Transcriptome analysis and metabolic profiling of green and red kale (Brassica oleracea var. acephala) seedlings

Bioinformatics analysis of gene bhsA and its role in Ca2+ -treated Escherichia coli

One of the commonly employed methods in molecular biology is to utilize calcium chloride to treat Escherichia coli for the preparation of competent cells to facilitate foreign gene expression. However, the molecular mechanisms underlying Ca2+ mediation of competent cell formation and identification of the key genes involved in the process remain unclear. In previous studies, the combined analysis of transcriptomics and proteomics revealed bhsA as one of the crucial genes. The gene ontology functional annotation of bhsA identified it as a member of the YhcN family encoding an outer membrane protein that confers resistance to various stresses. The IPR0108542 domain found within the protein plays a significant role in stress response and biofilm formation in E. coli. Analysis of the STRING database showed that the proteins interacting with bhsA are primarily involved in biofilm formation and stress resistance. Using the RED homologous recombination method, a bhsA deletion strain was constructed to verify its role in E. coli genetic transformation. Although the mutant strain showed no significant differences in morphology or growth trend when compared to the wild-type strain, its transformation efficiency decreased by 1.14- and 1.64-fold with plasmids pUC19 and pET-32a. Furthermore, the 1-N-phenylnaphthylamine assay indicated a 1.71-fold reduction in cell membrane permeability in the mutant strain.

Systemic biochemical changes in pepper (Capsicum annuum L.) against Rhizoctonia solani by kale (Brassica oleracea var. acephala L.) green manure application

BACKGROUND

In the search for new alternatives to avoid the problems associated with the use of synthetic chemical fungicides in agriculture, the use of green manure (GrM) could help combat fungal diseases of crops, such as those produced by the necrotrophic pathogen Rhizoctonia solani. In the case of the use of Brassica tissues as GrM, it could have an elicitor capacity for systemic plant resistance.

RESULTS

We used kale leaves as a GrM and applied it to pepper plants infected with R. solani. The application of freeze-dried kale tissues to the roots of pepper plants produced a systemic activation of foliar defences via the salicylic acid (SA) and ethylene (ET) pathways, significantly reducing pathogen damage. In addition, this systemic response led to the accumulation of secondary defence metabolites, such as pipecolic acid, hydroxycoumarin and gluconic acid, in leaves. Remarkably, pepper plants treated with lyophilised kale GrM accumulated glucosinolates when infected with R. solani. We also confirmed that autoclaving removed part of the glucobrassicin (85%) and sinigrin (19%) content of the kale tissues.

CONCLUSIONS

GrM kale tissues can activate systemic defences in bell pepper against foliar pathogens through SA/ET hormonal pathways, accumulating secondary defence metabolites.

Metabolic and Transcriptomic Analyses Reveal Different Metabolite Biosynthesis Profiles between Purple and Green Pak Choi

Pak choi is one of the most important leafy vegetables planted in East Asia and provides essential nutrients for the human body. Purple pak choi differs mainly in leaf colour but exhibits distinct nutritional profiles from green pak choi. In this study, we performed metabolic and transcriptomic analyses to uncover the mechanisms underlying the differences in metabolite biosynthesis profiles between the two pak choi varieties. Metabolite profiling revealed significant differences in the levels of metabolites, mainly amino acids and their derivatives and flavonoids. Furthermore, 34 flavonoids significantly differed between green and purple pak choi leaves, and cyanidin and its derivative anthocyanins were abundant in purple pak choi. In addition, we found that the structural genes CHS, DFR, ANS, and UGT75C1, as well as the transcription factor MYB2, play a major role in anthocyanin synthesis. These results provide insight into the molecular mechanisms underlying leaf pigmentation in pak choi and offer a platform for assessing related varieties.

Vegetable as a Source of Bioactive Compounds with Photoprotective Properties: Implication in the Aging Process

The skin, as an external organ, protects the entire body against harmful external factors. One of these factors is ultraviolet (UV) radiation, which in excessive amounts can lead to premature skin aging, DNA damage, and even skin cancer. Therefore, it is worth supporting skin protection not only with commercially available preparations, but also with a proper diet. Consuming certain vegetables and applying them topically may reduce the effects of UV radiation. The aim of the review was to collect information on the effects of vegetables and their compounds on the skin when used externally or included in the diet. This review summarizes studies on vegetables, such as broccoli, cucumber, kale, tomato, and carrot, which have shown significant activity in skin photoprotection. Additionally, it outlines the bioactive substances present in these vegetables and their effects.

Systems-level proteomics and metabolomics reveals the diel molecular landscape of diverse kale cultivars

Kale is a group of diverse Brassicaceae species that are nutritious leafy greens consumed for their abundance of vitamins and micronutrients. Typified by their curly, serrated and/or wavy leaves, kale varieties have been primarily defined based on their leaf morphology and geographic origin, despite having complex genetic backgrounds. Kale is a very promising crop for vertical farming due to its high nutritional content; however, being a non-model organism, foundational, systems-level analyses of kale are lacking. Previous studies in kale have shown that time-of-day harvesting can affect its nutritional composition. Therefore, to gain a systems-level diel understanding of kale across its wide-ranging and diverse genetic landscape, we selected nine publicly available and commercially grown kale cultivars for growth under near-sunlight LED light conditions ideal for vertical farming. We then analyzed changes in morphology, growth and nutrition using a combination of plant phenotyping, proteomics and metabolomics. As the diel molecular activities of plants drive their daily growth and development, ultimately determining their productivity as a crop, we harvested kale leaf tissue at both end-of-day (ED) and end-of-night (EN) time-points for all molecular analyses. Our results reveal that diel proteome and metabolome signatures divide the selected kale cultivars into two groups defined by their amino acid and sugar content, along with significant proteome differences involving carbon and nitrogen metabolism, mRNA splicing, protein translation and light harvesting. Together, our multi-cultivar, multi-omic analysis provides new insights into the molecular underpinnings of the diel growth and development landscape of kale, advancing our fundamental understanding of this nutritious leafy green super-food for horticulture/vertical farming applications.

Investigation of the Key Genes Associated with Anthocyanin Accumulation during Inner Leaf Reddening in Ornamental Kale (Brassica oleracea L. var. acephala)

Ornamental kale (Brassica oleracea L. var. acephala) is a popular decorative plant in late autumn and winter. However, only during low-temperature color-changed periods below rough 15 °C can the plant accumulate anthocyanins and exhibit a diverse array of foliar color patterns. In this study, we probed into the potential mechanism of inner leaf reddening in a red-leaf pure line of ornamental kale by physiological, metabolic, and transcriptomic analyses. Determination of anthocyanin contents in the uncolored new white leaves (S0), the light red leaves (S1) in the reddening period and the red leaves (S2) completing color change, and analysis of anthocyanin metabolites at stage S2, revealed that the coloring of red leaves was mainly attributed to the accumulation of cyanidins. We further used transcriptomic sequencing between the pairwise S0, S1, and S2 stages to identify 21 differentially expressed genes (DEGs) involved in anthocyanin biosynthesis, among which the expression level of 14 DEGs was positively correlated with anthocyanin accumulation, and 6 DEGs were negatively correlated with anthocyanin accumulation. A total of 89 co-expressed genes were screened out, from which three DEGs (BoCHI, Bo4CL3, and BoF3H) were identified as hub genes in co-expression DEGs network. BoDFR and BoCHI were the DEGs with the highest expressions at S2. Moreover, two co-expressed DEGs related to stress response (BoBBX17 and BoCOR47) also exhibited upregulated expressions and positive correlations with anthocyanin accumulation. A deep dive into the underlying regulatory network of anthocyanin accumulation comprising these six upregulated DEGs from S0 to S2 was performed via trend, correlation, and differentially co-expression analysis. This study uncovered the DEGs expression profiles associated with anthocyanin accumulation during ornamental kale inner leaf reddening, which provided a basis for further dissecting the molecular mechanisms of leaf color characteristic change in ornamental kale at low temperatures.

Bioactive Compounds from Leaf Vegetables as Preservatives

Trends toward a healthier diet are increasing attention to clean-label products. This has led to the search for new ingredients that avoid the use of chemical additives. Food industries are responding to these demands by incorporating natural preservatives into their products, which consumers perceive as healthy. Leafy vegetables would fit this strategy since they are common components of the diet and are associated with beneficial health effects. The objective of this chapter is to offer an overview of the large number of bioactive compounds (phenolic acids, flavonoids, anthocyanins, glucosinolates, and sulfur compounds) present in these plants, which would be responsible for their activity as potential preservatives. Its incorporation into food would improve the quality and extend the shelf life by reducing oxidative processes and inhibiting or retarding the microbial growth that occurs during processing and storage without reducing the organoleptic characteristics of the product.

Effects of preharvest factors on antidiabetic potential of some foods and herbal plants

Diabetes is a metabolic disorder with no definite treatment, but it can be controlled by changing lifestyle and diet. Consumption of high-fiber and nutrient-rich foods including vegetables have been shown to reduce risks of obesity and Type II Diabetes Mellitus (T2DM). Also, many herbal plants have been associated with reduced risks of T2DM because of their composition of secondary metabolites. Antioxidant activities of some secondary metabolites have potent inhibitory effects against inflammation linked with insulin resistance and oxidative stress. More than 800 known medicinal plants are used to control diabetes and its relevant complications. However, variations in preharvest factors including plant genotype, growing medium properties, climatic factors, and management practices can influence plant growth and their accumulation of phytochemicals with health-promoting properties. However, the effects of these preharvest factors on the antidiabetic properties of plant secondary metabolites are neither explicit nor easily accessible in the literature. Therefore, this review aims to document recent studies that reported on under-exploited medicinal plants with antidiabetic properties. We reviewed several important preharvest factors that can potentially affect the synthesis of phytoconstituents which possess antidiabetic properties. This review will help identify gaps for future research in phytomedicine and functional foods.

Fine Mapping of BoVl Conferring the Variegated Leaf in Ornamental Kale (Brassica oleracea var. acephala)

Ornamental kale, as a burgeoning landscaping plant, is gaining popularity for its rich color patterns in leaf and cold tolerance. Leaf variegation endows ornamental kale with unique ornamental characters, and the mutants are ideal materials for exploring the formation mechanisms of variegated phenotype. Herein, we identified a novel variegated leaf kale mutant ‘JC007-2B’ with green margins and white centers. Morphological observations and physiological determinations of the green leaf stage (S1), albino stage (S2) and variegated leaf stage (S3) demonstrated that the chloroplast structure and photosynthetic pigment content in the white sectors (S3_C) of variegated leaves were abnormal. Genetic analysis revealed that a single dominant nuclear gene (BoVl) controlled the variegated leaf trait of ‘JC007-2B’, and three candidate genes for BoVl were fine-mapped to a 6.74 Kb interval on chromosome C03. Multiple sequence alignment among the green-leaf mapping parent ‘BS’, recombinant individuals, mutant parent ‘JC007-2B’ and its same originated DH line population established that the mutation sites in Bo3g002080 exhibited a complete consensus. Bo3g002080, homologous to Arabidopsis MED4, was identified as the candidate gene for BoVl. Expression analysis showed that Bo3g002080 displayed a 2158.85-fold higher expression at albino stage than that in green leaf stage. Transcriptome analysis showed that related pathways of photosynthesis and chloroplast development were significantly enriched in the white sectors, and relevant DEGs involved in these pathways were almost down-regulated. Overall, our study provides a new gene resource for cultivar breeding in ornamental kale and contributes to uncovering the molecular genetic mechanism underlying the variegated leaf formation.

Extraction of Bioactive Compounds from Different Vegetable Sprouts and Their Potential Role in the Formulation of Functional Foods against Various Disorders: A Literature-Based Review

In this review, we discuss the advantages of vegetable sprouts in the development of food products as well as their beneficial effects on a variety of disorders. Sprouts are obtained from different types of plants and seeds and various types of leafy, root, and shoot vegetables. Vegetable sprouts are enriched in bioactive compounds, including polyphenols, antioxidants, and vitamins. Currently, different conventional methods and advanced technologies are used to extract bioactive compounds from vegetable sprouts. Due to some issues in traditional methods, increasingly, the trend is to use recent technologies because the results are better. Applications of phytonutrients extracted from sprouts are finding increased utility for food processing and shelf-life enhancement. Vegetable sprouts are being used in the preparation of different functional food products such as juices, bread, and biscuits. Previous research has shown that vegetable sprouts can help to fight a variety of chronic diseases such as cancer and diabetes. Furthermore, in the future, more research is needed that explores the extraordinary ways in which vegetable sprouts can be incorporated into green-food processing and preservation for the purpose of enhancing shelf-life and the formation of functional meat products and substitutes.

Identification of Key Genes during Ca2+-Induced Genetic Transformation in Escherichia coli by Combining Multi-Omics and Gene Knockout Techniques

The molecular mechanism of the Ca²⁺-mediated formation of competent cells in Escherichia coli remains unclear. In this study, transcriptome and proteomics techniques were used to screen genes in response to Ca²⁺ treatment. A total of 333 differentially expressed genes (317 upregulated and 16 downregulated) and 145 differentially expressed proteins (54 upregulated and 91 downregulated) were obtained. These genes and proteins are mainly enriched in cell membrane components, transmembrane transport, and stress response-related functional terms. Fifteen genes with these functions, including yiaW, ygiZ, and osmB, are speculated to play a key role in the cellular response to Ca²⁺. Three single-gene deletion strains were constructed with the Red homologous recombination method to verify its function in genetic transformation. The transformation efficiencies of yiaW, ygiZ, and osmB deletion strains for different-size plasmids were significantly increased. None of the three gene deletion strains changed in size, which is one of the main elements of microscopic morphology, but they exhibited different membrane permeabilities and transformation efficiencies. This study demonstrates that Ca²⁺-mediated competence formation in E. coli is not a simple physicochemical process and may involve the regulation of genes in response to Ca²⁺. This study lays the foundation for further in-depth analyses of the molecular mechanism of Ca²⁺-mediated transformation. IMPORTANCE Using transcriptome and proteome techniques and association analysis, we identified several key genes involved in the formation of Ca²⁺-mediated E. coli DH5α competent cells. We used Red homologous recombination technology to construct three single-gene deletion strains and found that the transformation efficiencies of yiaW, ygiZ, and osmB deletion strains for different-size plasmids were significantly increased. These results proved that the genetic transformation process is not only a physicochemical process but also a reaction process involving multiple genes. These results suggest ways to improve the horizontal gene transfer mechanism of foodborne microorganisms and provide new ideas for ensuring the safety of food preservation and processing.

Extracellular vesicles derived from microgreens of Raphanus sativus L. var. caudatus Alef contain bioactive macromolecules and inhibit HCT116 cells proliferation

Extracellular vesicles (EVs) are phospholipid bilayer vesicles released from cells, containing natural cargos. Microgreens of Raphanus sativus L. var. caudatus Alef were used in this study as the source of EVs. EVs were isolated by differential centrifugation. The physical properties were determined by dynamic light scattering (DLS) and electron microscopy. The biological and chemical composition were studied by Fourier-transform infrared (FTIR) microspectroscopy and high-performance liquid chromatography analysis, respectively. EVs had a median size of 227.17 and 234.90 ± 23.30 nm determined by electron microscopy and DLS, respectively with a polydispersity index of 0.293 ± 0.019. Electron microscopy indicated the intact morphology and confirmed the size. The FTIR spectra revealed that EVs are composed of proteins as the most abundant macromolecules. Using a curve-fitting analysis, β-pleated sheets were the predominant secondary structure. Notably, the micromolecular biomarkers were not detected. EVs exerted anti-cancer activity on HCT116 colon cancer over Vero normal cells with an IC₅₀ of 448.98 µg/ml and a selectivity index of > 2.23. To conclude, EVs could be successfully prepared with a simple and effective isolation method to contain nano-sized macromolecules possessing anti-cancer activity.

Glucosinolates and Biotic Stress Tolerance in Brassicaceae with Emphasis on Cabbage: A Review

Glucosinolates (GSLs) and GSL-associated genes are receiving increasing attention from molecular biologists due to their multifunctional properties. GSLs are secondary metabolites considered to be highly active in most Brassica species. Their importance has motivated the discovery and functional analysis of the GSLs and GSL hydrolysis products involved in disease development in brassicas and other plants. Comprehensive knowledge of the GSL content of Brassica species and the molecular details of GSL-related genes will help elucidate the molecular control of this plant defense system. This report provides an overview of the current status of knowledge on GSLs, GSL biosynthesis, as well as hydrolysis related genes, and GSL hydrolysis products that regulate fungal, bacterial, and insect resistance in cabbage and other brassicas.

Anthocyanins identification and transcriptional regulation of anthocyanin biosynthesis in purple Brassica napus

The main anthocyanin components were identified, and the transcriptional regulation pattern of anthocyanin related genes in leaves and stem bark was elucidated in a purple B. napus. Brassica napus is one of the most important oil crops planted worldwide, and developing varieties of dual-purpose for oil and vegetable is beneficial to improve economic benefits. Anthocyanins are a class of secondary metabolites that not only make plants present beautiful colors, but have a variety of important physiological functions and biological activities. Therefore, increasing the accumulation of anthocyanin in vegetative organs can improve vegetable value of rapeseed. However, anthocyanin enriched varieties in vegetative organs are rare, and there are few studies on category identification and accumulation mechanism of anthocyanin, which limits the utilization of anthocyanins in B. napus. In this study, 157 anthocyanin biosynthesis related genes (ABGs) were identified in B. napus genome by homology comparison and collinearity analysis of genes related to anthocyanin synthesis and regulation in Arabidopsis. Moreover, five anthocyanins were identified in the stem bark and leaves of the purple B. napus PR01 by high performance liquid chromatography-mass spectrometry (HPLC-MS), and the expression characteristics of ABGs in the leaves and stem bark of PR01 were analyzed and compared with the green cultivar ZS11 by RNA-Seq. Combining further weighted gene co-expression network analysis (WGCNA), the up-regulation of transcript factors BnaA07. PAP2 and BnaC06. PAP2 were identified as the key to the up-regulation of most of anthocyanin synthesis genes that promoted anthocyanin accumulation in PR01. This study is helpful to understand the transcriptional regulation of anthocyanin biosynthesis in B. napus and provides the theoretical basis for breeding novel varieties of dual-purpose for oil and vegetable.

Isolation of bioactive peptides and multiple nutraceuticals of antidiabetic and antioxidant functionalities through sprouting: Recent advances

The employment of proteases directly from enzymes or indirectly from microorganisms during fermentation for the purpose of proteolysis of food proteins has been the conventional trend for the derivation of bioactive peptides from food matrices. However, recent studies have shown that inherent protease enzymes can be activated for this activity for vegetable foods using the sprouting process. The benefits of ease of operation, and reduced processing costs are formidable advantages for the optimal consideration of this technique. On another note, the demand for functional foods with therapeutic health effects has increased in recent years. Globally, plant foods are perceived as dietetic choices bearing sufficient quantities of concomitant nutraceuticals. In this manuscript, the sprouting route for the isolation of peptides and glucosinolates, and for the enhancement of total phenolic contents, polyunsaturated fatty acid profiles, and other bioactive constituents was explored. Advances regarding the phytochemical transformations in the course of sprouting, the therapeutic functionalities, and microbiological safety concerns of vegetable sprouts are delineated. In addition, consumption of vegetable sprouts has been shown to be more efficient in supplying nutraceutical components relative to their unsprouted counterparts. Biochemical mechanisms involving the inhibition of digestive enzymes such as α-amylase, β-glucosidase, and dipeptidyl peptidase IV (DPP-IV), single electron transfer, and metal chelation, for impartation of health benefits, have been reported to occur from bioactive components isolated from vegetable sprouts. PRACTICAL APPLICATIONS: Sprouting initiates proteolysis of vegetable proteins for the release of bioactive peptides. Abiotic stresses can be used as elicitors during the sprouting process to achieve enhanced phytochemical profiles of sprouts. Sprouting is a relatively more convenient approach to the improvement of the health benefits of vegetable foods. Vegetable sprouts are potential for the management of metabolic syndrome disorders.

Anti-Inflammatory, Antioxidant, and Skin Regenerative Potential of Secondary Metabolites from Plants of the Brassicaceae Family: A Systematic Review of In Vitro and In Vivo Preclinical Evidence (Biological Activities Brassicaceae Skin Diseases)

The Brassicaceae family constitutes some of the most well-studied natural products in the world, due to their anti-inflammatory, anti-oxidative, and pro-regenerative properties as well as their ubiquitous distribution across the world. To evaluate the potential efficacy of the Brassicaceae family in the treatment of inflammatory skin disorders and wounds, based on preclinical evidence from in vivo and in vitro studies. This systematic review was performed according to the PRISMA guidelines, using a structured search on the PubMed-Medline, Scopus, and Web of Science platforms. The studies included were those that used murine models and in vitro studies to investigate the effect of Brassicaceae on skin disorders. Bias analysis and methodological quality assessments were examined through SYRCLE's RoB tool. Brassicaceae have shown positive impacts on inflammatory regulation of the skin, accelerating the wound healing process, and inhibiting the development of edema. The studies showed that the Brassicaceae family has antioxidant activity and effects on the modulation of cyclooxygenase 2 and the nuclear factor kappa β (NFκβ) pathway. The secondary metabolites present in Brassicas are polyphenols (68.75%; n = 11), terpenes/carotenoids (31.25%; n = 5), and glycosylates (25%; n = 4), which are responsible for their anti-inflammatory, healing, and antioxidant effects. In addition, the current evidence is reliable because the bias analysis showed a low risk of bias. Our review indicates that compounds derived from Brassicaceae present exceptional potential to treat inflammatory skin diseases and accelerate cutaneous wound healing. We hope that our critical analysis can help to expedite clinical research and to reduce methodological bias, thereby improving the quality of evidence in future research. The registration number on the Prospero platform is CRD42021262953.

Dietary polyglycosylated anthocyanins, the smart option? A comprehensive review on their health benefits and technological applications

Over the years, anthocyanins have emerged as one of the most enthralling groups of natural phenolic compounds and more than 700 distinct structures have already been identified, illustrating the exceptional variety spread in nature. The interest raised around anthocyanins goes way beyond their visually appealing colors and their acknowledged structural and biological properties have fueled intensive research toward their application in different contexts. However, the high susceptibility of monoglycosylated anthocyanins to degradation under certain external conditions might compromise their application. In that regard, polyglycosylated anthocyanins (PGA) might offer an alternative to overcome this issue, owing to their peculiar structure and consequent less predisposition to degradation. The most recent scientific and technological findings concerning PGA and their food sources are thoroughly described and discussed in this comprehensive review. Different issues, including their physical-chemical characteristics, consumption, bioavailability, and biological relevance in the context of different pathologies, are covered in detail, along with the most relevant prospective technological applications. Due to their complex structure and acyl groups, most of the PGA exhibit an overall higher stability than the monoglycosylated ones. Their versatility allows them to act in a wide range of pathologies, either by acting directly in molecular pathways or by modulating the disease environment attributing an added value to their food sources. Their recent usage for technological applications has also been particularly successful in different industry fields including food and smart packaging or in solar energy production systems. Altogether, this review aims to put into perspective the current state and future research on PGA and their food sources.

Metabolic and transcriptome analysis of dark red taproot in radish (Raphanus sativus L.)

The red color in radish taproots is an important quality index and is mainly affected by anthocyanins. However, the metabolite components and gene expression underlying dark red taproot color formation in radish remain elusive. In this study, the metabolites and gene expression patterns affecting anthocyanin biosynthesis were monitored in the dark red taproots. Comparative analysis of anthocyanin metabolites between dark red taproots and white taproots indicated that pelargonin and pelargonidin 3-O-beta-D-glucoside were the most promising dark red pigments responsible for the coloration of the taproots. Transcriptomic analysis of gene expression between dark red taproots and white taproots revealed that most of genes involved in the anthocyanin biosynthesis pathway were up-regulated in dark red taproots. In particular, RsCHS and RsDFR were the two most up-regulated genes in the dark red taproots. Moreover, the higher coexpression of two R2R3-Myb transcription factors, RsMYB1 and RsMYB2, may contribute to dark red color formation. Our work documents metabolomic and transcriptomic changes related to the dark red color formation in taproots radish and provides valuable data for anthocyanin-rich radish breeding.

Transcriptome Analysis of Green and White Leaf Ornamental Kale Reveals Coloration-Related Genes and Pathways

Leaf color is a crucial agronomic trait in ornamental kale. However, the molecular mechanism regulating leaf pigmentation patterns in green and white ornamental kale is not completely understood. To address this, we performed transcriptome and pigment content analyses of green and white kale leaf tissues. A total of 5,404 and 3,605 different expressed genes (DEGs) were identified in the green vs. white leaf and the green margin vs. white center samples. Kyoto Encyclopedia of Genes and Genome (KEGG) pathway enrichment analysis showed that 24 and 15 common DEGs in two pairwise comparisons were involved in chlorophyll metabolism and carotenoid biosynthesis, respectively. Seventeen genes related to chlorophyll biosynthesis were significantly upregulated in green leaf tissue, especially chlH and por. Of the 15 carotenoid biosynthesis genes, all except CYP707A and BG1 were lower expressed in white leaf tissue. Green leaf tissue exhibited higher levels of chlorophyll and carotenoids than white leaf tissue. In addition, the DEGs involved in photosystem and chlorophyll-binding proteins had higher expression in green leaf tissue. The PSBQ, LHCB1.3, LHCB2.4, and HSP70 may be key genes of photosynthesis and chloroplast formation. These results demonstrated that green and white coloration in ornamental kale leaves was caused by the combined effects of chlorophyll and carotenoid biosynthesis, chloroplast development, as well as photosynthesis. These findings enhance our understanding of the molecular mechanisms underlying leaf color development in ornamental kale.

High hydrostatic pressure treatment induced microstructure changes and isothiocyanates biosynthesis in kale

Effects of high-pressure processing (HPP) on the myrosinase activity, glucosinolate (GLS) content, isothiocyanate (ITC) conversion rate, color, and bacterial count of kale leaves were investigated. Thermal process at 100 °C were used as negative control groups. The sample processed at 600 MPa exhibited the highest myrosinase activity and ITC conversion rate of 70.4%, while the GLS content was significantly lower than those in the raw and the thermally processed samples. However, processing of the samples at elevated temperatures results in gradual loss of myrosinase activity. SEM images showed that HPP induces irregular crushing damage to the veins, edges, and surfaces of the leaves, thereby promoting the conversion process in the myrosinase-GLS-ITC system. Additionally, HPP caused less significant color change of the kale leaves than thermal treatment. HPP achieved the same level of pasteurization as thermal treatment in terms of bacterial count.

Low Temperatures Affect the Physiological Status and Phytochemical Content of Flat Leaf Kale (Brassica oleracea var. acephala) Sprouts

Consumption of plants in the juvenile stage becomes popular because sprouts are easy to grow, and they can be a tasty source of micro- and macro-nutrients and various phytochemicals. However, some environmental factors during sprout growth can affect their characteristics. In this article, we investigated how low temperatures during cultivation (8 °C) and additional exposure to freezing temperatures (−8 °C) affect the physiological status and phytochemical content of kale (Brassica oleracea var. acephala) sprouts compared to the control grown at 21 °C. We conducted five independent laboratory experiments and found that low temperature significantly increased proline content and decreased sprouts yield. In addition, low temperature caused a significant decrease in carotenoid and flavonoid content, while phenolic acid content and total glucosinolates content increased, but individual glucosinolates were differentially affected. Our results indicate that low temperatures affect the physiological status of kale sprouts and affect the content of phytochemicals.

Improving the Health-Benefits of Kales (Brassica oleracea L. var. acephala DC) through the Application of Controlled Abiotic Stresses: A Review

Kale (Brassica oleracea L. var. acephala DC) is a popular cruciferous vegetable originating from Central Asia, and is well known for its abundant bioactive compounds. This review discusses the main kale phytochemicals and emphasizes molecules of nutraceutical interest, including phenolics, carotenoids, and glucosinolates. The preventive and therapeutic properties of kale against chronic and degenerative diseases are highlighted according to the most recent in vitro, in vivo, and clinical studies reported. Likewise, it is well known that the application of controlled abiotic stresses can be used as an effective tool to increase the content of phytochemicals with health-promoting properties. In this context, the effect of different abiotic stresses (saline, exogenous phytohormones, drought, temperature, and radiation) on the accumulation of secondary metabolites in kale is also presented. The information reviewed in this article can be used as a starting point to further validate through bioassays the effects of abiotically stressed kale on the prevention and treatment of chronic and degenerative diseases.

Kale supplementation during high fat feeding improves metabolic health in a mouse model of obesity and insulin resistance

Cruciferous vegetables have been widely studied for cancer prevention and cardiovascular health. Broccoli is the cruciferous vegetable whose phytochemistry and physiological effects have been most extensively studied. Kale (Brassica oleracea var. acephala) appears on lists of 'healthiest, nutrient dense foods' but, there is paucity of data on kale as a functional food. In a 12-week study, we tested the effect of curly green kale on high fat diet (HFD) induced obesity and insulin resistance, lipid metabolism, endotoxemia and inflammation in C57BL/6J mice fed isocaloric diets. Kale supplementation did not attenuate HFD diet induced fat accumulation and insulin resistance (P = ns; n = 9) but, it lowered serum triglycerides, low density lipoprotein (LPL) cholesterol and prevented HFD induced increases in systemic endotoxemia and inflammation (serum LPS and Ccl2) (P<0.01; n = 9). In adipose tissue, kale enhanced the expression of genes involved in adipogenesis (P<0.01; n = 9), reduced the appearance of histologic markers of inflammation, downregulated both the gene expression and protein expression of the adipose tissue specific inflammation markers CD11c and F4/80 (P<0.001; n = 9) and reduced the gene expression of a battery of chemokine C-C motif ligands (Ccl2, Ccl6, Ccl7, Ccl8, Ccl9) and chemokine C-C motif receptors (Ccr2, Ccr3, Ccr5). We conclude that kale vegetable protects against HFD diet induced dysfunction through mechanisms involving lipid metabolism, endotoxemia and inflammation.

Metabolite Profiling and Transcriptome Analysis Provide Insight into Seed Coat Color in Brassica juncea

The allotetraploid species Brassica juncea (mustard) is grown worldwide as oilseed and vegetable crops; the yellow seed-color trait is particularly important for oilseed crops. Here, to examine the factors affecting seed coat color, we performed a metabolic and transcriptomic analysis of yellow- and dark-seeded B. juncea seeds. In this study, we identified 236 compounds, including 31 phenolic acids, 47 flavonoids, 17 glucosinolates, 38 lipids, 69 other hydroxycinnamic acid compounds, and 34 novel unknown compounds. Of these, 36 compounds (especially epicatechin and its derivatives) accumulated significantly different levels during the development of yellow- and dark-seeded B. juncea. In addition, the transcript levels of BjuDFR, BjuANS,BjuBAN, BjuTT8, and BjuTT19 were closely associated with changes to epicatechin and its derivatives during seed development, implicating this pathway in the seed coat color determinant in B. juncea. Furthermore, we found numerous variations of sequences in the TT8A genes that may be associated with the stability of seed coat color in B. rapa, B. napus, and B. juncea, which might have undergone functional differentiation during polyploidization in the Brassica species. The results provide valuable information for understanding the accumulation of metabolites in the seed coat color of B. juncea and lay a foundation for exploring the underlying mechanism.

Effects of Temperature, Relative Humidity, and Carbon Dioxide Concentration on Growth and Glucosinolate Content of Kale Grown in a Plant Factory

The growth of plants and their glucosinolate content largely depend on the cultivation environment; however, there are limited reports on the optimization of ambient environmental factors for kale grown in plant factories. This study was conducted to investigate the effects of temperature, relative humidity, and the carbon dioxide (CO₂) concentration on kale growth and glucosinolate content in different growth stages of cultivation in a plant factory. Kale was grown under different temperatures (14, 17, 20, 23, and 26 °C), relative humidities (45, 55, 65, 75, and 85%), and CO₂ concentrations (400, 700, 1000, 1300, and 1600 ppm) in a plant factory. Two and four weeks after transplantation, leaf samples were collected to evaluate the physical growth and glucosinolate contents. The statistical significance of the treatment effects was determined by two-way analysis of variance, and Duncan’s multiple range test was used to compare the means. A correlation matrix was constructed to show possible linear trends among the dependent variables. The observed optimal temperature, relative humidity, and CO₂ range for growth (20–23 °C, 85%, and 700–1000 ppm) and total glucosinolate content (14–17 °C, 55–75%, and 1300–1600 ppm) were different. Furthermore, the glucosinolate content in kale decreased with the increase of temperature and relative humidity levels, and increased with the increase of CO₂ concentration. Most of the physical growth variables showed strong positive correlations with each other but negative correlations with glucosinolate components. The findings of this study could be used by growers to maintain optimum environmental conditions for the better growth and production of glucosinolate-rich kale leaves in protected cultivation facilities.

Unveiling the shade nature of cyanic leaves: A view from the "blue absorbing side" of anthocyanins

Anthocyanins have long been suggested as having great potential in offering photoprotection to plants facing high light irradiance. Nonetheless, their effective ability in protecting the photosynthetic apparatus from supernumerary photons has been questioned by some authors, based upon the inexact belief that anthocyanins almost exclusively absorb green photons, which are poorly absorbed by chlorophylls. Here we focus on the blue light absorbing features of anthocyanins, a neglected issue in anthocyanin research. Anthocyanins effectively absorb blue photons: the absorbance of blue relative to green photons increases from tri- to mono-hydroxy B-ring substituted structures, reaching up to 50% of green photons absorption. We offer a comprehensive picture of the molecular events activated by low blue-light availability, extending our previous analysis in purple and green basil, which we suggest to be responsible for the "shade syndrome" displayed by cyanic leaves. While purple leaves display overexpression of genes promoting chlorophyll biosynthesis and light harvesting, in green leaves it is the genes involved in the stability/repair of photosystems that are largely overexpressed. As a corollary, this adds further support to the view of an effective photoprotective role of anthocyanins. We discuss the profound morpho-anatomical adjustments imposed by the epidermal anthocyanin shield, which reflect adjustments in light harvesting capacity under imposed shade and make complex the analysis of the photosynthetic performance of cyanic versus acyanic leaves.

Estimation of Glucosinolates and Anthocyanins in Kale Leaves Grown in a Plant Factory Using Spectral Reflectance

The spectral reflectance technique for the quantification of the functional components was applied in different studies for different crops, but related research on kale leaves is limited. This study was conducted to estimate the glucosinolate and anthocyanin components of kale leaves cultivated in a plant factory based on diffuse reflectance spectroscopy through regression methods. Kale was grown in a plant factory under different treatments. After specific periods of transplantation, leaf samples were collected, and reflectance spectra were measured immediately from nine different points on each leaf. The same leaf samples were freeze-dried and stored for analysis of the functional components. Regression procedures, such as principal component regression (PCR), partial least squares regression (PLSR), and stepwise multiple linear regression (SMLR), were applied to relate the functional components with the spectral data. In the laboratory analysis, progoitrin and glucobrassicin, as well as cyanidin and malvidin, were found to be dominating components in glucosinolates and anthocyanins, respectively. From the overall analysis, the SMLR model showed better performance, and the identified wavelengths for estimating the glucosinolates and anthocyanins were in the early near-infrared (NIR) region. Specifically, reflectance at 742, 761, 787, 796, 805, 833, 855, 932, 947, and 1000 nm showed a strong correlation.

Dynamic Changes of the Anthocyanin Biosynthesis Mechanism During the Development of Heading Chinese Cabbage (Brassica rapa L.) and Arabidopsis Under the Control of BrMYB2

Chinese cabbage is an important vegetable mainly planted in Asian countries, and mining the molecular mechanism responsible for purple coloration in Brassica crops is fast becoming a research hotspot. In particular, the anthocyanin accumulation characteristic of purple heading Chinese cabbage, along with the plant's growth and head developing, is still largely unknown. To elucidate the dynamic anthocyanin biosynthesis mechanism of Chinese cabbage during its development processes, here we investigated the expression profiles of 86 anthocyanin biosynthesis genes and corresponding anthocyanin accumulation characteristics of plants as they grew and their heads developed, between purple heading Chinese cabbage 11S91 and its breeding parents. Anthocyanin accumulation of 11S91 increased from the early head formation period onward, whereas the purple trait donor 95T2-5 constantly accumulated anthocyanin throughout its whole plant development. Increasing expression levels of BrMYB2 and BrTT8 together with the downregulation of BrMYBL2.1, BrMYBL2.2, and BrLBD39.1 occurred in both 11S91 and 95T2-5 plants during their growth, accompanied by the significantly continuous upregulation of a phenylpropanoid metabolic gene, BrPAL3.1; a series of early biosynthesis genes, such as BrCHSs, BrCHIs, BrF3Hs, and BrF3'H; as well as some key late biosynthesis genes, such as BrDFR1, BrANS1, BrUF3GT2, BrUF5GT, Br5MAT, and Brp-Cout; in addition to the transport genes BrGST1 and BrGST2. Dynamic expression profiles of these upregulated genes correlated well with the total anthocyanin contents during the processes of plant growth and leaf head development, and results supported by similar evidence for structural genes were also found in the BrMYB2 transgenic Arabidopsis. After intersubspecific hybridization breeding, the purple interior heading leaves of 11S91 inherited the partial purple phenotypes from 95T2-5 while the phenotypes of seedlings and heads were mainly acquired from white 94S17; comparatively in expression patterns of investigated anthocyanin biosynthesis genes, cotyledons of 11S91 might inherit the majority of genetic information from the white type parent, whereas the growth seedlings and developing heading tissues of 11S91 featured expression patterns of these genes more similar to 95T2-5. This comprehensive set of results provides new evidence for a better understanding of the anthocyanin biosynthesis mechanism and future breeding of new purple Brassica vegetables.

Anthocyanins, Vibrant Color Pigments, and Their Role in Skin Cancer Prevention

Until today, numerous studies evaluated the topic of anthocyanins and various types of cancer, regarding the anthocyanins' preventative and inhibitory effects, underlying molecular mechanisms, and such. However, there is no targeted review available regarding the anticarcinogenic effects of dietary anthocyanins on skin cancers. If diagnosed at the early stages, the survival rate of skin cancer is quite high. Nevertheless, the metastatic form has a short prognosis. In fact, the incidence of melanoma skin cancer, the type with high mortality, has increased exponentially over the last 30 years, causing the majority of skin cancer deaths. Malignant melanoma is considered a highly destructive type of skin cancer due to its particular capacity to grow and spread faster than any other type of cancers. Plants, in general, have been used in disease treatment for a long time, and medicinal plants are commonly a part of anticancer drugs on the market. Accordingly, this work primarily aims to emphasize the most recent improvements on the anticarcinogenic effects of anthocyanins from different plant sources, with an in-depth emphasis on melanoma skin cancer. We also briefly summarized the anthocyanin chemistry, their rich dietary sources in flowers, fruits, and vegetables, as well as their associated potential health benefits. Additionally, the importance of anthocyanins in topical applications such as their use in cosmetics is also given.

Transcriptome Analysis and Metabolic Profiling of Green and Red Mizuna (Brassica rapa L. var. japonica)

Mizuna (Brassica rapa L. var. japonica), a member of the family Brassicaceae, is rich in various health-beneficial phytochemicals, such as glucosinolates, phenolics, and anthocyanins. However, few studies have been conducted on genes associated with metabolic traits in mizuna. Thus, this study provides a better insight into the metabolic differences between green and red mizuna via the integration of transcriptome and metabolome analyses. A mizuna RNAseq analysis dataset showed 257 differentially expressed unigenes (DEGs) with a false discovery rate (FDR) of <0.05. These DEGs included the biosynthesis genes of secondary metabolites, such as anthocyanins, glucosinolates, and phenolics. Particularly, the expression of aliphatic glucosinolate biosynthetic genes was higher in the green cultivar. In contrast, the expression of most genes related to indolic glucosinolates, phenylpropanoids, and flavonoids was higher in the red cultivar. Furthermore, the metabolic analysis showed that 14 glucosinolates, 12 anthocyanins, five phenolics, and two organic acids were detected in both cultivars. The anthocyanin levels were higher in red than in green mizuna, while the glucosinolate levels were higher in green than in red mizuna. Consistent with the results of phytochemical analyses, the transcriptome data revealed that the expression levels of the phenylpropanoid and flavonoid biosynthesis genes were significantly higher in red mizuna, while those of the glucosinolate biosynthetic genes were significantly upregulated in green mizuna. A total of 43 metabolites, such as amino acids, carbohydrates, tricarboxylic acid (TCA) cycle intermediates, organic acids, and amines, was identified and quantified in both cultivars using gas chromatography coupled with time-of-flight mass spectrometry (GC-TOFMS). Among the identified metabolites, sucrose was positively correlated with anthocyanins, as previously reported.

Contribution of Special Structural Features to High Thermal Stability of a Cold-Active Transglutaminase

A cold-active transglutaminase (TGase, EC 2.3.2.13) that catalyzes the reaction of protein glutamine + protein lysine ↔ protein with γ-glutamyl-ε-lysine cross-link + NH₃ at low temperatures was reported previously. This study verified the thermal stability of the TGase from 0-80 °C. Fluorescence and CD spectra studies confirmed tertiary structural damage at 40 °C, α-helix reduction at 60 °C, and refolding during cooling to 20 °C. The TGase sequence was obtained by transcriptomics and used to build its structure. Its catalytic triad was Cys333-His403-Asp426 and its catalytic process was inferred from the model. Molecular dynamics simulation illustrated that its cold activity resulted from its flexible active site, while high thermostability was conferred by an overall rigid structure, a large amount of stable Val and Lys, and strong electrostatic interactions at the N- and C- terminals. This study fills gaps in the correlation of conformational changes with stability and activity of TGase.

Genetic and Comparative Transcriptome Analysis Revealed DEGs Involved in the Purple Leaf Formation in Brassica juncea

Brassica juncea is an important dietary vegetable cultivated and consumed in China for its edible stalks and leaves. The purple leaf mustard, which is rich in anthocyanins, is eye-catching and delivers valuable nutrition. However, the molecular mechanism involved in anthocyanin biosynthesis has not been well studied in B. juncea. Here, histological and transcriptome analyses were used to characterize the purple leaf color and gene expression profiles. Free-hand section analysis showed that the anthocyanin was mainly accumulated in the adaxial epidermal leaf cells. The anthocyanin content in the purple leaves was significantly higher than that in the green leaves. To investigate the critical genes and pathways involved in anthocyanin biosynthesis and accumulation, the transcriptome analysis was used to identify the differentially expressed genes (DEGs) between the purple and green leaves from the backcrossed BC3 segregation population in B. juncea. A total of 2,286 different expressed genes were identified between the purple and green leaves. Among them, 1,593 DEGs were up-regulated and 693 DEGs were down-regulated. There were 213 differently expressed transcription factors among them. The MYB and bHLH transcription factors, which may regulate anthocyanin biosynthesis, were up-regulated in the purple leaves. Interestingly, most of the genes involved in plant-pathogen interaction pathway were also up-regulated in the purple leaves. The late biosynthetic genes involved in anthocyanin biosynthesis were highly up-regulated in the purple leaves of B. juncea. The up regulation of BjTT8 and BjMYC2 and anthocyanin biosynthetic genes (BjC4H, BjDFR, and BjANS) may activate the purple leaf formation in B. juncea. This study may help to understand the transcriptional regulation of anthocyanin biosynthesis in B. juncea.

Red Chinese Cabbage Transcriptome Analysis Reveals Structural Genes and Multiple Transcription Factors Regulating Reddish Purple Color

Reddish purple Chinese cabbage (RPCC) is a popular variety of Brassica rapa (AA = 20). It is rich in anthocyanins, which have many health benefits. We detected novel anthocyanins including cyanidin 3-(feruloyl) diglucoside-5-(malonoyl) glucoside and pelargonidin 3-(caffeoyl) diglucoside-5-(malonoyl) glucoside in RPCC. Analyses of transcriptome data revealed 32,395 genes including 3345 differentially expressed genes (DEGs) between 3-week-old RPCC and green Chinese cabbage (GCC). The DEGs included 218 transcription factor (TF) genes and some functionally uncharacterized genes. Sixty DEGs identified from the transcriptome data were analyzed in 3-, 6- and 9-week old seedlings by RT-qPCR, and 35 of them had higher transcript levels in RPCC than in GCC. We detected cis-regulatory motifs of MYB, bHLH, WRKY, bZIP and AP2/ERF TFs in anthocyanin biosynthetic gene promoters. A network analysis revealed that MYB75, MYB90, and MYBL2 strongly interact with anthocyanin biosynthetic genes. Our results show that the late biosynthesis genes BrDFR, BrLDOX, BrUF3GT, BrUGT75c1-1, Br5MAT, BrAT-1,BrAT-2, BrTT19-1, and BrTT19-2 and the regulatory MYB genes BrMYB90, BrMYB75, and BrMYBL2-1 are highly expressed in RPCC, indicative of their important roles in anthocyanin biosynthesis, modification, and accumulation. Finally, we propose a model anthocyanin biosynthesis pathway that includes the unique anthocyanin pigments and genes specific to RPCC.

Integration of metabolome and transcriptome reveals flavonoid accumulation in the intergeneric hybrid between Brassica rapa and Raphanus sativus

Brassica rapa and Raphanus sativus are two important edible vegetables that contain numerous nutritional ingredients. However, the agronomic traits and nutritional components of the intergeneric hybrid of B. rapa and R. sativus remain poorly understood. In this study, we used a stably inherited intergeneric hybrid of B. rapa and R. sativus as a model to study its metabolome and transcriptome profiles. Morphological and cytological analysis showed the intergeneric hybrid had the expected chromosome number and normal meiosis behavior. Moreover, the metabolome analysis showed multiple important secondary metabolites, including flavonoids and glucosinolates, were significantly upregulated in the hybrid. Furthermore, transcriptome data revealed that the expression level of the important genes involved in phenylpropanoid and flavonoid pathways was significantly upregulated in the hybrid. Ultimately, our data indicate the intergeneric hybrid will be a valuable bioengineering resource and promise to become a new-type hybrid vegetable with great medicinal value in future.

Study on cyanidin metabolism in petals of pink-flowered strawberry based on transcriptome sequencing and metabolite analysis

BACKGROUND

Pink-flowered strawberry is a promising new ornamental flower derived from intergeneric hybridization (Fragaria × Potentilla) with bright color, a prolonged flowering period and edible fruits. Its flower color ranges from light pink to red. Pigment compounds accumulated in its fruits were the same as in cultivated strawberry fruits, but different from that in its flowers. However, the transcriptional events underlying the anthocyanin biosynthetic pathway have not been fully characterized in petal coloration. To gain insights into the regulatory networks related to anthocyanin biosynthesis and identify the key genes, we performed an integrated analysis of the transcriptome and metabolome in petals of pink-flowered strawberry.

RESULTS

The main pigments of red and dark pink petals were anthocyanins, among which cyanidins were the main compound. There were no anthocyanins detected in the white-flowered hybrids. A total of 50,285 non-redundant unigenes were obtained from the transcriptome databases involved in red petals of pink-flowered strawberry cultivar Sijihong at three development stages. Amongst the unigenes found to show significant differential expression, 57 were associated with anthocyanin or other flavonoid biosynthesis, in which they were regulated by 241 differentially expressed members of transcription factor families, such as 40 MYBs, 47 bHLHs, and 41 NACs. Based on a comprehensive analysis relating pigment compounds to gene expression profiles, the mechanism of flower coloration was examined in pink-flowered strawberry. A new hypothesis was proposed to explain the lack of color phenotype of the white-flowered strawberry hybrids based on the transcriptome analysis. The expression patterns of FpDFR and FpANS genes corresponded to the accumulation patterns of cyanidin contents in pink-flowered strawberry hybrids with different shades of pink. Moreover, FpANS, FpBZ1 and FpUGT75C1 genes were the major factors that led to the absence of anthocyanins in the white petals of pink-flowered strawberry hybrids. Meanwhile, the competitive effect of FpFLS and FpDFR genes might further inhibit anthocyanin synthesis.

CONCLUSIONS

The data presented herein are important for understanding the molecular mechanisms underlying the petal pigmentation and will be powerful for integrating novel potential target genes to breed valuable pink-flowered strawberry cultivars.

Transcriptome Analysis and Metabolic Profiling of Lycoris Radiata

Lycoris radiata belongs to the Amaryllidaceae family and is a bulbous plant native to South Korea, China, and Japan. Galantamine, a representative alkaloid of Amaryllidaceae plants, including L. radiata, exhibits selective and dominant acetylcholinesterase inhibition. In spite of the economic and officinal importance of L. radiata, the molecular biological and biochemical information on L. radiata is relatively deficient. Therefore, this study provides functional information of L. radiata, describe galantamine biosynthesis in the various organs, and provide transcriptomic and metabolic datasets to support elucidation of galantamine biosynthesis pathway in future studies. The results of studies conducted in duplicate revealed the presence of a total of 325,609 and 404,019 unigenes, acquired from 9,913,869,968 and 10,162,653,038 raw reads, respectively, after trimming the raw reads using CutAdapt, assembly using Trinity package, and clustering using CD-Hit-EST. All of the assembled unigenes were aligned to the public databases, including National Center for Biotechnology Information (NCBI) non-redundant protein (NR) and nucleotide (Nt) database, SWISS-PROT (UniProt) protein sequence data bank, The Arabidopsis Information Resource (TAIR), the Swiss-Prot protein database, Gene Ontology (GO), and Clusters of Orthologous Groups (COG) database to predict potential genes and provide their functional information. Based on our transcriptome data and published literatures, eight full-length cDNA clones encoding LrPAL2, LrPAL3, LrC4H2, LrC3H, LrTYDC2, LrNNR, LrN4OMT, and LrCYP96T genes, involved in galantamine biosynthesis, were identified in L. radiata. In order to investigate galantamine biosynthesis in different plant parts of L. radiata grown in a growth chamber, gene expression levels were measured through quantitative real-time polymerase chain reaction (qRT-PCR) analysis using these identified genes and galantamine levels were quantified by high-performance liquid chromatography (HPLC) analysis. The qRT-PCR data revealed high expression levels of LrNNR, LrN4OMT, and LrCYP96T in the bulbs, and, as expected, we observed higher amounts of galantamine in the bulbs than in the root and leaves. Additionally, a total of 40 hydrophilic metabolites were detected in the different organs using gas-chromatography coupled with time-of-flight mass spectrometry. In particular, a strong positive correlation between galantamine and sucrose, which provides energy for the secondary metabolite biosynthesis, was observed.

Assessing the Fate and Bioavailability of Glucosinolates in Kale (Brassica oleracea) Using Simulated Human Digestion and Caco-2 Cell Uptake Models

Glucosinolates and their hydrolysis products were characterized in fresh and in in vitro gastric and intestinal digesta of Dinosaur kale (Brassica oleracea L var. palmifolia DC). In fresh kale, glucoraphanin, sinigrin, gluconapin, gluconasturtiin, glucoerucin, glucobrasscin, and 4-methoxylglucobrassicin were identified. After 120 min of gastric digestion, the levels of glucoraphanin, sinigrin, and gluconapin decreased, and no glucoerucin or glucobrasscin was detected. However, a concomitant increase in the glucosinolate hydrolysis products allyl nitrile, 3-butenyl isothiocyanate, phenylacetonitrile, and sulforaphane was observed. This trend continued through intestinal digestion. After 120 min, the levels of allyl nitrile, 3-butenyl isothiocyanate, phenylacetonitrile, and sulforaphane were 88.19 ± 5.85, 222.15 ± 30.26, 129.17 ± 17.57, and 13.71 ± 0.62 pmol/g fresh weight, respectively. Intestinal digesta were then applied to Caco-2 cell monolayers to assess the bioavailability. After 6 h of incubation, no glucosinolates were detected and the percentage of total cellular uptake of the glucosinolate hydrolysis products ranged from 29.35% (sulforaphane) to 46.60% (allyl nitrile).

Metabolomes and transcriptomes revealed the saponin distribution in root tissues of Panax quinquefolius and Panax notoginseng

Background

Panax quinquefolius and Panax notoginseng are widely used and well known for their pharmacological effects. As main pharmacological components, saponins have different distribution patterns in the root tissues of Panax plants.

Methods

In this study, the representative ginsenosides were detected and quantified by desorption electrospray ionization mass spectrometry and high-performance liquid chromatography analysis to demonstrate saponin distribution in the root tissues of P. quinquefolius and P. notoginseng, and saponin metabolite profiles were analyzed by metabolomes to obtain the biomarkers of different root tissues. Finally, the transcriptome analysis was performed to demonstrate the molecular mechanisms of saponin distribution by gene profiles.

Results

There was saponin distribution in the root tissues differed between P. quinquefolius and P. notoginseng. Eight-eight and 24 potential biomarkers were detected by metabolome analysis, and a total of 340 and 122 transcripts involved in saponin synthesis that were positively correlated with the saponin contents (R > 0.6, P < 0.05) in the root tissues of P. quinquefolius and P. notoginseng, respectively. Among them, GDPS1, CYP51, CYP64, and UGT11 were significantly correlated with the contents of Rg1, Re, Rc, Rb2, and Rd in P. quinquefolius. UGT255 was markedly related to the content of R1; CYP74, CYP89, CYP100, CYP103, CYP109, and UGT190 were markedly correlated with the Rd content in P. notoginseng.

Conclusions

These results provided the visual and quantitative profiles of and confirmed the pivotal transcripts of CYPs and UGTs regulating the saponin distribution in the root tissues of P. quinquefolius and P. notoginseng.

Sorting out the Value of Cruciferous Sprouts as Sources of Bioactive Compounds for Nutrition and Health

Edible sprouts with germinating seeds of a few days of age are naturally rich in nutrients and other bioactive compounds. Among them, the cruciferous (Brassicaceae) sprouts stand out due to their high contents of glucosinolates (GLSs) and phenolic compounds. In order to obtain sprouts enriched in these phytochemicals, elicitation is being increasing used as a sustainable practice. Besides, the evidence regarding the bioavailability and the biological activity of these compounds after their dietary intake has also attracted growing interest in recent years, supporting the intake of the natural food instead of enriched ingredients or extracts. Also, there is a growing interest regarding their uses, consumption, and applications for health and wellbeing, in different industrial sectors. In this context, the present review aims to compile and update the available knowledge on the fundamental aspects of production, enrichment in composition, and the benefits upon consumption of diverse edible cruciferous sprouts, which are sources of phenolic compounds and glucosinolates, as well as the evidence on their biological actions in diverse pathophysiological situations and the molecular pathways involved.

Mechanism of Brassica oleracea performance in bovine infectious mastitis by bioinformatic analysis

Bovine mastitis affects dairy cattle worldwide and, despite the existing therapeutic measures, is not totally under control, leading to the need to develop alternative strategies. Brassica oleracea is a phytochemical commonly used in the control and prevention of human and animal diseases. The use of this plant in the treatment of infectious bovine mastitis has been little referenced in the literature and its molecular mechanism of action in this disease has not been clarified yet. This study aimed to reveal, through bioinformatic analysis, the molecular mechanism of action of Brassica oleracea in bovine mastitis. We investigated genes expressed in the signaling pathways of bovine mastitis and Brassica oleracea performance and elaborated the Venn diagram. A gene network was developed using the STRING 10 database. Leader genes were identified by calculating the weighted number of links (WNL). The NetworkAnalyzer plugin for Cytoscape software was used to characterize network topology. For the visualization of highly interconnected regions in the network, the MCODE was used. The BINGO and GFD-Net plugins were used to perform the ontological analysis. The TP53 and MTOR leader genes were identified in the sub-networks of the bovine mastitis signaling pathway and Brassica oleracea performance, respectively. Topological analysis confirmed the leader condition of the genes. Although the overlap of genes in the Venn diagram was not observed, the leader genes were found to be interconnected (confidence = 0.9). In the network that interconnected the leader genes two molecular complexes were detected and the ontological analysis revealed biological processes, cellular components and important molecular functions. It was concluded that Brassica oleracea may be a promising candidate to be included in a mammalian herbal cocktail against infectious bovine mastitis by interfering in the mechanisms of action of genes such as MTOR and TP53.

Transcriptome sequencing assisted discovery and computational analysis of novel SNPs associated with flowering in Raphanus sativus in-bred lines for marker-assisted backcross breeding

The sequencing of radish genome aids in the better understanding and tailoring of traits associated with economic importance. In order to accelerate the genomics assisted breeding and genetic selection, transcriptomes of 33 radish inbred lines with diverse traits were sequenced for the development of single nucleotide polymorphic (SNP) markers. The sequence reads ranged from 2,560,543,741 bp to 20,039,688,139 bp with the GC (%) of 47.80-49.34 and phred quality score (Q30) of 96.47-97.54%. A total of 4951 polymorphic SNPs were identified among the accessions after stringent filtering and 298 SNPs with efficient marker assisted backcross breeding (MAB) markers were generated from the polymorphic SNPs. Further, functional annotations of SNPs revealed the effects and importance of the SNPs identified in the flowering process. The SNPs were predominantly associated with the four major flowering related transcription factors such as MYB, MADS box (AG), AP2/EREB, and bHLH. In addition, SNPs in the vital flowering integrator gene (FT) and floral repressors (EMBRYONIC FLOWER 1, 2, and FRIGIDA) were identified among the radish inbred lines. Further, 50 SNPs were randomly selected from 298 SNPs and validated using Kompetitive Allele Specific PCR genotyping system (KASP) in 102 radish inbred lines. The homozygosity of the inbred lines varied from 56 to 96% and the phylogenetic analysis resulted in the clustering of inbred lines into three subgroups. Taken together, the SNP markers identified in the present study can be utilized for the discrimination, seed purity test, and adjusting parental combinations for breeding in radish.

The Influence of Vacuum Impregnation on Nutritional Properties of Fluidized Bed Dried Kale (Brassica oleracea L. Var. Acephala) Leaves

The aim of the work was to assess the possibility of obtaining high bioactivity dried kale using a vacuum impregnation as the preliminary processing before the drying. Kale leaves underwent vacuum impregnation in freshly squeezed onion juice and in sodium chloride solution utilising the following impregnation process parameters: At the vacuum stage, 6 kPa reduced pressure for 1 min, dosing the impregnating solution and keeping the sample under vacuum for 2 min, and then 6 min in impregnating solution at atmospheric pressure. Fluidized bed drying of kale was conducted using inert polypropylene balls, utilising a drying air temperature in a range from 70 to 130 °C. The drying kinetics were described, and the dehydrated product’s quality was assessed, on the basis of these selected characteristics: The content of chlorophylls, polyphenols and carotenoids, and antioxidant activity measured with ABTS⁺, dry matter, water activity and colour. It was determined that protective influence of vacuum impregnation before fluidized bed drying was seen only in the case of using temperatures of 90 and 110 °C. The highest content of bioactive components in dried kale was obtained in the case of using onion juice impregnation and drying at 110 °C.

Kale (Brassica oleracea var. acephala) as a superfood: Review of the scientific evidence behind the statement

Kale (Brassica oleracea var. acephala) is a cruciferous vegetable, characterized by leaves along the stem, which, in recent years, have gained a great popularity as a ´superfood´. Consequently, in a popular culture it is listed in many ´lists of the healthiest vegetables´. Without the doubt, a scientific evidences support the fact that cruciferous vegetables included in human diet can positively affect health and well-being, but remains unclear why kale is declared superior in comparison with other cruciferous. It is questionable if this statement about kale is triggered by scientific evidence or by some other factors. Our review aims to bring an overview of kale's botanical characteristics, agronomic requirements, contemporary and traditional use, macronutrient and phytochemical content and biological activity, in order to point out the reasons for tremendous kale popularity.

Expression of Carotenoid Biosynthetic Genes and Carotenoid Biosynthesis during Seedling Development of Momordica charantia

Carotenoids belong to a large group of secondary metabolites, and have pivotal roles in plants, including photosynthesis and phytohormone synthesis, pigmentation, and membrane stabilization. Additionally, carotenoids are potent antioxidants, and their health benefits are becoming increasingly prominent. In recent years, carotenoids have been studied in many plants. Furthermore, gene expression, as well as carotenoid accumulation in different parts of the bitter melon, has been investigated; however, it has not been studied in bitter melon seedlings. In this study, carotenoid accumulation and transcript levels of McGGPPS1, McGGPPS2, McPSY, McPDS, McZDS, McLCYB, McLCYE1, McLCYE2, McCXHB, and McZEP, involved in carotenoid biosynthesis, were analyzed during seedling development using HPLC and qRT-PCR. The major carotenoids that accumulated in the bitter melon seedlings were lutein and E-β-carotene. The expression of most carotenoid biosynthetic genes increased during seedling development, consistent with the accumulation of violaxanthin, lutein, zeaxanthin, β-cryptoxanthin, 13Z-β-carotene, E-β-carotene, and 9Z-β-carotene in bitter melon seedlings. The results of this study provide a firm basis for comprehending the link between gene expression and carotenoid concentration in bitter melon seedlings.