network showed that the RcMYB308 could positively regulate Ka3R, Qu, Qu3G, AS, Hy, Ti through RcF3H. Furthermore, Subcellular localization analysis revealed that RcMYB308 was localization to the nucleus. In tobacco, RcMYB308 was overexpressed, resulting in higher flavonoids, RcF3H, RcF3′H, RcCHI, and RcFLS. RcMYB308 upregulated RcF3H in dual-luciferase assays. These results provide new insights for further understanding the molecular mechanism regulating flavonol biosynthesis in R. chingii fruit, and also provide a potential MYB regulator for molecular breeding of R. chingii.

Биологически активные вещества в цветках и листьях сортов сибирских ирисов

Abstract. In the last decade, garden varieties of Siberian iris (Iris sibirica L.) of the iris family (Iridaceae Juss.), which are valuable not only as ornamental plants, but also as a source of biologically active substances used in medicine and the perfume industry, have been very popular. Information on the presence of these substances in the generative and vegetative organs of the varieties of Siberian iris studied by us was not noted, which is the novelty and relevance of this work. The purpose of the study is a comparative study and assessment of the quantitative content of biologically active substances in the flowers and leaves of I sibirica and seven varieties from the Siberian irises (SIB) group cultivated in the forest-steppe zone of Western Siberia. Methods. The content of flavonols, catechins, carotenoids was determined by the spectrophotometric method, pectin substances by the carbazole-free spectrophotometric method and tannins by the titrimetric method. Results. The results of a comparative analysis of secondary metabolites in the aerial organs of irises showed that the content of tannins (1.3–3.2 times), flavonoids (1.5–4.6 times), catechins (5.0–6.3 times), carotenoids (2.6–9.5 times) higher in leaves than in flowers. The content of pectins is higher (3.5–9.5 times) and protopectins (1.2–1.9 times) in flowers. The varieties Fialcovy, Vals Katuni, Kassandra were distinguished by the highest indications for individual components. Variety and species specificity in the distribution of these components in the flowers and leaves of plants, as well as the influence of hydrometrological factors during the growing seasons of growth and development of 2020–2021, were noted. Scientific novelty. For the first time in the conditions of the forest-steppe zone of the Novosibirsk region, a comparative quantitative analysis of the content of tannins, flavonols, pectins, protopectins, catechins, carotenoids in the aboveground organs of Iris sibirica and its varieties: Baltik Blue, Blue Cup, Cambridge, Fialcovy, Kassandra, Mandy Morse, Vals Katuni was carried out.