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1.
Curr Opin Plant Biol ; 55: 47-51, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32224339

RESUMO

Plants are true organic chemists-the chemical diversity of plant metabolomes goes hand in hand with functional diversity. New, often unexpected roles are being reported for both evolutionarily conserved and well-characterised central metabolites such as amino acids, nucleotides, and sugars, and for specialized/secondary metabolites such as carotenoids, glucosinolates, and terpenoids. Our review aims to highlight recent studies reporting novel roles of metabolites and to emphasize the importance of cell-wide identification of metabolite-protein complexes for the comprehensive, functional understanding of the plant metabolome.


Assuntos
Metaboloma , Plantas , Aminoácidos , Carotenoides , Glucosinolatos
2.
Phytochemistry ; 175: 112371, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32283438

RESUMO

During the last years halogenated compounds have drawn a lot of attention. Metabolites with one or more halogen atoms are often more active than their non-halogenated derivatives like indole-3-acetic acid (IAA) and 4-Cl-IAA. Within this work, bacterial flavin-dependent tryptophan halogenase genes were inserted into Brassica rapa ssp. pekinensis (Chinese cabbage) with the aim to produce novel halogenated indole compounds. It was investigated which tryptophan-derived indole metabolites, such as indole glucosinolates or potential degradation products can be synthesized by the transgenic root cultures. In vivo and in vitro activity of halogenases heterologously produced was shown and the production of chlorinated tryptophan in transgenic root lines was confirmed. Furthermore, chlorinated indole-3-acetonitrile (Cl-IAN) was detected. Other tryptophan-derived indole metabolites, such as IAA or indole glucosinolates were not found in the transgenic roots in a chlorinated form. The influence of altered growth conditions on the amount of produced chlorinated compounds was evaluated. We found an increase in Cl-IAN production at low temperatures (8 °C), but otherwise no significant changes were observed. Furthermore, we were able to regenerate the wild type and transgenic root cultures to adult plants, of which the latter still produced chlorinated metabolites. Therefore, we conclude that the genetic information had been stably integrated. The transgenic plants showed a slightly altered phenotype compared to plants grown from seeds since they also still expressed the rol genes. By this approach we were able to generate various stably transformed plant materials from which it was possible to isolate chlorinated tryptophan and Cl-IAN.


Assuntos
Brassica rapa , Brassica , Glucosinolatos , Indóis , Raízes de Plantas , Plantas Geneticamente Modificadas
3.
Food Chem ; 321: 126694, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32244140

RESUMO

Red cabbage contains glucosinolates, precursors to health-promoting isothiocyanates. However, raw cabbage often releases mainly epithionitriles and nitriles from glucosinolates. To increase isothiocyanate formation, the effect of acid usage in the preparation of red cabbage was evaluated. Moreover, the effects of the chosen boiling method (acidic boiled red cabbage versus neutral boiled blue cabbage) on glucosinolate degradation were investigated using UHPLC-DAD-ToF-MS and GC-MS. The addition of vinegar significantly increased isothiocyanate formation of cabbage salad from 0.09 to 0.21 µmol/g fresh weight, while lemon juice only slightly increased isothiocyanate formation. Acidic boiled red cabbage degraded glucosinolates and increased nitrile formation, while in neutral boiled blue cabbage, glucosinolates were stable. However, shortly boiled blue cabbage (5 min) had the highest isothiocyanate levels (0.08 µmol/g fresh weight). Thus, for a diet rich in isothiocyanates it is recommended to acidify raw cabbage salads and prepare shortly boiled blue cabbage instead of red cabbage.


Assuntos
Brassica/metabolismo , Culinária/métodos , Glucosinolatos/metabolismo , Saladas , Ácido Acético/química , Brassica/química , Cromatografia Líquida de Alta Pressão , Comportamento Alimentar , Análise de Alimentos/métodos , Sucos de Frutas e Vegetais , Cromatografia Gasosa-Espectrometria de Massas , Hábitos , Concentração de Íons de Hidrogênio , Isotiocianatos/química , Isotiocianatos/metabolismo , Nitrilos/metabolismo
5.
Food Chem ; 319: 126498, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32169761

RESUMO

Effect of melatonin treatment on visual quality and contents of health-promoting compounds of broccoli florets under room temperature was investigated in the present study. Broccoli florets were treated with 1 µM melatonin and then stored at room temperature. Results showed that melatonin treatment could delay the post-harvest senescence of broccoli, and performed well in maintaining higher levels of antioxidants, such as carotenoids, vitamin C and total phenols, as well as higher antioxidant capacity than the control. Besides, 1 µM melatonin treatment sustained higher content of glucosinolates, and also resulted in increased percentage of the most potent anticarcinogenic profile, glucoraphanin. Further analysis revealed that 1 µM melatonin strongly induced the expression of glucosinolate biosynthesis-related genes BoMYB28, BoMYB34, BoCYP79F1, and BoCYP79B2, as well as BoTGG1, a gene involved in glucosinolate hydrolysis. In conclusion, post-harvest treatment with 1 µM melatonin is potential in maintaining visual quality and health-promoting properties of broccoli florets.


Assuntos
Brassica/efeitos dos fármacos , Melatonina/farmacologia , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Brassica/metabolismo , Carotenoides/metabolismo , Glucosinolatos/metabolismo , Imidoésteres/metabolismo , Fenóis/metabolismo , Temperatura
6.
Plant Physiol Biochem ; 150: 39-48, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32112998

RESUMO

Triunsaturated fatty acids are substrates for the synthesis of the defense hormone jasmonate which plays roles in resistance to numerous fungal pathogens. However, relatively little is known about other potential roles of di-unsaturated and triunsaturated fatty acids in resistance to fungal pathogens - in particular those that can attack plants at the seedling stage. We examined the roles of polyunsaturated fatty acids (PUFAs) in Arabidopsis thaliana during attack by the necrotrophic pathogen, Botrytis cinerea. We found that PUFA-deficient Arabidopsis mutants (fad2-1, fad2-3 and fad3-2 fad7-2 fad8 [fad trip]) displayed an unexpectedly strong resistance to B. cinerea at the cotyledon stage. Preliminary analyses revealed no changes in the expression of defense genes, however cuticle permeability defects were detected in both fad2-1 and fad trip mutants. Analysis of B. cinerea development on the surface of cotyledons revealed arrested hyphal growth on fad2-3 and fad trip mutants and 28% reduction in fungal adhesion on fad2-3 cotyledons. Surface metabolite analysis from the cotyledons of PUFA mutants led to the identification of 7-methylsulfonylheptyl glucosinolate (7MSOHG), which over-accumulated on the plant surface. We linked the appearance of 7MSOHG to defects in cuticle composition and permeability of mutants and show that its appearance correlates with resistance to B. cinerea.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Botrytis , Glucosinolatos , Antifúngicos/farmacologia , Arabidopsis/química , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Botrytis/efeitos dos fármacos , Resistência à Doença/genética , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Regulação da Expressão Gênica de Plantas , Glucosinolatos/genética , Glucosinolatos/farmacologia
7.
Plant Physiol Biochem ; 150: 151-161, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32142988

RESUMO

Brassica is one of the most economically important genus of the Brassicaceae family, encompassing several key crops like Brassica napus (cabbage) and broccoli (Brassica oleraceae var. italica). This family is well known for their high content of characteristic secondary metabolites such as glucosinolates (GLS) compounds, recognize for their beneficial health properties and role in plants defense. In this work, we have looked through gene clusters involved in the biosynthesis of GLS, by combining genomic analysis with biochemical pathways and chemical diversity assessment. A total of 101 Brassicaceae genes involved in GLS biosynthesis were identified, using a multi-database approach. Through a UPGMA and PCA analysis on the 101 GLS genes recorded, revealed a separation between the genes mainly involved in GLS core structure synthesis and genes belonging to the CYP450s and MYBs gene families. After, a detailed phylogenetic analysis was conducted to better understand the disjunction of the aliphatic and indolic genes, by focusing on CYP79F1-F2 and CYP81F1-F4, respectively. Our results point to a recent diversification of the aliphatic CYP79F1 and F2 genes in Brassica crops, while for indolic genes an earliest diversification is observed for CYP81F1-F4 genes. Chemical diversity revealed that Brassica crops have distinct GLS chemo-profiles from other Brassicaceae genera; being highlighted the high contents of GLS found among the Diplotaxis species. Also, we have explored GLS-rich species as a new source of taxa with great agronomic potential, particularly in abiotic stress tolerance, namely Diplotaxis, the closest wild relatives of Brassica crops.


Assuntos
Brassica , Brassicaceae , Glucosinolatos , Brassicaceae/química , Brassicaceae/classificação , Brassicaceae/genética , Variação Genética , Genômica , Glucosinolatos/química , Filogenia , Estresse Fisiológico/genética
8.
Food Chem ; 315: 126275, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32004982

RESUMO

The effects of individual epi-brassinolide (eBL) and NaCl, as well as their combination on contents of main phytochemicals and antioxidant capacity of Chinese kale sprouts were investigated. Our results showed that the application of 100 nM eBL decreased the contents of individual and total glucosinolates, while treatments of 160 mM NaCl both alone and combined with 100 nM eBL enhanced the glucosinolates accumulation by promoting the expression of genes involved in glucosinolate biosynthesis in Chinese kale sprouts and the combined treatment led to significantly higher content of most glucosinolate profiles. Moreover, it also elevated the contents of ascorbic acid and total carotenoids, whereas did not influence the total phenolics and antioxidant capacity. These findings indicated that the combined treatment of 100 nM eBL plus 160 mM NaCl could provide a new strategy to improve the main health promoting compounds in Chinese kale sprouts.


Assuntos
Brassica/química , Brassinosteroides/química , Compostos Fitoquímicos/química , Plântula/química , Cloreto de Sódio/química , Esteroides Heterocíclicos/química , Antioxidantes/química , Ácido Ascórbico/química , Carotenoides/química , Glucosinolatos/química , Fenóis/química , Cloreto de Sódio/farmacologia
9.
J Agric Food Chem ; 68(10): 3121-3131, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32053364

RESUMO

A new method to simultaneously analyze various glucosinolates (GSLs) and isothiocyanates (ITCs) by reversed-phase ultra-high-performance liquid chromatography-electron spray ionization-tandem mass spectrometry has been developed and validated for 14 GSLs and 15 ITCs. It involved derivatization of ITCs with N-acetyl-l-cysteine (NAC). The limits of detection were 0.4-1.6 µM for GSLs and 0.9-2.6 µM for NAC-ITCs. The analysis of Sinapis alba, Brassica napus, and Brassica juncea extracts spiked with 14 GSLs and 15 ITCs indicated that the method generally had good intraday (≤10% RSD) and interday precisions (≤16% RSD). Recovery of the method was unaffected by the extracts and within 71-110% for GSLs and 66-122% for NAC-ITCs. The method was able to monitor the enzymatic hydrolysis of standard GSLs to ITCs in mixtures. Furthermore, GSLs and ITCs were simultaneously determined in Brassicaceae plant extracts before and after myrosinase treatment. This method can be applied to further investigate the enzymatic conversion of GSLs to ITCs in complex mixtures.


Assuntos
Brassicaceae/química , Cromatografia Líquida de Alta Pressão/métodos , Glucosinolatos/química , Isotiocianatos/química , Extratos Vegetais/química , Sinapis/química , Espectrometria de Massas em Tandem/métodos , Cromatografia de Fase Reversa/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos
10.
Photochem Photobiol Sci ; 19(2): 217-228, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31961357

RESUMO

Pyridoxine (vitamin B6) and its vitamers are used by living organisms both as enzymatic cofactors and as antioxidants. We used Arabidopsis pyridoxine biosynthesis mutant pdx1.3-1 to study the involvement of the PLP-synthase main polypeptide PDX1 in plant responses to ultraviolet radiation of two different qualities, one containing primarily UV-A (315-400 nm) and the other containing both UV-A and UV-B (280-315 nm). The antioxidant capacity and the flavonoid and glucosinolate (GS) profiles were examined. As an indicator of stress, Fv/Fm of photosystem II reaction centers was used. In pdx1.3-1, UV-A + B exposure led to a significant 5% decrease in Fv/Fm on the last day (day 15), indicating mild stress at this time point. The antioxidant capacity of Col-0 wildtype increased significantly (50-73%) after 1 and 3 days of UV-A + B. Instead, in pdx1.3-1, the antioxidant capacity significantly decreased by 44-52% over the same time period, proving the importance of a full complement of functional PDX1 genes for the detoxification of reactive oxygen species. There were no significant changes in the flavonoid glycoside profile under any light condition. However, the GS profile was significantly altered, both with respect to Arabidopsis accession and exposure to UV. The difference in flavonoid and GS profiles reflects that the GS biosynthesis pathway contains at least one pyridoxine-dependent enzyme, whereas no such enzyme is used in flavonoid biosynthesis. Also, there was strong correlation between the antioxidant capacity and the content of some GS compounds. Our results show that vitamin B6 vitamers, functioning both as antioxidants and co-factors, are of importance for the physiological fitness of plants.


Assuntos
Antioxidantes/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos da radiação , Carbono-Nitrogênio Liases/metabolismo , Glucosinolatos/biossíntese , Raios Ultravioleta , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Carbono-Nitrogênio Liases/genética , Cromatografia Líquida de Alta Pressão , Flavonoides/biossíntese , Glucosinolatos/análise , Mutagênese , Complexo de Proteína do Fotossistema II/metabolismo , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo
11.
Food Chem ; 312: 126028, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31896454

RESUMO

The present study investigated the distribution of several primary metabolites (soluble sugar, protein, and mineral) and secondary metabolites (carotenoids, vitamin C, anthocyanin, flavonoids, and total phenolic compounds) among the leaf layers of headed cabbage. The leaf layers of two cultivars were separated and numbered sequentially from the outer to the inner leaves. The fructose and glucose content of the inner leaf layers was significantly greater than that of the outer layers. Similarly, the level of glucosinolates increased gradually from the outer leaves to the umbilicus of the leaf head. However, the content of antioxidants decreased from the outer leaves to the core of the leaf head, in line with the antioxidant capacity. The levels of soluble protein and mineral shared the similar decreasing trend. These results provide a reference for consumers to choose optimal fractions of whole cabbage heads in order to cater to their particular dietary needs.


Assuntos
Brassica/metabolismo , Antocianinas/metabolismo , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Carotenoides/metabolismo , Flavonoides/metabolismo , Glucosinolatos/metabolismo , Fenóis/metabolismo , Folhas de Planta/metabolismo
12.
J Chem Ecol ; 46(2): 186-197, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31953704

RESUMO

The horseradish flea beetle Phyllotreta armoraciae exclusively feeds on Brassicaceae, which contain glucosinolates as characteristic defense compounds. Although glucosinolates are usually degraded by plant enzymes (myrosinases) to toxic isothiocyanates after ingestion, P. armoraciae beetles sequester glucosinolates. Between and within brassicaceous plants, the glucosinolate content and composition can differ drastically. But how do these factors influence sequestration in P. armoraciae? To address this question, we performed a five-day feeding experiment with three Arabidopsis thaliana lines that differ four-fold in glucosinolate content and the composition of aliphatic and indolic glucosinolates. We quantified the amounts of ingested, sequestered, and excreted glucosinolates, and analyzed the changes in glucosinolate levels and composition in beetles before and after feeding on Arabidopsis. P. armoraciae accumulated almost all ingested glucosinolate types. However, some glucosinolates were accumulated more efficiently than others, and selected glucosinolates were modified by the beetles. The uptake of new glucosinolates correlated with a decrease in the level of stored glucosinolates so that the total glucosinolate content remained stable at around 35 nmol/mg beetle fresh weight. Beetles excreted previously stored as well as ingested glucosinolates from Arabidopsis, which suggests that P. armoraciae regulate their endogenous glucosinolate level by excretion. The metabolic fate of ingested glucosinolates, i.e. the proportions of sequestered and excreted glucosinolates, depended on glucosinolate type, content, and composition in the food plant. Overall, P. armoraciae sequestered and excreted up to 41% and 31% of the total ingested aliphatic and indolic glucosinolates from Arabidopsis, respectively. In summary, we show that glucosinolate variability in Brassicaceae influences the composition but not the level of sequestered glucosinolates in P. armoraciae beetles.


Assuntos
Brassicaceae/química , Besouros/metabolismo , Glucosinolatos/metabolismo , Animais , Arabidopsis/química , Arabidopsis/metabolismo , Brassicaceae/metabolismo , Fezes/química , Glucosinolatos/química , Hemolinfa/química , Hemolinfa/metabolismo , Interações Hospedeiro-Parasita
13.
J Sci Food Agric ; 100(3): 1064-1071, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31713870

RESUMO

BACKGROUND: Glucosinolates (GSLs) are secondary metabolites, mainly existing in Brassica vegetables. Their breakdown products have health benefits and contribute to the distinctive taste of these vegetables. Because of their high value, there is a lot of interest in developing breeding strategies to increase the content of beneficial GSLs in Brassica species. GSLs are synthesized from certain amino acids and their biological roles depend largely on the structure of their side chains. Flavin-containing monooxygenase (FMOGS-OX ) genes are involved in the synthesis of these side chains. To better understand GSL biosynthesis, we sequenced the transcriptomes of turnip (Brassica rapa var. rapa) tubers at four developmental stages (S1-S4) and determined their GSL content. RESULTS: The total GSL content was high at the early stage (S1) of tuber development and increased up to S3, then decreased at S4. We detected 61 differentially expressed genes, including five FMOGS-OX genes, that were related for GSL biosynthesis among the four developmental stages. Most of these genes were highly expressed at stages S1 to S3, but their expression was much lower at S4. We estimated the effect of the five FMOGS-OX genes on GSL content by overexpressing them in turnip hairy roots and found that the amount of aliphatic GSLs increased significantly in the transgenic plants. CONCLUSION: The transcriptome data and characterization of genes involved in GSL biosynthesis, particularly the FMOGS-OX genes, will be valuable for improving the yield of beneficial GSLs in turnip and other Brassica crops. © 2019 Society of Chemical Industry.


Assuntos
Brassica rapa/enzimologia , Brassica rapa/crescimento & desenvolvimento , Glucosinolatos/biossíntese , Oxigenases de Função Mista/metabolismo , Proteínas de Plantas/metabolismo , Vias Biossintéticas , Brassica rapa/genética , Brassica rapa/metabolismo , Dinitrocresóis/metabolismo , Regulação da Expressão Gênica de Plantas , Oxigenases de Função Mista/genética , Proteínas de Plantas/genética , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Transcriptoma
14.
J Plant Physiol ; 244: 153088, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31812906

RESUMO

Zinc (Zn) is one of the important elements of plant growth, however, at elevated level it is toxic. Exposure of Chinese cabbage to elevated Zn2+ concentrations (5 and 10 µM ZnCl2) resulted in enhancement of total sulfur and organic sulfur concentration. Transcript level of APS reductase (APR) as a key enzyme in biosynthesis of primary sulfur compounds (cysteine and thiols), was up-regulated in both shoot and root upon exposure to elevated Zn2+, which was accompanied by an increase in the concentration of cysteine in both tissues. In contrast, the concentration of thiols increased only in the root by 5.5 and 15-fold at 5 and 10 µM Zn2+, respectively, which was in accompanied by an upregulation of ATP sulfurylase, an enzyme responsible for activation of sulfate. An elevated content of glucosinolates, mostly indolic glucosinolates, only in the shoot of plants exposed to excess level of Zn2+ coincided with an increase in gene expression of key biosynthetic enzymes and regulators (CYP79B3, CYP83B1, MYB34). Thus distinct acuumulation patterns of sulfur containing compounds in root and shoot of Chinese cabbage may be a strategy for Chinese cabbage to combat with exposure to excess Zn.


Assuntos
Brassica/metabolismo , Glucosinolatos/metabolismo , Proteínas de Plantas/metabolismo , Compostos de Sulfidrila/metabolismo , Zinco/administração & dosagem , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Regulação para Cima
15.
J Sci Food Agric ; 100(4): 1616-1624, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31773731

RESUMO

BACKGROUND: Brassica oleracea var. alboglabra (Chinese kale) is an important vegetable grown in southern China. This study was aimed at searching for environmentally friendly and affordable approaches to increase the production of medicinally relevant glucosinolates and phenolic compounds in Chinese kale plants. For this purpose, the foliar application of liquiritin at 0 (control), 250, 500 and 750 ppm was tested starting from the four-leaf stage and repeated every two weeks until plants were two months old. RESULTS: Foliar application of liquiritin in Chinese kale plants significantly increased glucosinolates and total phenolic content, in a dose-dependent manner. Compared with control plants, 2.3- and 1.9-fold increases in yields of glucosinolates and total phenolic content, respectively, were corroborated in Chinese kale plants treated with 750 ppm of liquiritin. Along with rises in the content of eight different glucosinolates, liquiritin elicitation effectively increased the concentration of glycosilated and acylated flavonoids and hydroxycinnamic acids. The expression of genes involved in glucosinolate and phenolic biosynthesis was significantly higher in liquiritin-treated plants as compared to controls. CONCLUSIONS: Liquiritin elicitation is a feasible and environmentally friendly practice for increasing the production of medicinally important glucosinolates and phenolic compounds in Chinese kale, which may improve this plant's value as a nutraceutical food. This study also contributes to understanding the molecular mechanisms underlying liquiritin elicitation. This is the first report documenting the use of liquiritin for an elicitation purpose in plants. © 2019 Society of Chemical Industry.


Assuntos
Brassica/metabolismo , Produção Agrícola/métodos , Flavanonas/farmacologia , Glucosídeos/farmacologia , Glucosinolatos/análise , Fenóis/análise , Brassica/química , Brassica/efeitos dos fármacos , China , Produção Agrícola/instrumentação , Flavonoides/análise , Flavonoides/metabolismo , Glucosinolatos/metabolismo , Fenóis/metabolismo , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Verduras/química , Verduras/efeitos dos fármacos , Verduras/metabolismo
16.
Plant Mol Biol ; 102(1-2): 171-184, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31792713

RESUMO

KEY MESSAGE: Thus study found the temporal and spatial relationship between production of aliphatic glucosinolate compounds and the expression profile of glucosinolate-related genes during growth and development in radish, Chinese cabbage, and their intergeneric hybrid baemoochae plants. Glucosinolates (GSLs) are one of major bioactive compounds in Brassicaceae plants. GSLs play a role in defense against microbes as well as chemo-preventative activity against cancer, which draw attentions from plant scientists. We investigated the temporal relationship between production of aliphatic Glucosinolate (GSLs) compounds and the expression profile of GSL related genes during growth and development in radish, Chinese cabbage, and their intergeneric hybrid, baemoochae. Over the complete life cycle, Glucoraphasatin (GRH) and glucoraphanin (GRE) predominated in radish, whereas gluconapin (GNP), glucobrassicanapin (GBN), and glucoraphanin (GRA) abounded in Chinese cabbage. Baemoochae contained intermediate levels of all GSLs studied, indicating inheritance from both radish and Chinese cabbage. Expression patterns of BCAT4, CYP79F1, CYP83A1, UGT74B1, GRS1, FMOgs-ox1, and AOP2 genes showed a correlation to their corresponding encoded proteins in radish, Chinese cabbage, and baemoochae. Interestingly, there is a sharp change in gene expression pattern involved in side chain modification, particularly GRS1, FMOgs-ox1, and AOP2, among these plants during the vegetative and reproductive stage. For instance, the GRS1 was strongly expressed during leaf development, while both of FMOgs-ox1 and AOP2 was manifested high in floral tissues. Furthermore, expression of GRS1 gene which is responsible for GRH production was predominantly expressed in leaf tissues of radish and baemoochae, whereas it was only slightly detected in Chinese cabbage root tissue, explaining why radish has an abundance of GRH compared to other Brassica plants. Altogether, our comprehensive and comparative data proved that aliphatic GSLs biosynthesis is dynamically and precisely regulated in a tissue- and development-dependent manner in Brassicaceae family members.


Assuntos
Brassica/genética , Brassica/metabolismo , Regulação da Expressão Gênica de Plantas , Glucosinolatos/genética , Glucosinolatos/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Genes de Plantas/genética , Imidoésteres/metabolismo , Estágios do Ciclo de Vida , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Transcriptoma
17.
Physiol Plant ; 168(1): 174-187, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30706476

RESUMO

Tryptophan is one of the amino acids that cannot be produced in humans and has to be acquired primarily from plants. In Arabidopsis thaliana (Arabidopsis), the tryptophan synthase beta subunit (TSB) genes have been found to catalyze the biosynthesis of tryptophan. Here, we report the isolation and characterization of two TSB genes from Brassica oleracea (broccoli), designated BoTSB1 and BoTSB2. Overexpressing BoTSB1 or BoTSB2 in Arabidopsis resulted in higher tryptophan content and the accumulation of indole-3-acetic acid (IAA) and indole glucosinolates in rosette leaves. Therefore, the transgenic plants showed a series of high auxin phenotypes, including long hypocotyls, large plants and a high number of lateral roots. The spatial expression of BoTSB1 and BoTSB2 was detected by quantitative real-time PCR in broccoli and by expressing the ß-glucuronidase reporter gene (GUS) controlled by the promoters of the two genes in Arabidopsis. BoTSB1 was abundantly expressed in vascular tissue of shoots and inflorescences. Compared to BoTSB1, BoTSB2 was expressed at a very low level in shoots but at a higher level in roots. We further investigated the expression response of the two genes to several hormone and stress treatments. Both genes were induced by methyl jasmonate (MeJA), salicylic acid (SA), gibberellic acid (GA), Flg22 (a conserved 22-amino acid peptide derived from bacterial flagellin), wounding, low temperature and NaCl and were repressed by IAA. Our study enhances the understanding of tryptophan biosynthesis and its regulation in broccoli and Arabidopsis. In addition, we provide evidence that TSB genes can potentially be a good tool to breed plants with high biomass and high nutrition.


Assuntos
Brassica/genética , Glucosinolatos/biossíntese , Ácidos Indolacéticos/metabolismo , Triptofano/biossíntese , Arabidopsis , Brassica/enzimologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Plantas Geneticamente Modificadas
18.
Phytochemistry ; 169: 112100, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31771793

RESUMO

The glucosinolates (GSLs) is a well-defined group of plant metabolites characterized by having an S-ß-d-glucopyrano unit anomerically connected to an O-sulfated (Z)-thiohydroximate function. After enzymatic hydrolysis, the sulfated aglucone can undergo rearrangement to an isothiocyanate, or form a nitrile or other products. The number of GSLs known from plants, satisfactorily characterized by modern spectroscopic methods (NMR and MS) by mid-2018, is 88. In addition, a group of partially characterized structures with highly variable evidence counts for approximately a further 49. This means that the total number of characterized GSLs from plants is somewhere between 88 and 137. The diversity of GSLs in plants is critically reviewed here, resulting in significant discrepancies with previous reviews. In general, the well-characterized GSLs show resemblance to C-skeletons of the amino acids Ala, Val, Leu, Trp, Ile, Phe/Tyr and Met, or to homologs of Ile, Phe/Tyr or Met. Insufficiently characterized, still hypothetic GSLs include straight-chain alkyl GSLs and chain-elongated GSLs derived from Leu. Additional reports (since 2011) of insufficiently characterized GSLs are reviewed. Usually the crucial missing information is correctly interpreted NMR, which is the most effective tool for GSL identification. Hence, modern use of NMR for GSL identification is also reviewed and exemplified. Apart from isolation, GSLs may be obtained by organic synthesis, allowing isotopically labeled GSLs and any kind of side chain. Enzymatic turnover of GSLs in plants depends on a considerable number of enzymes and other protein factors and furthermore depends on GSL structure. Identification of GSLs must be presented transparently and live up to standard requirements in natural product chemistry. Unfortunately, many recent reports fail in these respects, including reports based on chromatography hyphenated to MS. In particular, the possibility of isomers and isobaric structures is frequently ignored. Recent reports are re-evaluated and interpreted as evidence of the existence of "isoGSLs", i.e. non-GSL isomers of GSLs in plants. For GSL analysis, also with MS-detection, we stress the importance of using authentic standards.


Assuntos
Glucosinolatos , Plantas/metabolismo , Glucosinolatos/síntese química , Glucosinolatos/química , Glucosinolatos/metabolismo , Estrutura Molecular , Plantas/química
19.
Food Chem ; 308: 125657, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31669950

RESUMO

This study investigated the effects of drought stress on Chinese cabbage (Chcab) by measuring plant growth responses, total antioxidant enzyme activities, the contents of bioactive compounds including glucosinolates (GLS, aliphatic and indolic), and binding with human serum albumin (HSA). Forty-day-old Chinese cabbage (Brassica rapa L. ssp. pekinensis) seedlings were transplanted into pots and maintained for three weeks at 10% (drought-treated, D-T) and 30% (control, C) soil water. The total leaf number, leaf area, and fresh and dry weights were significantly lower in D-T Chcab than in controls. Total GLSs and catalase activities were found to be significantly higher in D-T Chcab than in controls. Indolic GLSs were significantly higher than aliphatic GLSs in D-T Chcab. These results show that D-T Chcab reduced growth parameters and binding properties with HSA and influenced total contents of GLSs, polyphenols, flavonoids, total antioxidant enzyme activities, catalase and peroxidase.


Assuntos
Antioxidantes/metabolismo , Brassica rapa/metabolismo , Secas , Glucosinolatos/análise , Flavonoides/metabolismo , Glucosinolatos/metabolismo , Polifenóis/metabolismo , Plântula/metabolismo , Estresse Fisiológico
20.
Food Chem ; 308: 125573, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31639598

RESUMO

In this study an active antimicrobial packaging based on the controlled release of Allyl isothiocyanate (AITC) from mustard seed was designed. The effect of fat content and particle size of ground mustard seeds on formation and release of AITC was investigated and the underlying mechanisms were highlighted. A smaller size of mustard particles resulted in more sinigrin conversion to AITC and a higher release of AITC in the headspace. The fat content has an important role on AITC release, a decreased fat content decreased AITC levels in the particles and increased the amount of AITC in the headspace. Based on the results of the sinigrin hydrolysis, the AITC surface exchange rate and the AITC fat solubility, an overall picture of the factors influencing the AITC release from the particles is proposed, which describes formation of AITC and its partitioning between the compartments of the particles and the headspace.


Assuntos
Gorduras/química , Isotiocianatos/química , Mostardeira/química , Antibacterianos , Glucosinolatos/química , Tamanho da Partícula , Embalagem de Produtos , Sementes/química
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