Accumulation Of Total Flavonoids Research Articles

The WRKY46–MYC2 module plays a critical role in E-2-hexenal-induced anti-herbivore responses by promoting flavonoid accumulation

Volatile organic compounds (VOCs) play key roles in plant–plant communication, especially in response to pest attack. E-2-hexenal is an important component of VOCs, but it is unclear whether it can induce endogenous plant resistance to insects. Here, we show that E-2-hexenal activates early signaling events in Arabidopsis (Arabidopsis thaliana) mesophyll cells, including an H2O2 burst at the plasma membrane, the directed flow of calcium ions, and an increase in cytosolic calcium concentration. Treatment of wild-type Arabidopsis plants with E-2-hexenal increases their resistance when challenged with the diamondback moth Plutella xylostella L., and this phenomenon is largely lost in the wrky46 mutant. Mechanistically, E-2-hexenal induces the expression of WRKY46 and MYC2, and the physical interaction of their encoded proteins was verified by yeast two-hybrid, firefly luciferase complementation imaging, and in vitro pull-down assays. The WRKY46–MYC2 complex directly binds to the promoter of RBOHD to promote its expression, as demonstrated by luciferase reporter, yeast one-hybrid, chromatin immunoprecipitation, and electrophoretic mobility shift assays. This module also positively regulates the expression of E-2-hexenal-induced naringenin biosynthesis genes (TT4 and CHIL) and the accumulation of total flavonoids, thereby modulating plant tolerance to insects. Together, our results highlight an important role for the WRKY46–MYC2 module in the E-2-hexenal-induced defense response of Arabidopsis, providing new insights into the mechanisms by which VOCs trigger plant defense responses.

Metabolomics and network pharmacology profiling revealed soilless cultivation reduces the accumulation of harmful compounds in Houttuynia cordata

Houttuynia cordata Thunb (HCT), an important homologous plant, has extensive medicinal and food value. Traditional Chinese medicine may have therapeutic research value for inhibiting COVID-19 toxicity. HeadSpace Solid Phase Micro-Extraction Gas-Chromatography-Mass-Spectrometry (HS-SPME-GC–MS) was used in this study to examine the edible quality, differences in growth indicators, and metabolite differences of HCT under different cultivation media (soil, sand, peat, hydroponics). Additionally, network pharmacology was used to study the active substances and key targets of Houttuynia cordata against COVID-19. The experimental analysis indicated that hydroponics produced the highest HCT yield and that the soil culture produced the highest growth parameters such as dry rate, chlorophyll content, and vitamin C content. The sand culture produced the highest total protein content, and the peat culture resulted in the highest accumulation of total flavonoids. However, compared with the soilless culture, the soil culture's environment produced more benzene and substituted derivatives and more carboxylic acids and derivatives. Hydroponics reduces the accumulation of harmful metabolites and enhances the accumulation of medicinal components in HCT. In summation, HCT is suitable for soilless cultivation and shows demonstrates strong performance in medicinal quality and growing development under hydroponics.

Analysis of Brachypodium distachyon UVR8 reveals conservation in UV-B receptors.

The Ultraviolet Resistance Locus 8 (UVR8) in plants recognizes ultraviolet-B (UV-B) light and plays a crucial role in regulating plant growth through a series of signal transduction events. However, the UVR8 in monocotyledon crops has not yet been systematically analysed. We identified BdUVR8 (BRADI_3g45740) from the genome of Brachypodium distachyon, a relative of wheat, by analysing the phylogenetic tree, the gene expression pattern, detecting accumulation of UV-B response metabolites, and checking for phenotype recovery. The BdUVR8 protein sequence is similar to the known UVR8 of other species. The phylogenetic tree of UVR8 shows clear divergence between dicotyledons and monocotyledons. Expression analysis revealed that UV-B downregulates BdUVR8 by 70% and upregulates the chalcone synthase (BdCHS) gene 3.4-fold in B. distachyon. The pCAMBIA1300::BdUVR8-mCherry construct introduced into Arabidopsis uvr8 mutants showed that the BdUVR8 protein is localized in the cytoplasm and translocates into the nucleus in response to UV-B irradiation. The introduction of BdUVR8 into uvr8 rescued hypocotyl elongation caused by UV-B and restored expression of HY5, Chalcone synthase, and Flavanone 3-hydroxylase, as well as accumulation of total flavonoids. Together, our results show that BdUVR8 is a photoreceptor that perceives UV-B in B.distachyon.

Exogenous Melatonin Enhances the Yield and Secondary Metabolite Contents of Prunella vulgaris by Modulating Antioxidant System, Root Architecture and Photosynthetic Capacity

Melatonin (MT) plays a number of key roles in regulating plant growth and secondary metabolite accumulation. Prunella vulgaris is an important traditional Chinese herbal medicinal plant which is used for the treatment of lymph, goiter, and mastitis. However, the effect of MT on the yield and medicinal component content of P. vulgaris remains still unclear. In this research, we have examined the influence of different concentrations of MT (0, 50, 100, 200, 400 μM) on the physiological characteristics, secondary metabolite contents, and yield of P. vulgaris biomass. The results showed that 50-200 μM MT treatment had a positive effect on P. vulgaris. MT treatment at 100 μM greatly increased the activities of superoxide dismutase and peroxidase, the contents of soluble sugar and proline, and obviously decreased the relative electrical conductivity, the contents of malondialdehyde and hydrogen peroxide of leaves. Furthermore, it markedly promoted the growth and development of the root system, increased the content of photosynthetic pigments, improved the performance of photosystems I and II and the coordination of both photosystems, and enhanced the photosynthetic capacity of P. vulgaris. In addition, it significantly increased the dry mass of whole plant and spica and promoted the accumulation of total flavonoids, total phenolics, caffeic acid, ferulic acid, rosmarinic acid, and hyperoside in the spica of P. vulgaris. These findings demonstrated that the application of MT could effectively activate the antioxidant defense system of P. vulgaris, protect the photosynthetic apparatus from photooxidation damage, and improve the photosynthetic capacity and the root absorption capacity, thereby promoting the yield and accumulation of secondary metabolites in P. vulgaris.

Exploration of the effect of blue laser light on microRNAs involved in functional metabolism in D. officinale through RNA sequencing

Dendrobium officinale has remarkable medicinal functions and high economic value. Laser light sources are different from ordinary light sources in terms of the light emission mechanism and play important roles regulating functional metabolite synthesis in D. officinale. However, the mechanism by which miRNAs participate in regulating the D. officinale response to blue laser irradiation has not been reported. Previous studies found that the number of red leaves on plants treated with blue laser light was greater than that on plants treated with blue light and white light, and blue laser light was most effective at promoting the accumulation of total flavonoids, polysaccharides and alkaloids. RNA-seq was used to analyse the difference in the effects of lasers on D. officinale. KEGG analysis of the target genes of differentially expressed (DE) miRNAs showed that there were multiple blue laser response pathways, among which peroxisome, nitrogen metabolism, terpenoid biosynthesis, porphyrin and chlorophyll metabolism played central roles. Cytoscape interaction analysis of DE miRNA targets showed that novel_miR_248 most likely participates in the influence of blue laser irradiation on D. officinale. Content verification in D. officinale showed that blue laser light could also increase the total terpene, chlorophyll levels, nitrate reductase, glutamine synthase and glutamate dehydrogenase. Combined with the qPCR results, these findings showed that miR395b, miR827 and miR319l may participate in the blue laser signalling network through their target genes and then regulate the accumulation of functional metabolites in D. officinale. This study provides a scientific basis for the high-yield production of D. officinale.

Bioremediation of Cadmium Toxicity in Wheat (Triticum aestivum L.) Plants Primed with L-Proline, Bacillus subtilis and Aspergillus niger.

Cadmium toxicity is one of the deleterious abiotic factors that reduce wheat production. Two different cultivars (Akbar and Dilkash) were compared for their cadmium (0, 40 and 80 mg/kg) tolerance and responses towards Bacillus subtilis NA2, Aspergillus niger PMI-118 and L-proline. Both microbes were tested for heavy metal tolerance and production of various plant hormones and biological active enzyme characteristics under normal and cadmium stress. A completely randomized design (two cultivars × four treatments × three cadmium levels × three replicates) was adopted using distilled water as a control. The growth promotion potential of these strains under cadmium stress was determined by N-fixation, IAA synthesis, P-solubilization, amylase and proteases production. A pot experiment under controlled conditions was conducted to evaluate the effect of bacteria, fungi, and L-proline under cadmium stress. It was indicated from the result that plant biomass (46.43%), shoot length (22.40%), root length (25.06%), chlorophyll (17.17%), total sugars (27.07%), total proteins (86.01%) and ascorbic acid (83.27%) were improved with inoculation under control and cadmium stress. The accumulation of total flavonoids (48.64%), total phenolics (24.88%), hydrogen peroxide (53.96%) and activities of antioxidant enzymes CAT (26.37%) and APX (43.71%) were reduced in the plants treated with bacteria, fungi and L-proline than those under control. With parallel aids, Bacillus subtilis NA2 showed a higher cadmium tolerance and plant growth stability as compared to Aspergillus niger PMI-118 and L-proline and may be adopted in the future.

Multivariate comparative analysis of chemical constituent changes and antioxidant properties of polysaccharides in ribes stenocarpum maxim. at different maturity stages on the Qinghai-Tibet Plateau

Ribes stenocarpum Maxim. (RSM) is abundant but less known in the Qinghai-Tibet Plateau, so far, it is still in the wild state and has not been effectively developed and utilized. Based on this, the fruits RSM at seven different picking time were used to quantify the contents of total polysaccharides (TP), total flavonoids (TF), titratable acids (TA), total triterpene acids (TTA), fruit oils (FO) and vitamin C (VC), and to investigate the relationship between polysaccharides structure and antioxidant activity. The relationships between the chemical constituents of the samples and meteorological factors, antioxidant activity and polysaccharide structure were investigated using multivariate comparative analysis. The results revealed that the chemical constituents content varied considerably at different stages of maturity. TF (0.660 g kg−1 dw), TA (2.280 g kg−1 dw) was abundant in immature fruits and its content decreased with fruit maturity; on the contrary, FO (0.775 g kg−1 dw), VC (0.010 g kg−1 dw) was abundant in over- mature fruits and its content increased with time. TP (1.807 g kg−1 dw), on the other hand, was abundant in mature fruits. In addition, near surface air pressure and near surface precipitation had significant effects on the accumulation of TF, near surface air temperature and near surface air specific humidity on the accumulation of TA, and surface downward shortwave radiation on the accumulation of FO. The polysaccharide structure and monosaccharide composition of RSM differed significantly depending on the picking time. Moreover, glucose and xylose had significant effects on antioxidant activity, and polysaccharides in the immature and over-mature stages had higher antioxidant activity. The study results suggested that the middle and end of September was the suitable picking period for RSM fruits. This study may provide a basis for the selection of picking period of RSM fruits.

Effects of vine water status on vine performance and grape composition of (Vitis vinifera L.) cv. 'Sultani Çekirdeksiz'

Drought caused by climate change increased the relevance of irrigation management in viticulture. In order to regulate irrigation strategies for Vitis vinifera L., their influences on vine performance, yield and quality attributes need to be understood. This study evaluates the effects of different irrigation schedulings on vine performance and grape composition in a vineyard of cv. ‘Sultani Çekirdeksiz’ (Sultana clone, H5) during three consecutive years (2015–2017). Three irrigation treatments were assayed: (i) full irrigation (FI), soil water content was completed to field capacity within one week intervals; (ii) DI65, applying 65% water of FI and (iii) DI35, applying 35% water of FI. Water stress caused by the deficit irrigation treatments limited vine performance in terms of vegetative development and yield. The highest phenolic content, antioxidant capacity and total flavonoid accumulation were obtained under DI35, although this treatment had lowest yield. In conclusion, DI65 (moderate stress) might result in a more balanced yield and grape quality attributes in comparison with FI and DI35.

Enhanced total flavonoid accumulation and alleviated growth inhibition of germinating soybeans by GABA under UV-B stress.

Germination of soybeans under ultraviolet-B (UV-B) treatment is a simple and effective way to enrich soybean isoflavones, but its mechanism of action is not yet clear. G-Aminobutyric acid (GABA) is a signaling molecule that is involved in the accumulation of secondary metabolites as well as the regulation of plant development and metabolism. In this study, the effects of exogenous GABA and its inhibitors on the physiological and biochemical, antioxidant systems, total flavonoid content, activity and gene expression of isoflavone metabolism related enzyme in germinating soybeans under UV-B treatment were investigated. Compared to UV-B treatment alone, soybean treated with GABA (5 mM) in combination with UV-B significantly increased sprout length, fresh weight, Ca2+ inward flow and peroxidase and catalase activities, and decreased malondialdehyde and H2O2 and O2˙− fluorescence intensity, while soybean treated with GABA inhibitor showed the opposite trend. Meanwhile, total flavonoid content increased by 11.2% and 6.7%, respectively, in 2- and 4 day-old soybeans under UV-B treatment, compared to UV-B treatment alone. Moreover, the application of GABA under UV treatment significantly increased the activity of phenylalanine ammonia-lyase and cinnamic acid-4-hydroxylase, with values increasing by 43.6% and 18.5%, respectively, in four-day-old soybean compared to UV treatment alone, which also increased the relative expression of key genes involved in isoflavone metabolism. The GABA inhibitor 3-mercaptopropionic acid blocked these occurrences. According to this research, GABA could operate as a signaling molecule to mediate isoflavone accumulation in soybean sprouts under UV radiation and stimulate soybean sprout growth.

The Sorghum (Sorghum bicolor) Brown Midrib 30 Gene Encodes a Chalcone Isomerase Required for Cell Wall Lignification.

In sorghum (Sorghum bicolor) and other C4 grasses, brown midrib (bmr) mutants have long been associated with plants impaired in their ability to synthesize lignin. The brown midrib 30 (Bmr30) gene, identified using a bulk segregant analysis and next-generation sequencing, was determined to encode a chalcone isomerase (CHI). Two independent mutations within this gene confirmed that loss of its function was responsible for the brown leaf midrib phenotype and reduced lignin concentration. Loss of the Bmr30 gene function, as shown by histochemical staining of leaf midrib and stalk sections, resulted in altered cell wall composition. In the bmr30 mutants, CHI activity was drastically reduced, and the accumulation of total flavonoids and total anthocyanins was impaired, which is consistent with its function in flavonoid biosynthesis. The level of the flavone lignin monomer tricin was reduced 20-fold in the stem relative to wild type, and to undetectable levels in the leaf tissue of the mutants. The bmr30 mutant, therefore, harbors a mutation in a phenylpropanoid biosynthetic gene that is key to the interconnection between flavonoids and monolignols, both of which are utilized for lignin synthesis in the grasses.

Comparative transcriptome analysis reveals the molecular mechanism of salt tolerance in Apocynum venetum

Apocynum venetum is a traditional Chinese medicinal herb with tolerance to various abiotic stresses, especially, salinity. However, only a few studies have investigated the salt-tolerant mechanism of this non-halophyte under salt stress at phenotypic and physiological levels. To explore the molecular mechanism of salinity tolerance in A. venetum, the global transcriptome profiles of seedling leaves under different salt-stress durations, using 200 mM NaCl, were analyzed. De novo assembly of approximately 715 million high-quality reads and approximately 105.61 Gb sequence data was performed. In total, 2822 differentially expressed genes (DEGs) were identified. DEGs were significantly enriched in flavonoid metabolism-related pathways such as “flavonoid biosynthesis” and “phenylpropanoid biosynthesis”. Most of these DEGs were downregulated under salt stress. However, genes encoding the non-selective cation channels and antioxidants were upregulated under salt stress, whereas most cell wall-related DEGs were downregulated. Consequently, the concentration of flavonoids decreased, whereas that of Na+ increased with exposure time. Thus, we hypothesized that the accumulation of Na+ in the leaves, which resulted in reduced flavonoid concentration under salt stress, directly led to a decrease in the salt tolerance of A. venetum. This was verified by overexpressing four flavonoid synthesis pathway genes in Arabidopsis. The transgenic plants showed higher salt tolerance than the wild-type plants due to the accumulation of total flavonoids. These physiological and transcriptome analyses of A. venetum revealed major molecular underpinnings contributing to the responses of A. venetum to salt stress, thereby improving our understanding of the molecular mechanisms underlying salt tolerance in A. venetum and plants in general. The findings serve as a basis for functional studies on and engineering strategies for plant salinity tolerance.

Investigation of flavonoid expression and metabolite content patterns during seed formation of Artemisia sphaerocephala Krasch.

AbstractFlavonoids are a group of phenolic secondary metabolites in plants that have important physiological, ecological and economic value. In this study, using the desert plant Artemisia sphaerocephala Krasch. as the sample material, the content and components of the total flavonoids in its seeds at seven different developmental stages were determined. In addition, the genes involved in flavonoid metabolism were identified by full-length transcriptome sequencing (third-generation sequencing technology based on PacBio RS II). Their expression levels were analysed by RNA-seq short reading sequencing, to reveal the patterns and regulation mechanisms of flavonoid accumulation during seed development. The key results were as follows: the content of total flavonoids in mature seeds was 15.05 mg g−1, including five subclasses: flavonols, chalcones, flavones, flavanones and proanthocyanidins, among which flavonols accounted for 45.78%. The period of rapid accumulation of flavonoids was 40–70 d following anthesis. The high expression of phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL) and UDP-glucose:flavonoids 3-o-glucosyltransferase (UF3GT) promoted the accumulation of total flavonoids, while the high expression of flavonoids 3′-hydroxylase (F3′H) and flavonols synthase (FLS) made flavanols the main component. Transcription factors such as the MYB-bHLH-WDR (MBW) complex and Selenium-binding protein (SBP) directly regulated the structural genes of flavonoid metabolism, while C2H2-type zinc finger (C2H2), Zinc-finger transcription factor (GATA), Dehydration-responsive element binding (DREB), Global Transcription factor Group E protein (GTE), Trihelix DNA-binding factors (Trihelix) and Phytochrome-interacting factor (PIF) indirectly promoted the synthesis of flavonoids through hormones such as brassinoidsteroids (BRs) and abscisic acid (ABA). These results provided valuable resources for the application of related genes in genetics and breeding.

Overexpression of an Apocynum venetum flavonols synthetase gene confers salinity stress tolerance to transgenic tobacco plants

Soil salinity is a major limiting factor for agricultural production, threatening food security worldwide. A thorough understanding of the mechanisms underlying plant responses is required to effectively counter its deleterious effects on crop productivity. Total flavonoid accumulation reportedly improves salinity tolerance in many crops. Therefore, we isolated the full-length cDNA of a flavonol synthetase (FLS) gene from Apocynum venetum (AvFLS). The gene contained a 1008-bp open reading frame encoding a protein composed of 335 amino acid residues. Multiple sequence alignment showed that the AvFLS protein was highly homologous to FLSs from other plants. AvFLS was expressed in leaves, stems, roots, flowers, and germinated seeds. Expression pattern analysis revealed that AvFLS was significantly induced by salinity stress. AvFLS overexpression in tobacco positively affected the development and growth of transgenic plants under salinity stress: root and seedling growth were inhibited to a lesser extent, while seed germination rate increased. Additionally, the overexpression of AvFLS under salinity stress resulted in an increase in total flavonoid content (1.63 mg g−1 in wild-type samples and 4.63 mg g−1 on average in transgenic samples), which accompanied the increase in the activity of antioxidant enzymes and inhibited the production of reactive oxygen species. Further, AvFLS-overexpressing transgenic tobacco plants absorbed more K+ than wild type plants, leading to an increased K+/Na+ ratio, which in turn contributed to the maintenance of Na+/K+ homeostasis. These findings suggest that an AvFLS-induced increase in total flavonoid content enhanced plant salinity tolerance, implying the importance of AvFLS gene responses to salinity stress.

Chitosan Elicitation Impacts Flavonolignan Biosynthesis in Silybum marianum (L.) Gaertn Cell Suspension and Enhances Antioxidant and Anti-Inflammatory Activities of Cell Extracts

Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S. marianum were exploited for their in vitro potential to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension cultures were maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 ± 1.7 g/L fresh weight (FW) and 17.7 ± 0.5 g/L dry weight (DW) productions. All chitosan treatments resulted in an overall increase in the accumulation of total flavonoids (5.0 ± 0.1 mg/g DW for 5.0 mg/L chitosan), total phenolic compounds (11.0 ± 0.2 mg/g DW for 0.5 mg/L chitosan) and silymarin (9.9 ± 0.5 mg/g DW for 0.5 mg/L chitosan). In particular, higher accumulation levels of silybin B (6.3 ± 0.2 mg/g DW), silybin A (1.2 ± 0.1 mg/g DW) and silydianin (1.0 ± 0.0 mg/g DW) were recorded for 0.5 mg/L chitosan. The corresponding extracts displayed enhanced antioxidant and anti-inflammatory capacities: in particular, high ABTS antioxidant activity (741.5 ± 4.4 μM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan, whereas highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 ± 1.3 %), secretory phospholipase A2 (sPLA2, 33.9 ± 1.3 %) and 15-lipoxygenase (15-LOX-2, 31.6 ± 1.2 %) enzymes involved in inflammation process were measured in extracts obtained in the presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation in the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.

Metabolite profiling of violet, white and pink flowers revealing flavonoids composition patterns in Rhododendron pulchrum Sweet

Flower color is the major characteristics and critical breeding program for most Rhododendron species. However, little is known about their coloration mechanism and color inheritance. In this study, petal pigment constituents of three Rhododendron pulchrum Sweet cultivars with different colors were clarified based on LCESI- MS/MS method. Using a broad-targeted metabolomic approach, a total of 149 flavonoids and their glycosylated or methylated derivatives were identified, including 18 anthocyanins (Pg, Cy, Dp, Pn, Pt, and Mv) and 32 flavonols (mainly kaempferol 3-O-glycosides and quercetin 3-O-glycosides). Moreover, anthocyanins were mainly represented by anthocyanidin-3-O-glycosides (glucoside, rutinoside, galactoside, and di-glycosides). Flavone and C-glycosylated flavone were major second metabolites responsible for the difference among three different R. pulchrum cultivars. The accumulation of total flavonoids displayed a clear phenotypic variation: cultivars 'zihe' and 'fenhe' were clustered together, while 'baihe' was clustered alone in the HCA analysis. The composition and content of anthocyanins were more complex in colored flowers ('zehe' and 'fenhe') than in white flower ('baihe'). This study further enhanced our understanding on the flavonoids profile of flower coloration and will provide biochemical basis for further genetic breeding in Rhododendron species.

The influence of monochromatic lights on flavonoid production by the fungus Sanghuangporus vaninii: Modeling of kinetic profiles and expression levels of important genes in flavonoid synthesis

• The kinetic model of the effect of light on flavonoids of fungi was studied. • Kinetic models were combined with the expression levels of related enzymes. • The yield of flavonoids increased by 25.2 % under blue light. • The content of was the highest under blue light. • The expression levels of pal , 4 cl , f3 ' 5 ' h were up-regulated under blue light. Four different monochromatic lights (blue, red, yellow and green) were used to study their separate influence on the growth, morphology and flavonoid accumulation by S. vaninii compared to under white. The results showed that the accumulation rate of total flavonoids under blue light was faster, while the total flavonoid accumulation rate under red light was slower than under white light, and other monochromatic lights had little effect on the synthesis of total flavonoids. The kinetic model parameters and fitting values are basically consistent with the experimental values. Through the development of kinetic model and model validation, the maximum flavonoid concentration under blue light increased by 25.2 % compared with that under white. The relative expression of phenylalanine ammonia lyase (PAL), 4-coumaric acid coenzyme A ligase (4CL) and flavonoid-3′, 5′-hydroxylase (F3′, 5′H) genes were significantly up-regulated under blue light. The influence of lights on the fungal flavonoid production was in part in line with the key genes expression involved.

Growth and chemical profile of clary sage (Salvia sclarea L.) in response to algae and banana peel extracts

BackgroundClary sage (Salvia sclarea L.) has anti-inflammatory and anti-microbial properties; its seeds were imported from Germany for cultivation and acclimatization under the Egyptian environmental conditions as a new source of natural products. Solutions of alga and banana peel waste considered as a source of plant nutrition; it contains some bio-regulators and minerals. This research paper aimed to evaluate growth (fresh and dry weights) and chemical composition (free radical-scavenging activity, carbohydrates, flavonoids, phenols and phenolic compounds) under foliar spray of algae solution (ALS) and the extract of banana peel waste (BPW).ResultsThe highest values of fresh and dry weights were detected with the treatment of 1.5 g/l (BPW) × 1.5 g/l (ALS). The maximum inhibition of free radical -cavenging activity was recorded at 1 g/l (ALS) × 0.5 g/l (BPW). 2 g/l (ALS) without BPW treatment resulted in the greatest amounts of total carbohydrates. The greatest accumulation of total flavonoids was obtained from the plants treated with 0.5 g/l (BPW) × 1 g/l (ALS). Plants exposed to 1.5 g/l (BPW) with 2 g/l (ALS) gave the greatest accumulation of total phenols. Phenolic compounds that were detected by HPLC analysis were changed due to ALS, BPW, and their interactions.ConclusionDifferent variations were observed in growth characters and various chemical constituents of Clary sage under the application of ALS and/or BPW. This research will help farmers to produce medicinal and aromatic plants by using cheap and environmentally friendly methods.

LED Lights Promote Growth and Flavonoid Accumulation of Anoectochilus roxburghii and Are Linked to the Enhanced Expression of Several Related Genes.

Anoectochilus roxburghii is a wild edible species and has been traditionally used for a wide range of diseases in many countries. Our research aims to find the optimal light-emitting diode (LED) lighting conditions to improve the growth and development of A. roxburghii seedling at the acclimation stage. Two-month-old explants were cultured under the various lighting conditions including red (R), blue (B), BR (one blue: four red), BRW151 (one blue: five red: one white), BRW142 (one blue: four red: two white), and fluorescent lamp (FL). The results showed that the lighting conditions not only affect the growth and morphology of plants but also the accumulation of total flavonoids. Single wavelengths (B or R LED) inhibited the growth and secondary biosynthesis of A. roxburghii, while the BR LED showed an enhancement in both growth and biomass accumulation. A. roxburghii plants were grown under BR LED light has average plant height (7.18 cm), stem diameter (17.6mm), number of leaves (5.78 leaves/tree), leaf area (4.67 cm2), fresh weight (0.459 g/tree), dry matter percentages (11.69%), and total flavonoid (1.811 mg/g FW) is considered to be superior to FL lamps and other LEDs in the experiment. This indicates that both blue and red wavelengths are required for the normal growth of A. roxburghii. To learn more about how light affects flavonoid biosynthesis, we evaluated the expression of genes involved in this process (pal, chs, chi, and fls) and found that BR LED light enhances the expression level of chi and fls genes compared to fluorescent lamps (1.18 and 1.21 times, respectively), leading to an increase in the flavonoid content of plant. Therefore, applying BR LED during in vitro propagation of A. roxburghii could be a feasible way to improve the medicinal value of this plant.

Changes in the phenolic compound content and antioxidant activity in developmental maize kernels and expression profiles of phenolic biosynthesis-related genes

Phenolic compounds have various nutritional and functional properties, especially antioxidant activity. The objective of this study was to explore the relationship between the phenolic compound accumulation, antioxidant property and gene expression during maize kernel development. In this study, we explored the effects of developmental stage on the accumulation of phenolic compounds and their antioxidant activities. The expression levels of genes involved in phenolic biosynthesis were also studied. The results showed that the total phenolic content (TPC) and total anthocyanin content (TAC) were gradually increased from 15 to 48 days after pollination (DAP), whereas the total flavonoid content (TFC) decreased continuously. The antioxidant activity of maize kernels was increased gradually and positively associated with TPC. ZmCHSs in flavonoid biosynthetic pathway played important roles for total flavonoid accumulation at both early and later development stages. The expression pattern of ZmANS corresponded to the accumulation of total anthocyanin during kernel development. These results revealed that developmental stage affected the accumulation of different phenolic compounds, antioxidant activity and related gene expression. The antioxidant activity of maize kernels was dependent on the total phenolic accumulation which was related to the expression profiles of the genes participated in phenolic synthesis.

Salt-tolerance identification and quality evaluation of Abelmoschus manihot (L.) Medik

Abelmoschus manihot (L.) Medik. is a medicinal and edible plant. To evaluate its suitability for cultivation on the coastal saline-alkali land in northern China for high quality functional products, salt-tolerance identification and flavonoid contents were evaluated under saline treatments. Results showed that the salt-tolerance threshold of A. manihot ranged from 4.1 to 6.9 g L−1; however, low soil salt content (<3 g L−1) had the best growth and accumulation of total flavonoids. Sixteen kinds of common functional components such as hyperoside, rutoside, and quercetin were found. Of these components, the four (myricetin-3-0-glucoside, rutoside, quercetin-3′-0-glucoside, and gossypetin-8-0-β-d-glucuronic acid) with the highest content were chosen as the quality evaluation indexes. High levels of quality and yield occurred at a soil salt content of 3 g L−1. Our results suggested that soil salt content should not exceed 3 g L−1 in field cultivation for high quality and high yield of A. manihot.