Variation of glucosinolates and quinone reductase activity among different varieties of Chinese kale and improvement of glucoraphanin by metabolic engineering

Glucosinolates in Human Health: Metabolic Pathways, Bioavailability, and Potential in Chronic Disease Prevention

Glucosinolates (GSLs) are sulfur-containing compounds predominantly found in cruciferous vegetables such as broccoli, kale, and Brussels sprouts, and are recognized for their health-promoting properties. Upon consumption, GSLs undergo hydrolysis by the enzyme myrosinase, resulting in bioactive compounds like isothiocyanates and specific indole glucosinolate degradation products, such as indole-3-carbinol (I3C) and 3,3'-diindolylmethane (DIM), which contribute to a range of health benefits, including anti-cancer, anti-inflammatory, and cardioprotective effects. This review explores the structure, metabolism, and bioavailability of GSLs. Recent evidence supports the protective role of GSLs in chronic diseases, with mechanisms including the modulation of oxidative stress, inflammation, and detoxification pathways. Furthermore, the innovative strategies to enhance GSL bioactivity, such as biofortification, genetic introgression, and optimized food processing methods, have been examined. These approaches seek to increase GSL content in edible plants, thereby maximizing their health benefits. This comprehensive review provides insights into dietary recommendations, the impact of food preparation, and recent advances in GSL bioavailability enhancement, highlighting the significant potential of these bioactive compounds in promoting human health and preventing chronic diseases.

Glucoraphanin Accumulation via Glucoraphanin Synthesis Promotion during Broccoli Germination

Glucoraphanin is an important glucosinolate which is widely distributed in Brassica vegetables and poses an anticancer effect to humans. Although researchers have paid a lot of attention to the changes in glucoraphanin concentration in seedlings of broccoli over 1-2 weeks, there has been little research focusing on the total whole-sprout glucoraphanin content within broccoli seedlings over 1-5 weeks. However, it is necessary to clarify the changes in total glucoraphanin content during the broccoli sprouting stage as broccoli seedlings are novel plant foods. This research explored glucoraphanin absolute accumulation and the biosynthesis mechanism in broccoli seedlings during a 5-week growth period. The results showed that glucoraphanin accumulation content was higher at week 4 than in the seeds. Moreover, the relative DL-methionine contents increased significantly after 3 weeks. Glucoraphanin synthetic gene expression levels were increased after 3 weeks, but the gene expressions of AOP3 (encoding 2-oxoglutarate-dependent dioxygenases) and MYR (encoding myrosinase) were significantly decreased. Furthermore, the 20 essential DEGs obtained can provide new insight into understanding the developmental regulation of broccoli seedlings. In addition, the results can also provide information on how to obtain higher glucoraphanin contents in broccoli sprouts.

CRISPR/Cas9-mediated BoaAOP2s editing alters aliphatic glucosinolate side-chain metabolic flux and increases the glucoraphanin content in Chinese kale

Glucoraphanin (GRA) is an aliphatic glucosinolate (GSL), and its hydrolysis product has powerful anticancer activity. ALKENYL HYDROXALKYL PRODUCING 2 (AOP2) gene, encodes a 2-oxoglutarate-dependent dioxygenase, which can catalyze GRA to form gluconapin (GNA). However, GRA only present in trace amounts in Chinese kale. To increase the content of GRA in Chinese kale, three copies of BoaAOP2 were isolated and edited using CRISPR/Cas9 system. The content of GRA was 11.71- to 41.29-fold (0.082-0.289 μmol g^-1 FW) higher in T1 generation of boaaop2 mutants than in wild-type plants, and this was accompanied by an increase in the GRA/GNA ratio and reductions in the content of GNA and total aliphatic GSLs. BoaAOP2.1 is an effective gene for the alkenylation of aliphatic GSLs in Chinese kale. Overall, targeted editing of CRISPR/Cas9-mediated BoaAOP2s altered aliphatic GSL side-chain metabolic flux and enhanced the GRA content in Chinese kale, suggesting that metabolic engineering of BoaAOP2s has huge potential in improving nutritional quality of Chinese kale.

Developing multifunctional crops by engineering Brassicaceae glucosinolate pathways

Glucosinolates (GSLs), found mainly in species of the Brassicaceae family, are one of the most well-studied classes of secondary metabolites. Produced by the action of myrosinase on GSLs, GSL-derived hydrolysis products (GHPs) primarily defend against biotic stress in planta. They also significantly affect the quality of crop products, with a subset of GHPs contributing unique food flavors and multiple therapeutic benefits or causing disagreeable food odors and health risks. Here, we explore the potential of these bioactive functions, which could be exploited for future sustainable agriculture. We first summarize our accumulated understanding of GSL diversity and distribution across representative Brassicaceae species. We then systematically discuss and evaluate the potential of exploited and unutilized genes involved in GSL biosynthesis, transport, and hydrolysis as candidate GSL engineering targets. Benefiting from available information on GSL and GHP functions, we explore options for multifunctional Brassicaceae crop ideotypes to meet future demand for food diversification and sustainable crop production. An integrated roadmap is subsequently proposed to guide ideotype development, in which maximization of beneficial effects and minimization of detrimental effects of GHPs could be combined and associated with various end uses. Based on several use-case examples, we discuss advantages and limitations of available biotechnological approaches that may contribute to effective deployment and could provide novel insights for optimization of future GSL engineering.

BocODD1 and BocODD2 Regulate the Biosynthesis of Progoitrin Glucosinolate in Chinese Kale

Progoitrin (2-hydroxy-3-butenyl glucosinolate, PRO) is the main source of bitterness of Brassica plants. Research on the biosynthesis of PRO glucosinolate can aid the understanding of the nutritional value in Brassica plants. In this study, four ODD genes likely involved in PRO biosynthesis were cloned from Chinese kale. These four genes, designated as BocODD1-4, shared 75-82% similarities with the ODD sequence of Arabidopsis. The sequences of these four BocODDs were analyzed, and BocODD1 and BocODD2 were chosen for further study. The gene BocODD1,2 showed the highest expression levels in the roots, followed by the leaves, flowers, and stems, which is in accordance with the trend of the PRO content in the same tissues. Both the expression levels of BocODD1,2 and the content of PRO were significantly induced by high- and low-temperature treatments. The function of BocODDs involved in PRO biosynthesis was identified. Compared with the wild type, the content of PRO was increased twofold in the over-expressing BocODD1 or BocODD2 plants. Meanwhile, the content of PRO was decreased in the BocODD1 or BocODD2 RNAi lines more than twofold compared to the wildtype plants. These results suggested that BocODD1 and BocODD2 may play important roles in the biosynthesis of PRO glucosinolate in Chinese kale.

Variation in the Main Health-Promoting Compounds and Antioxidant Activity of Different Edible Parts of Purple Flowering Stalks (Brassica campestris var. purpuraria) and Green Flowering Stalks (Brassica campestris var. campestris)

Purple flowering stalks and green flowering stalks of Brassica campestris are widely cultivated in the middle and upper reaches of the Yangtze River. Here, concentrations of the main health-promoting compounds and antioxidant capacity levels were characterized in different parts (leaves, peel, flesh, and inflorescences) of purple and green flowering stalks. There were significant differences in the concentrations of health-promoting compounds between the two variants; the concentrations of pigments, especially anthocyanidins, and gluconapin, were significantly higher in purple flowering stalks than in green flowering stalks, and the progoitrin content was significantly higher in green flowering stalks than in purple flowering stalks. The leaves were judged to be the most nutritional edible part because they had the highest concentrations of pigments, ascorbic acid, proanthocyanidins, flavonoids, and total phenolics. Antioxidant capacity was also highest in the leaves, and it was positively correlated with the concentration of health-promoting compounds. Purple flowering stalks and green flowering stalks were found to be rich in health-promoting compounds, especially glucosinolates. Overall, our findings indicate that consumption of the leaves and peel would provide the most health benefits. Some suggestions are provided regarding the processing and utilization of these edible components.

The flavor of Chinese kale sprouts is affected by genotypic variation of glucosinolates and their breakdown products

Metabolic profiling of glucosinolates and their breakdown products in sprouts of 22 Chinese kale (Brassica oleracea var. alboglabra, BOA) varieties were investigated by using high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Relationships between glucosinolate metabolites and flavor of Chinese kale sprouts were also analyzed. Results showed that compositions and contents of both glucosinolates and their breakdown products varied greatly among different varieties of Chinese kale sprouts. Gluconapin and 4,5-Epithio-pentanenitrile were the dominant glucosinolate and glucosinolate breakdown product in Chinese kale sprouts, respectively. Gluconapin and glucobrassicin were significantly related to bitterness (r = 0.577, 0.648, respectively; p < 0.05). BOA 1 and BOA 13, BOA 3 and BOA 10 are good candidates for future breeding programs since the former two varieties have light bitterness and pungency, and the latter two varieties contain high levels of glucosinolate breakdown products such as isothiocyanates and epithionitriles in sprouts.

Improvement of glucosinolates by metabolic engineering in Brassica crops

Glucosinolates (GSLs) are a class of sulfur- and nitrogen-containing, and amino acid-derived important secondary metabolites, which mainly present in plants of Brassicaceae family, including Brassica crops, such as broccoli, cabbage, and oilseed rape. The bioactive GSL metabolites confer benefits to plant defense, human health, and the unique flavor of some Brassica crops. However, certain GSL profiles have adverse effects and are known as anti-nutritional factors. This has attracted mounting attempts to increase beneficial GSLs and reduce detrimental ones in the most commonly consumed Brassica crops. We provide a comprehensive overview of metabolic engineering applied in Brassica crops to achieve this purpose, including modulation of GSL biosynthesis, ablation of GSL hydrolysis, inhibition of GSL transport processes, and redirection of metabolic flux to GSL. Moreover, advances in omics approaches, i.e., genomics, transcriptome, and metabolome, applied in the elucidation of GSL metabolism in Brassica crops, as well as promising and potential genome-editing technologies are also discussed.

Human, Animal and Plant Health Benefits of Glucosinolates and Strategies for Enhanced Bioactivity: A Systematic Review

Glucosinolates (GSs) are common anionic plant secondary metabolites in the order Brassicales. Together with glucosinolate hydrolysis products (GSHPs), they have recently gained much attention due to their biological activities and mechanisms of action. We review herein the health benefits of GSs/GSHPs, approaches to improve the plant contents, their bioavailability and bioactivity. In this review, only literature published between 2010 and March 2020 was retrieved from various scientific databases. Findings indicate that these compounds (natural, pure, synthetic, and derivatives) play an important role in human/animal health (disease therapy and prevention), plant health (defense chemicals, biofumigants/biocides), and food industries (preservatives). Overall, much interest is focused on in vitro studies as anti-cancer and antimicrobial agents. GS/GSHP levels improvement in plants utilizes mostly biotic/abiotic stresses and short periods of phytohormone application. Their availability and bioactivity are directly proportional to their contents at the source, which is affected by methods of food preparation, processing, and extraction. This review concludes that, to a greater extent, there is a need to explore and improve GS-rich sources, which should be emphasized to obtain natural bioactive compounds/active ingredients that can be included among synthetic and commercial products for use in maintaining and promoting health. Furthermore, the development of advanced research on compounds pharmacokinetics, their molecular mode of action, genetics based on biosynthesis, their uses in promoting the health of living organisms is highlighted.

Functional differences of BaPDS1 and BaPDS2 genes in Chinese kale

This study presents a systematic analysis of the functional differences between two genes that encode phytoene desaturase (PDS) in Chinese kale. The promoter sequences of both BaPDS1 and BaPDS2 were amplified and cloned, and their lengths were 2005 bp and 2000 bp, respectively. The mining of cis-acting elements in the promoters showed that the two BaPDS genes are mainly associated with light and phytohormone responsiveness. Light quality, light intensity and plant hormone treatments were conducted in seedlings of Chinese kale, and the results indicated that the response of the two genes to different factors differed. Among them, BaPDSs collectively respond to the treatment with salicylic acid and abscisic acid. With regard to response differences, BaPDS1 is sensitive to red and blue light, blue light, and strong light, while BaPDS2 responds to blue light, weak light, darkness, gibberellin and methyl jasmonate. In addition, both BaPDS1 and BaPDS2 are likely targeted to the chloroplast. Furthermore, single and double mutants of BaPDSs were generated via CRISPR/Cas9 technology. Phenotypic analysis showed that the double mutant with edited PDS1 and PDS2 was a pure albino, while the single mutants with edited PDS1 or PDS2 were partly whitened. In summary, BaPDS1 and BaPDS2 genes played different and indispensable roles in Chinese kale, and their functions were partially complementary.

CRISPR/Cas9-mediated mutagenesis of homologous genes in Chinese kale

The clustered regulatory interspaced short palindromic repeat-associated protein 9 (CRISPR/Cas9) system has developed into a powerful gene-editing tool that has been successfully applied to various plant species. However, studies on the application of the CRISPR/Cas9 system to cultivated Brassica vegetables are limited. Here, we reported CRISPR/Cas9-mediated genome editing in Chinese kale (Brassica oleracea var. alboglabra) for the first time. A stretch of homologous genes, namely BaPDS1 and BaPDS2, was selected as the target site. Several stable transgenic lines with different types of mutations were generated via Agrobacterium-mediated transformation, including BaPDS1 and BaPDS2 double mutations and BaPDS1 or BaPDS2 single mutations. The overall mutation rate reached 76.47%, and these mutations involved nucleotide changes of fewer than 10 bp. The clear albino phenotype was observed in all of the mutants, including one that harbored a mutation within an intron region, thereby indicating the importance of the intron. Cleavage in Chinese kale using CRISPR/Cas9 was biased towards AT-rich sequences. Furthermore, no off-target events were observed. Functional differences between BaPDS1 and BaPDS2 were also assessed in terms of the phenotypes of the respective mutants. In combination, these findings showed that CRISPR/Cas9-mediated targeted mutagenesis can simultaneously and efficiently modify homologous gene copies of Chinese kale and provide a convenient approach for studying gene function and improving the yield and quality of cultivated Brassica vegetables.

Evaluation of the Nutritional Quality of Chinese Kale (Brassica alboglabra Bailey) Using UHPLC-Quadrupole-Orbitrap MS/MS-Based Metabolomics

Chinese kale (Brassica alboglabra Bailey) is a widely consumed vegetable which is rich in antioxidants and anticarcinogenic compounds. Herein, we used an untargeted ultra-high-performance liquid chromatography (UHPLC)-Quadrupole-Orbitrap MS/MS-based metabolomics strategy to study the nutrient profiles of Chinese kale. Seven Chinese kale cultivars and three different edible parts were evaluated, and amino acids, sugars, organic acids, glucosinolates and phenolic compounds were analysed simultaneously. We found that two cultivars, a purple-stem cultivar W1 and a yellow-flower cultivar Y1, had more health-promoting compounds than others. The multivariate statistical analysis results showed that gluconapin was the most important contributor for discriminating both cultivars and edible parts. The purple-stem cultivar W1 had higher levels of some phenolic acids and flavonoids than the green stem cultivars. Compared to stems and leaves, the inflorescences contained more amino acids, glucosinolates and most of the phenolic acids. Meanwhile, the stems had the least amounts of phenolic compounds among the organs tested. Metabolomics is a powerful approach for the comprehensive understanding of vegetable nutritional quality. The results provide the basis for future metabolomics-guided breeding and nutritional quality improvement.

Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey)

Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28, the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology (BoaMYB28) was identified in Chinese kale (Brassica oleracea var. alboglabra Bailey). Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes in RNAi lines were considerably lower than those in the wild-type. The results suggest that BoaMYB28 has the potential to alter the aliphatic glucosinolates contents in Chinese kale at the genetic level.

De novo Transcriptome Assembly of Chinese Kale and Global Expression Analysis of Genes Involved in Glucosinolate Metabolism in Multiple Tissues

Chinese kale, a vegetable of the cruciferous family, is a popular crop in southern China and Southeast Asia due to its high glucosinolate content and nutritional qualities. However, there is little research on the molecular genetics and genes involved in glucosinolate metabolism and its regulation in Chinese kale. In this study, we sequenced and characterized the transcriptomes and expression profiles of genes expressed in 11 tissues of Chinese kale. A total of 216 million 150-bp clean reads were generated using RNA-sequencing technology. From the sequences, 98,180 unigenes were assembled for the whole plant, and 49,582~98,423 unigenes were assembled for each tissue. Blast analysis indicated that a total of 80,688 (82.18%) unigenes exhibited similarity to known proteins. The functional annotation and classification tools used in this study suggested that genes principally expressed in Chinese kale, were mostly involved in fundamental processes, such as cellular and molecular functions, the signal transduction, and biosynthesis of secondary metabolites. The expression levels of all unigenes were analyzed in various tissues of Chinese kale. A large number of candidate genes involved in glucosinolate metabolism and its regulation were identified, and the expression patterns of these genes were analyzed. We found that most of the genes involved in glucosinolate biosynthesis were highly expressed in the root, petiole, and in senescent leaves. The expression patterns of ten glucosinolate biosynthetic genes from RNA-seq were validated by quantitative RT-PCR in different tissues. These results provided an initial and global overview of Chinese kale gene functions and expression activities in different tissues.

Effects of industrial pre-freezing processing and freezing handling on glucosinolates and antioxidant attributes in broccoli florets

The effects of industrial pre-freezing processing and freezing handling on the contents of glucosinolates and antioxidants (vitamin C, polyphenols, carotenoid and chlorophyll), as well as the antioxidant capacity in broccoli (Brassica oleracea L. var. italica) florets were investigated in the present study. Our results showed that the glucosinolate accumulations were significantly decreased after pre-freezing processing, whereas elevated levels of phenols, carotenoids, chlorophyll, and also antioxidant capacity were observed in frozen broccoli florets. The contents of vitamin C remained constant during above mentioned processing. In conclusion, the current industrial freezing processing method is a good practice for the preservation of main antioxidant nutrients in broccoli florets, although some improvements in pre-freezing processing, such as steam blanching and ice-water cooling, are needed to attenuate the decrease in glucosinolate content.

Comparative Transcriptome Analyses Reveal a Special Glucosinolate Metabolism Mechanism in Brassica alboglabra Sprouts

Brassica sprouts contain abundant phytochemicals, especially glucosinolates (GSs). Various methods have been used to enhance GS content in sprouts. However, the molecular basis of GS metabolism in sprouts remains an open question. Here we employed RNA-seq analysis to compare the transcriptomes of high-GS (JL-08) and low-GS (JL-09) Brassica alboglabra sprouts. Paired-end Illumina RNA-seq reads were generated and mapped to the Brassica oleracea reference genome. The differentially expressed genes were analyzed between JL-08 and JL-09. Among these, 1477 genes were up-regulated and 1239 down-regulated in JL-09 compared with JL-08. Enrichment analysis of these differentially expressed genes showed that the GS biosynthesis had the smallest enrichment factor and the highest Q-value of all metabolic pathways in Kyoto Encyclopedia of Genes and Genomes database, indicating the main metabolic difference between JL-08 and JL-09 is the GS biosynthetic pathway. Thirty-seven genes of the sequenced data were annotated as putatively involved in GS biosynthesis, degradation, and regulation, of which 11 were differentially expressed in JL-08 and JL-09. The expression level of GS degradation enzyme myrosinase in high-GS JL-08 was lower compared with low-GS JL-09. Surprisingly, in high-GS JL-08, the expression levels of GS biosynthesis genes were also lower than those in low-GS JL-09. As the GS contents in sprouts are determined by dynamic equilibrium of seed stored GS mobilization, de novo synthesis, degradation, and extra transport, the result of this study leads us to suggest that efforts to increase GS content should focus on either raising GS content in seeds or decreasing myrosinase activity, rather than improving the expression level of GS biosynthesis genes in sprouts.

Biofortification of oilseed Brassica juncea with the anti-cancer compound glucoraphanin by suppressing GSL-ALK gene family

Glucosinolates are amino acids derived secondary metabolites, invariably present in Brassicales, which have huge health and agricultural benefits. Sulphoraphane, the breakdown product of glucosinolate glucoraphanin is known to posses anti-cancer properties. AOP (2-oxoglutarate-dependent dioxygenases) or GSL-ALK enzyme catalyzes the conversion of desirable glucoraphanin to deleterious gluconapin and progoitrin, which are present in very high amounts in most of the cultivable Brassica species including Brassica juncea. In this study we showed that B. juncea encodes four functional homologs of GSL-ALK gene and constitutive silencing of GSL-ALK homologs resulted in accumulation of glucoraphanin up to 43.11 μmoles g(-1) DW in the seeds with a concomitant reduction in the anti-nutritional glucosinolates. Glucoraphanin content was found remarkably high in leaves as well as sprouts of the transgenic lines. Transcript quantification of high glucoraphanin lines confirmed significant down-regulation of GSL-ALK homologs. Growth and other seed quality parameters of the transgenic lines did not show drastic difference, compared to the untransformed control. High glucoraphanin lines also showed higher resistance towards stem rot pathogen Sclerotinia sclerotiorum. Our results suggest that metabolic engineering of GSL-ALK has huge potential for enriching glucoraphanin content, and improve the oil quality and vegetable value of Brassica crops.

Molecular Cloning, Expression Pattern and Genotypic Effects on Glucoraphanin Biosynthetic Related Genes in Chinese Kale (Brassica oleracea var. alboglabra Bailey)

Glucoraphanin is a plant secondary metabolite that is involved in plant defense and imparts health-promoting properties to cruciferous vegetables. In this study, three genes involved in glucoraphanin metabolism, branched-chain aminotransferase 4 (BCAT4), methylthioalkylmalate synthase 1 (MAM1) and dihomomethionine N-hydroxylase (CYP79F1), were cloned from Chinese kale (Brassica oleracea var. alboglabra Bailey). Sequence homology and phylogenetic analysis identified these genes and confirmed the evolutionary status of Chinese kale. The transcript levels of BCAT4, MAM1 and CYP79F1 were higher in cotyledon, leaf and stem compared with flower and silique. BCAT4, MAM1 and CYP79F1 were expressed throughout leaf development with lower transcript levels during the younger stages. Glucoraphanin content varied extensively among different varieties, which ranged from 0.25 to 2.73 µmol·g(-1) DW (dry weight). Expression levels of BCAT4 and MAM1 were high at vegetative-reproductive transition phase, while CYP79F1 was expressed high at reproductive phase. BCAT4, MAM1 and CYP79F1 were expressed significantly high in genotypes with high glucoraphanin content. All the results provided a better understanding of the roles of BCAT4, MAM1 and CYP79F1 in the glucoraphanin biosynthesis of Chinese kale.

Effects of light quality on main health-promoting compounds and antioxidant capacity of Chinese kale sprouts

The effects of different light qualities, including white, red and blue lights, on main health-promoting compounds and antioxidant capacity of Chinese kale sprouts were investigated using light-emitting diodes (LEDs) as a light source. Our results showed that blue light treatment significantly decreased the content of gluconapin, the primary compound for bitter flavor in shoots, while increased the glucoraphanin content in roots. Moreover, the maximum content of vitamin C was detected in the white-light grown sprouts and the highest levels of total phenolic and anthocyanins, as well as the strongest antioxidant capacity were observed in blue-light grown sprouts. Taken together, the application of a colorful light source is a good practice for improvement of the consumers' acceptance and the nutritional phtyochemicals of Chinese kale sprouts.