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We previously found that feeding rats with broccoli or cauliflower leads to the formation of characteristic DNA adducts in the liver, intestine and various other tissues. We identified the critical substances in the plants as 1-methoxy-3-indolylmethyl (1-MIM) glucosinolate and its degradation product 1-MIM-OH. DNA adduct formation and the mutagenicity of 1-MIM-OH in cell models were drastically enhanced when human sulfotransferase (SULT) 1A1 was expressed. The aim of this study was to clarify the role of SULT1A1 in DNA adduct formation by 1-MIM-OH in mouse tissues in vivo. Furthermore, we compared the endogenous mouse Sult1a1 and transgenic human SULT1A1 in the activation of 1-MIM-OH using genetically modified mouse strains. We orally treated male wild-type (wt) and Sult1a1-knockout (ko) mice, as well as corresponding lines carrying the human SULT1A1-SULT1A2 gene cluster (tg and ko-tg), with 1-MIM-OH. N2-(1-MIM)-dG and N6-(1-MIM)-dA adducts in DNA were analysed using isotope-dilution UPLC-MS/MS. In the liver, caecum and colon adducts were abundant in mice expressing mouse and/or human SULT1A1, but were drastically reduced in ko mice (1.2–10.6% of wt). In the kidney and small intestine, adduct levels were high in mice carrying human SULT1A1-SULT1A2 genes, but low in wt and ko mice (1.8–6.3% of tg-ko). In bone marrow, adduct levels were very low, independently of the SULT1A1 status. In the stomach, they were high in all four lines. Thus, adduct formation was primarily controlled by SULT1A1 in five out of seven tissues studied, with a strong impact of differences in the tissue distribution of mouse and human SULT1A1. The behaviour of 1-MIM-OH in these models (levels and tissue distribution of DNA adducts; impact of SULTs) was similar to that of methyleugenol, classified as "probably carcinogenic to humans". Thus, there is a need to test 1-MIM-OH for carcinogenicity in animal models and to study its adduct formation in humans consuming brassicaceous foodstuff. [ABSTRACT FROM AUTHOR]

Inflammatory diseases are strongly associated with global morbidity and mortality. Several mediators are involved in this process, including proinflammatory interleukins and cytokines produced by damaged tissues that, somehow, act as initiators of the autoreactive immune response. Bioactive compounds present in plant-based foods and byproducts have been largely considered active agents with the potential to treat or prevent inflammatory diseases, being a valuable alternative to traditional therapeutic agents used nowadays, which present several side effects. In this regard, the present research uncovers the anti-inflammatory activity of the bioaccessible fraction of broccoli stalks processed, by applying different conditions that render specific concentrations of bioactive sulforaphane (SFN). The raw materials' extracts exhibited significantly different contents of total glucosinolates (GSLs) that ranged between 3993.29 and 12,296.48 mg/kg dry weight (dw), with glucoraphanin as the most abundant one, followed by GI and GE. The indolic GSLs were represented by hydroxy-glucobrassicin, glucobrassicin, methoxy-glucobrassicin, and neo-glucobrassicin, with the two latter as the most abundant. Additionally, SFN and indole-3-carbinol were found in lower concentrations than the corresponding GSL precursors in the raw materials. When exploring the bioaccessibility of these organosulfur compounds, the GSL of all matrices remained at levels lower than the limit of detection, while SFN was the only breakdown product that remained stable and at quantifiable concentrations. The highest concentration of bioaccessible SFN was provided by the high-ITC materials (~4.00 mg/kg dw). The results retrieved on the cytotoxicity of the referred extracts evidenced that the range of supplementation of growth media tested (0.002–430.400 µg of organosulfur compounds/mL) did not display cytotoxic effects on Caco-2 cells. The obtained extracts were assessed based on their capacity to reduce the production of key proinflammatory cytokines (interleukin 6 (IL-6), IL-8, and TNF-α) by the intestinal epithelium. Most of the tested processing conditions provided plant material with significant anti-inflammatory activity and the absence of cytotoxic effects. These data confirm that SFN from broccoli stalks, processed to optimize the bioaccessible concentration of SFN, may be potential therapeutic leads to treat or prevent human intestinal inflammation. [ABSTRACT FROM AUTHOR]

The organic sulfur-containing compounds glucosinolates (GSLs) and the novel gasotransmitter H2S are known to have cardioprotective effects. This study investigated the antioxidant effects and H2S-releasing potential of three GSLs ((3E)-4-(methylsulfanyl)but-3-enyl GSL or glucoraphasatin, 4-hydroxybenzyl GSL or glucosinalbin, and (RS)-6-(methylsulfinyl)hexyl GSL or glucohesperin) in rat cardiac cells. It was found that all three GSLs had no effect on cardiac cell viability but were able to protect against H2O2-induced oxidative stress and cell death. NaHS, a H2S donor, also protected the cells from H2O2-stimulated oxidative stress and cell death. The GSLs alone or mixed with cysteine, N-acetylcysteine, glutathione, H2O2, iron and pyridoxal-5′-phosphate, or mouse liver lysates did not induce H2S release. The addition of GSLs also did not alter endogenous H2S levels in cardiac cells. H2O2 significantly induced cysteine oxidation in the cystathionine gamma-lyase (CSE) protein and inhibited the H2S production rate. In conclusion, this study found that the three tested GSLs protect cardiomyocytes from oxidative stress and cell death but independently of H2S signaling. [ABSTRACT FROM AUTHOR]

We previously found that feeding rats with broccoli or cauliflower leads to the formation of characteristic DNA adducts in the liver, intestine and various other tissues. We identified the critical substances in the plants as 1-methoxy-3-indolylmethyl (1-MIM) glucosinolate and its degradation product 1-MIM-OH. DNA adduct formation and the mutagenicity of 1-MIM-OH in cell models were drastically enhanced when human sulfotransferase (SULT) 1A1 was expressed. The aim of this study was to clarify the role of SULT1A1 in DNA adduct formation by 1-MIM-OH in mouse tissues in vivo. Furthermore, we compared the endogenous mouse Sult1a1 and transgenic human SULT1A1 in the activation of 1-MIM-OH using genetically modified mouse strains. We orally treated male wild-type (wt) and Sult1a1-knockout (ko) mice, as well as corresponding lines carrying the human SULT1A1-SULT1A2 gene cluster (tg and ko-tg), with 1-MIM-OH. N2-(1-MIM)-dG and N6-(1-MIM)-dA adducts in DNA were analysed using isotope-dilution UPLC-MS/MS. In the liver, caecum and colon adducts were abundant in mice expressing mouse and/or human SULT1A1, but were drastically reduced in ko mice (1.2–10.6% of wt). In the kidney and small intestine, adduct levels were high in mice carrying human SULT1A1-SULT1A2 genes, but low in wt and ko mice (1.8–6.3% of tg-ko). In bone marrow, adduct levels were very low, independently of the SULT1A1 status. In the stomach, they were high in all four lines. Thus, adduct formation was primarily controlled by SULT1A1 in five out of seven tissues studied, with a strong impact of differences in the tissue distribution of mouse and human SULT1A1. The behaviour of 1-MIM-OH in these models (levels and tissue distribution of DNA adducts; impact of SULTs) was similar to that of methyleugenol, classified as “probably carcinogenic to humans”. Thus, there is a need to test 1-MIM-OH for carcinogenicity in animal models and to study its adduct formation in humans consuming brassicaceous foodstuff.

Sulfur is an essential element for plant growth, development and resistance to environmental stresses. Glucosinolates (GSLs), a group of sulfur rich secondary metabolites found in Brassicaceae plants, are known for their defensive properties against pathogens and herbivores. Due to their integration of a large proportion of total sulfur, their biosynthesis and degradation are closely linked to sulfur metabolism. It has been demonstrated that GSLs can be broken down to release sulfur and facilitate the production of other thio-metabolites when the plant is under stress. However, the regulation of this process is still not fully understood. In this study, we constructed two broccoli LSU (low sulfur responsive) gene overexpressing lines, 35S::BoLSU1 and 35S::BoLSU2, to detect changes in GSL metabolism after sulfur deficiency treatment. The results showed that BoLSU1 and BoLSU2 inhibit the biosynthesis of aliphatic GSLs, while also promoting their degradation and increasing the content of glutathione (GSH), leading to the reallocation of sulfur from the GSL pool to other thio-metabolites such as GSH. Furthermore, this regulation of GSL metabolism mediated by BoLSU1 and BoLSU2 is found to be dependent on myrosinases BGLU28 and BGLU30. Our study provides insight into the physiological role of LSU proteins and their regulation of sulfur metabolism. [ABSTRACT FROM AUTHOR]

The organic sulfur-containing compounds glucosinolates (GSLs) and the novel gasotransmitter H2S are known to have cardioprotective effects. This study investigated the antioxidant effects and H2S-releasing potential of three GSLs ((3E)-4-(methylsulfanyl)but-3-enyl GSL or glucoraphasatin, 4-hydroxybenzyl GSL or glucosinalbin, and (RS)-6-(methylsulfinyl)hexyl GSL or glucohesperin) in rat cardiac cells. It was found that all three GSLs had no effect on cardiac cell viability but were able to protect against H2O2-induced oxidative stress and cell death. NaHS, a H2S donor, also protected the cells from H2O2-stimulated oxidative stress and cell death. The GSLs alone or mixed with cysteine, N-acetylcysteine, glutathione, H2O2, iron and pyridoxal-5′-phosphate, or mouse liver lysates did not induce H2S release. The addition of GSLs also did not alter endogenous H2S levels in cardiac cells. H2O2 significantly induced cysteine oxidation in the cystathionine gamma-lyase (CSE) protein and inhibited the H2S production rate. In conclusion, this study found that the three tested GSLs protect cardiomyocytes from oxidative stress and cell death but independently of H2S signaling.

Inflammatory diseases are strongly associated with global morbidity and mortality. Several mediators are involved in this process, including proinflammatory interleukins and cytokines produced by damaged tissues that, somehow, act as initiators of the autoreactive immune response. Bioactive compounds present in plant-based foods and byproducts have been largely considered active agents with the potential to treat or prevent inflammatory diseases, being a valuable alternative to traditional therapeutic agents used nowadays, which present several side effects. In this regard, the present research uncovers the anti-inflammatory activity of the bioaccessible fraction of broccoli stalks processed, by applying different conditions that render specific concentrations of bioactive sulforaphane (SFN). The raw materials’ extracts exhibited significantly different contents of total glucosinolates (GSLs) that ranged between 3993.29 and 12,296.48 mg/kg dry weight (dw), with glucoraphanin as the most abundant one, followed by GI and GE. The indolic GSLs were represented by hydroxy-glucobrassicin, glucobrassicin, methoxy-glucobrassicin, and neo-glucobrassicin, with the two latter as the most abundant. Additionally, SFN and indole-3-carbinol were found in lower concentrations than the corresponding GSL precursors in the raw materials. When exploring the bioaccessibility of these organosulfur compounds, the GSL of all matrices remained at levels lower than the limit of detection, while SFN was the only breakdown product that remained stable and at quantifiable concentrations. The highest concentration of bioaccessible SFN was provided by the high-ITC materials (~4.00 mg/kg dw). The results retrieved on the cytotoxicity of the referred extracts evidenced that the range of supplementation of growth media tested (0.002–430.400 µg of organosulfur compounds/mL) did not display cytotoxic effects on Caco-2 cells. The obtained extracts were assessed based on their capacity to reduce the production of key proinflammatory cytokines (interleukin 6 (IL-6), IL-8, and TNF-α) by the intestinal epithelium. Most of the tested processing conditions provided plant material with significant anti-inflammatory activity and the absence of cytotoxic effects. These data confirm that SFN from broccoli stalks, processed to optimize the bioaccessible concentration of SFN, may be potential therapeutic leads to treat or prevent human intestinal inflammation.

Salvia hispanica (chia) is a highly nutritious food source and has gained popularity due to its high omega-3 fatty acid content. Red spider mites are a serious problem in the production of S. hispanica. However, no study has been conducted to analyze the defensive response to the infestation of red spider mites in S. hispanica. To elucidate the molecular mechanisms of the defensive response of S. hispanica to red spider mites, we performed a transcriptomic analysis of S. hispanica when infested by red spider mites. In the comparative assessment of leaf transcriptomes, a total of 1743 differentially expressed genes (DEGs) were identified between control and mite-infested S. hispanica. From these, 1208 (69%) transcripts were upregulated and 535 (31%) were downregulated. The DEGs included transcription factors, defense hormones, and secondary metabolites that were either suppressed or activated in response to spider mite herbivory. Gene Ontology (GO) enrichment analysis revealed that plant secondary metabolites, such as glucosinolates, and signaling pathways, including the jasmonic acid signaling pathway, may play an important role in the defense against red spider mites. This study provides novel insights into the defense response of S. hispanica to insect herbivory and could be a resource for the improvement of pest resistance in the chia. [ABSTRACT FROM AUTHOR]

Soil salinity can have various negative consequences on agricultural products, from their quality and production to their aesthetic traits. In this work, the possibility to use salt-affected vegetables, that otherwise would be discarded, as a source of nutraceuticals was explored. To this aim, rocket plants, a vegetable featuring bioactive compounds such as glucosinolates, were exposed to increasing NaCl concentrations in hydroponics and analysed for their content in bioactive compounds. Salt levels higher than 68 mM produced rocket plants that did not comply with European Union regulations and would therefore be considered a waste product. Anyway, our findings, obtained by Liquid Chromatography-High Resolution Mass Spectrometry, demonstrated a significant increase in glucosinolates levels in such salt-affected plants. opening the opportunity for a second life of these market discarded products to be recycled as glucosinolates source. Furthermore, an optimal situation was found at NaCl 34 mM in which not only were the aesthetic traits of rocket plants not affected, but also the plants revealed a significant enrichment in glucosinolates. This can be considered an advantageous situation in which the resulting vegetables still appealed to the market and showed improved nutraceutical aspects. [ABSTRACT FROM AUTHOR]

Phenolic compounds and glucosinolates are secondary plant metabolites that play fundamental roles in plant resistance to abiotic stress. These compounds have been found to increase in stress situations related to plant adaptive capacity. This review assesses the functions of phenolic compounds and glucosinolates in plant interactions involving abiotic stresses such as drought, salinity, high temperature, metals toxicity, and mineral deficiency or excess. Furthermore, their relation with water uptake and transport mediated through aquaporins is reviewed. In this way, the increases of phenolic compounds and glucosinolate synthesis have been related to primary responses to abiotic stress and induction of resistance. Thus, their metabolic pathways, root exudation, and external application are related to internal cell and tissue movement, with a lack of information in this latter aspect. [ABSTRACT FROM AUTHOR]

During Agrobacterium rhizogenes–plant interaction, the rolB gene is transferred into the plant genome and is stably inherited in the plant's offspring. Among the numerous effects of rolB on plant metabolism, including the activation of secondary metabolism, its effect on plant defense systems has not been sufficiently studied. In this work, we performed a proteomic analysis of rolB-expressing Arabidopsis thaliana plants with particular focus on defense proteins. We found a total of 77 overexpressed proteins and 64 underexpressed proteins in rolB-transformed plants using two-dimensional gel electrophoresis and MALDI mass spectrometry. In the rolB-transformed plants, we found a reduced amount of scaffold proteins RACK1A, RACK1B, and RACK1C, which are known as receptors for activated C-kinase 1. The proteomic analysis showed that rolB could suppress the plant immune system by suppressing the RNA-binding proteins GRP7, CP29B, and CP31B, which action are similar to the action of type-III bacterial effectors. At the same time, rolB plants induce the massive biosynthesis of protective proteins VSP1 and VSP2, as well as pathogenesis-related protein PR-4, which are markers of the activated jasmonate pathway. The increased contents of glutathione-S-transferases F6, F2, F10, U19, and DHAR1 and the osmotin-like defense protein OSM34 were found. The defense-associated protein PCaP1, which is required for oligogalacturonide-induced priming and immunity, was upregulated. Moreover, rolB-transformed plants showed the activation of all components of the PYK10 defense complex that is involved in the metabolism of glucosinolates. We hypothesized that various defense systems activated by rolB protect the host plant from competing phytopathogens and created an effective ecological niche for A. rhizogenes. A RolB → RACK1A signaling module was proposed that might exert most of the rolB-mediated effects on plant physiology. Our proteomics data are available via ProteomeXchange with identifier PXD037959. [ABSTRACT FROM AUTHOR]

The glucosinolate transporters 1/2/3 (GTR1/2/3) from the Nitrate and Peptide transporter Family (NPF) play an essential role in the transport, accumulation, and distribution of the specialized plant metabolite glucosinolates. Due to representing both antinutritional and health-promoting compounds, there is increasing interest in characterizing GTRs from various plant species. We generated seven artificial glucosinolates (either aliphatic or benzenic) bearing different fluorophores (Fluorescein, BODIPY, Rhodamine, Dansylamide, and NBD) and investigated the ability of GTR1/2/3 from Arabidopsis thaliana to import the fluorescent glucosinolates (F-GSLs) into oocytes from Xenopus laevis. Five out of the seven F-GSLs synthesized were imported by at least one of the GTRs. GTR1 and GTR2 were able to import three F-GSLs actively above external concentration, while GTR3 imported only one actively. Competition assays indicate that the F-GSLs are transported by the same mechanism as non-tagged natural glucosinolates. The GTR-mediated F-GSL uptake is detected via a rapid and sensitive assay only requiring simple fluorescence measurements on a standard plate reader. This is highly useful in investigations of glucosinolate transport function and provides a critical prerequisite for elucidating the relationship between structure and function through high-throughput screening of GTR mutant libraries. The F-GSL themselves may also be suitable for future studies on glucosinolate transport in vivo. [ABSTRACT FROM AUTHOR]

Glucosinolates (GLS) were extracted and purified from Lepidium meyenii (Maca) root. Purified GLS were analyzed without desulfation by UPLC–ESI–MS. Glucosinolates were decomposed into benzyl isothiocyanate (BITC) by thioglucosidase. DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power were used to evaluate antioxidant activity of Maca crude extract (MCE), total GLS, and BITC. Maca crude extract showed the highest antioxidant activity among them, and BITC showed no antioxidant activity at concentrations less than 10 mg/mL. Cytotoxicity on five human cancer cell lines and the inhibition rate of NO production were used to evaluate the activity of anti-cancer and anti-inflammatory of total GLS and BITC. The inhibition rate of NO production of 50 μg/mL BITC can reach 99.26% and the cell viability of 100 μg/mL BITC on five tumor cell lines is less than 3%. The results show that BITC may be used as a promising anti-cancer and anti-inflammatory drug. [ABSTRACT FROM AUTHOR]

Sulfur is an essential element for plant growth, development and resistance to environmental stresses. Glucosinolates (GSLs), a group of sulfur rich secondary metabolites found in Brassicaceae plants, are known for their defensive properties against pathogens and herbivores. Due to their integration of a large proportion of total sulfur, their biosynthesis and degradation are closely linked to sulfur metabolism. It has been demonstrated that GSLs can be broken down to release sulfur and facilitate the production of other thio-metabolites when the plant is under stress. However, the regulation of this process is still not fully understood. In this study, we constructed two broccoli LSU (low sulfur responsive) gene overexpressing lines, 35S::BoLSU1 and 35S::BoLSU2, to detect changes in GSL metabolism after sulfur deficiency treatment. The results showed that BoLSU1 and BoLSU2 inhibit the biosynthesis of aliphatic GSLs, while also promoting their degradation and increasing the content of glutathione (GSH), leading to the reallocation of sulfur from the GSL pool to other thio-metabolites such as GSH. Furthermore, this regulation of GSL metabolism mediated by BoLSU1 and BoLSU2 is found to be dependent on myrosinases BGLU28 and BGLU30. Our study provides insight into the physiological role of LSU proteins and their regulation of sulfur metabolism.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, accounting for about 90% of cases. Sorafenib, lenvatinib, and the combination of atezolizumab and bevacizumab are considered first-line treatments for advanced HCC. However, clinical application of these drugs has also caused some adverse reactions such as hypertension, elevated aspartate aminotransferases, and proteinuria. At present, natural products and their derivatives have drawn more and more attention due to less side effects as cancer treatments. Isothiocyanates (ITCs) are one type of hydrolysis products from glucosinolates (GLSs), secondary plant metabolites found exclusively in cruciferous vegetables. Accumulating evidence from encouraging in vitro and in vivo animal models has demonstrated that ITCs have multiple biological activities, especially their potentially health-promoting activities (antibacterial, antioxidant, and anticarcinogenic effects). In this review, we aim to comprehensively summarize the chemopreventive, anticancer, and chemosensitizative effects of ITCs on HCC, and explain the underlying molecular mechanisms. [ABSTRACT FROM AUTHOR]

The Brassica oleracea industry generates large amounts of by-products to which value could be added because of the characteristics of their composition. The aim was to extract different fibre fractions from broccoli stalks to obtain potential new added-value ingredients. Using an ethanol and water extraction procedure, two fibre-rich fractions (total fibre fraction, TFB, and insoluble fibre fraction, IFB) were obtained. These fractions were analysed to determine the nutritional, (poly)phenols and glucosinolates composition and physicochemical properties, comparing the results with those of freeze-dried broccoli stalks (DBS). Although TFB showed a higher content of total dietary fibre, IFB had the same content of insoluble dietary fibre as TFB (54%), better hydration properties, higher content of glucosinolates (100 mg/100 g d.w.) and (poly)phenols (74.7 mg/100 g d.w.). The prebiotic effect was evaluated in IFB and compared with DBS by in vitro fermentation with human faecal slurries. After 48 h, the short-chain fatty acid (SCFA) production was higher with IFB than with DBS because of the greater presence of both uronic acids, the main component of pectin, and (poly)phenols. These results reveal that novel fibre-rich ingredients—with antioxidant, technological and physiological effects—could be obtained from broccoli stalks by using green extraction methods. [ABSTRACT FROM AUTHOR]

Heat stress is one of the most common agrometeorological risks in crop production in the middle and lower reaches of the Yangtze River in China. This study aimed to investigate whether glutamic acid (Glu) or poly-γ-glutamic acid (γ-PGA) biostimulants can improve the thermotolerance of a cool-season Chinese cabbage (Brassica rapa L. ssp. pekinensis) crop. Priming with Glu (2.0 mM) or γ-PGA (20 mg·L−1) was conducted at the third leaf stage by applying as daily foliar sprays for 5 days before 5 days of heat stress (45 °C in 16-h light/35 °C in 8-h dark). Coupled with morpho-physiological and biochemical analyses, transcriptomes of Glu or γ-PGA-primed Chinese cabbage under heat stress were examined by RNA-seq analysis. The results showed that the thermotolerance conferred by Glu and γ-PGA priming was associated with the increased parameters of vegetative growth, gas exchange, and chlorophyll fluorescence. Compared with the control, the dry weights of plants treated with Glu and γ-PGA increased by 51.52% and 39.39%, respectively. Glu and γ-PGA application also significantly increased the contents of total chlorophyll by 42.21% and 23.12%, and carotenoid by 32.00% and 24.00%, respectively. In addition, Glu- and γ-PGA-primed plants markedly inhibited the levels of malondialdehyde, electrolyte leakage, and super-oxide anion radical, which was accompanied by enhanced activity levels of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD). Enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) categories within the differentially expressed genes (DEGs) functional clusters of RNA-seq data indicated that the expression levels of the genes for DNA replication, DNA repair system, linoleic acid metabolism, cysteine and methionine metabolism, glutathione metabolism, purine and pyrimidine metabolism, carotenoid biosynthesis, and plant–pathogen interaction were commonly up-regulated by both Glu and γ-PGA priming. Glu treatment enhanced the expression levels of the genes involved in aliphatic glucosinolate and 2-oxocarboxylic acid, while γ-PGA treatment activated carotenoid cleavage reaction to synthesize abscisic acid. Taken together, both Glu and γ-PGA have great potential for the preadaptation of Chinese cabbage seedlings to heat stress, with Glu being more effective than γ-PGA. [ABSTRACT FROM AUTHOR]

Rising temperatures and pronounced drought are significantly affecting biodiversity worldwide and reducing yields and quality of Brassica crops. To elucidate the mechanisms of tolerance, 33 kale accessions (B. oleracea var. acephala) were evaluated for individual (osmotic and elevated temperature stress) and combined stress (osmotic + temperature). Using root growth, biomass and proline content as reliable markers, accessions were evaluated for stress responses. Four representatives were selected for further investigation (photosynthetic performance, biochemical markers, sugar content, specialized metabolites, transcription level of transcription factors NAC, HSF, DREB and expression of heat shock proteins HSP70 and HSP90): very sensitive (392), moderately sensitive (395), tolerant (404) and most tolerant (411). Accessions more tolerant to stress conditions were characterized by higher basal content of proline, total sugars, glucosinolates and higher transcription of NAC and DREB. Under all stress conditions, 392 was characterized by a significant decrease in biomass, root growth, photosynthesis performance, fructan content, especially under osmotic and combined stress, a significant increase in HSF transcription and HSP accumulation under temperature stress and a significant decrease in NAC transcription under all stresses. The most tolerant accession under all applied stresses, 411 showed the least changes in all analyzed parameters compared with the other accessions. [ABSTRACT FROM AUTHOR]

Myrosinase can hydrolyze glucosinolates to generate isothiocyanates, which have cancer prevention and anti-cancer properties. The main sources of myrosinase are cruciferous plants. To further improve the efficiency of isothiocyanates preparation, it is necessary to explore novel sources of myrosinases. In this study, we described a bacterium, Shewanella baltica Myr-37, isolated from marine mud, capable of producing a novel myrosinase (Smyr37) with a molecular weight of 100 kDa. The crude enzyme of Smyr37 showed the highest activity at 50 °C and pH 8.0. The sinigrin- and glucoraphanin-hydrolyzing activities of Smyr37 were 6.95 and 5.87 U/mg, respectively. Moreover, when the reaction temperature was 40 °C and pH was 7.0, the crude enzyme of Smyr37 could efficiently degrade glucoraphanin into sulforaphane within 25 min with a yield of 0.57 mg/mL. The corresponding conversion efficiency of sulforaphane from glucoraphanin was 89%. In summary, S. baltica Myr-37 myrosinase Smyr37, a novel myrosinase, can be used in the preparation of isothiocyanates. [ABSTRACT FROM AUTHOR]

Despite the great advancements made in cancer treatment, there are still many unsatisfied aspects, such as the wide palette of side effects and the drug resistance. There is an obvious increasing scientific attention towards nature and what it can offer the human race. Natural products can be used to treat many diseases, of which some plant products are currently used to treat cancer. Plants produce secondary metabolites for their signaling mechanisms and natural defense. A variety of plant-derived products have shown promising anticancer properties in vitro and in vivo. Rather than recreating the natural production environment, ongoing studies are currently setting various strategies to significantly manipulate the quantity of anticancer molecules in plants. This review focuses on the recently studied secondary metabolite agents that have shown promising anticancer activity, outlining their potential mechanisms of action and pathways. [ABSTRACT FROM AUTHOR]

Soil salinity can have various negative consequences on agricultural products, from their quality and production to their aesthetic traits. In this work, the possibility to use salt-affected vegetables, that otherwise would be discarded, as a source of nutraceuticals was explored. To this aim, rocket plants, a vegetable featuring bioactive compounds such as glucosinolates, were exposed to increasing NaCl concentrations in hydroponics and analysed for their content in bioactive compounds. Salt levels higher than 68 mM produced rocket plants that did not comply with European Union regulations and would therefore be considered a waste product. Anyway, our findings, obtained by Liquid Chromatography-High Resolution Mass Spectrometry, demonstrated a significant increase in glucosinolates levels in such salt-affected plants. opening the opportunity for a second life of these market discarded products to be recycled as glucosinolates source. Furthermore, an optimal situation was found at NaCl 34 mM in which not only were the aesthetic traits of rocket plants not affected, but also the plants revealed a significant enrichment in glucosinolates. This can be considered an advantageous situation in which the resulting vegetables still appealed to the market and showed improved nutraceutical aspects.

The transcription factor WRKY33 is a vital regulator of the biological process of the necrotrophic fungus Botrytis cinerea (B. cinerea). However, its specific regulatory mechanism remains to be further investigated. In non-heading Chinese cabbage (NHCC, Brassica campestris (syn. Brassica rapa) ssp. Chinensis), our previous study showed that BcWRKY33A is induced not only by salt stress, but also by B. cinerea infection. Here, we noticed that BcWRKY33A is expressed in trichomes and confer plant defense resistance. Disease symptoms and qRT-PCR analyses revealed that BcWRKY33A-overexpressing and -silencing lines were less and more severely impaired, respectively, than wild type upon B. cinerea treatment. Meanwhile, the transcripts' abundance of indolic glucosinolates' (IGSs) biosynthetic genes is consistent with plants' B. cinerea tolerance. Identification and expression pattern analysis of BcMYB51s showed that BcMYB51-3 has a similar trend to BcWRKY33A upon B. cinerea infection. Moreover, BcWRKY33A directly binds to the BcMYB51-3 promoter, which was jointly confirmed by Y1H, dual-LUC, and EMSA assays. The importance of MYB51, the homolog of BcMYB51-3, in the BcWRKY33A-mediated B. cinerea resistance was also verified using the TRV-based VIGS system. Overall, our data concludes that BcWRKY33A directly activates the expression of BcMYB51-3 and downstream IGSs' biosynthetic genes, thereby improving the B. cinerea tolerance of NHCC plants. [ABSTRACT FROM AUTHOR]

Flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) is one of the most popular vegetables in China. However, the loss of the functional ingredients in postharvest flowering Chinese cabbage during storage is still serious, owing to the unclear causes of the metabolic shifts. Herein, benzoic acid, chlorine dioxide, and 1-methylcyclopropene (1-MCP) could maintain the quality of postharvest flowering Chinese cabbage, and 1-MCP showed the best effect. Furthermore, transcript-metabolite profiling of the treatments revealed a transcript-metabolite correlation network of the flavonoid biosynthesis pathways with a range of 3 to 3662 differentially expressed genes (DEGs) and a range of 23 to 37 differentially accumulated metabolites (DAMs). Surprisingly, 1-MCP had the best effect on shelf life among the treatments, although chlorine dioxide could stimulate the expression of four critical differential genes (Bra007142, Bra008792, Bra009358, and Bra027457) involved in delaying flavonoid degradation (hesperetin, chalcone, rutin, baicalein). As a result, our findings will help to improve our understanding of the regulation of flavonoid production in relation to the quality of postharvest flowering Chinese cabbage during storage. [ABSTRACT FROM AUTHOR]

Brassica vegetables are widely consumed all over the world, especially in North America, Asia, and Europe. They are a rich source of sulfur compounds, such as glucosinolates (GLSs) and isothiocyanates (ITCs), which provide health benefits but are also suspected of having a goitrogenic effect. Adhering to PRISMA guidelines, we conducted a systematic review to assess the impact of dietary interventions on thyroid function, in terms of the potential risk for people with thyroid dysfunctions. We analyzed the results of 123 articles of in vitro, animal, and human studies, describing the impact of brassica plants and extracts on thyroid mass and histology, blood levels of TSH, T3, T4, iodine uptake, and the effect on thyroid cancer cells. We also presented the mechanisms of the goitrogenic potential of GLSs and ITCs, the limitations of the studies included, as well as further research directions. The vast majority of the results cast doubt on previous assumptions claiming that brassica plants have antithyroid effects in humans. Instead, they indicate that including brassica vegetables in the daily diet, particularly when accompanied by adequate iodine intake, poses no adverse effects on thyroid function.

Phenolic compounds and glucosinolates are secondary plant metabolites that play fundamental roles in plant resistance to abiotic stress. These compounds have been found to increase in stress situations related to plant adaptive capacity. This review assesses the functions of phenolic compounds and glucosinolates in plant interactions involving abiotic stresses such as drought, salinity, high temperature, metals toxicity, and mineral deficiency or excess. Furthermore, their relation with water uptake and transport mediated through aquaporins is reviewed. In this way, the increases of phenolic compounds and glucosinolate synthesis have been related to primary responses to abiotic stress and induction of resistance. Thus, their metabolic pathways, root exudation, and external application are related to internal cell and tissue movement, with a lack of information in this latter aspect.

Bulygin et al. [[1]] present a study on the mechanisms of damage recognition and catalysis by Apurinic/apyrimidinic (AP) endonucleases, key DNA repair enzymes in the base excision repair (BER) pathway. In this work, the authors present an overview of currently known PET-degrading enzymes, highlighting the structural and activity characteristics of these enzymes and summarizing recently reported engineering efforts to improve their activity. Enzymes are able to catalyze a wide diversity of chemical reactions in nature, and they do it at an amazing level. [Extracted from the article]

The aim of the study was to present the fingerprint of different Lepidium peruvianum tuber extracts showing glucosinolates-containing substances possibly playing an important role in preventinting dementia and other memory disorders. Different phenotypes of Lepidium peruvianum (Brassicaceae) tubers were analysed for their glucosinolate profile using a liquid chromatograph coupled with mass spectrometer (HPLC-ESI-QTOF-MS/MS platform). Qualitative analysis in 50% ethanolic extracts confirmed the presence of ten compounds: aliphatic, indolyl, and aromatic glucosinolates, with glucotropaeolin being the leading one, detected at levels between 0–1.57% depending on phenotype, size, processing, and collection site. The PCA analysis showed important variations in glucosinolate content between the samples and different ratios of the detected compounds. Applied in vitro activity tests confirmed inhibitory properties of extracts and single glucosinolates against acetylcholinesterase (AChE) (15.3–28.9% for the extracts and 55.95–57.60% for individual compounds) and butyrylcholinesterase (BuChE) (71.3–77.2% for the extracts and 36.2–39.9% for individual compounds). The molecular basis for the activity of glucosinolates was explained through molecular docking studies showing that the tested metabolites interacted with tryptophan and histidine residues of the enzymes, most likely blocking their active catalytic side. Based on the obtained results and described mechanism of action, it could be concluded that glucosinolates exhibit inhibitory properties against two cholinesterases present in the synaptic cleft, which indicates that selected phenotypes of L. peruvianum tubers cultivated under well-defined environmental and ecological conditions may present a valuable plant material to be considered for the development of therapeutic products with memory-stimulating properties. [ABSTRACT FROM AUTHOR]

Not all agricultural practices are sustainable; however, non-thermal plasma treatment of seeds may be an eco-friendly alternative to improve macroscopic plant growth parameters. Despite the numerous successful results of plasma-seed treatments reported in the literature, there is a large gap in our understanding of how non-thermal plasma treatments affect seeds, especially due to the plethora of physical, chemical, and biological variables. This study uses RNA sequencing to characterize the changes in gene transcription in Arabidopsis thaliana (L.) Heynh. seeds 6 days after exposure to surface dielectric barrier discharge plasma treatment. Here, we provide an overview of all pathways that are differentially expressed where few genes are upregulated and many genes are downregulated. Our results reveal that plasma treatment time is a parameter that can activate different pathways in plant defense. An 80 s treatment upregulates the glucosinolate pathway, a defense response to insects and herbivores to deter feeding, whereas a shorter treatment of 60 s upregulates the phenylpropanoid pathway, which reinforces the cell wall with lignin and produces antimicrobial compounds, a defense response to bacterial or fungal plant pathogens. It seems that plasma elicits a wounding response from the seed in addition to redox changes. This suggests that plasma treatment can be potentially applied in agriculture to protect plants against abiotic and biotic stresses without discharging residues into the environment. [ABSTRACT FROM AUTHOR]

Radish (Raphanus sativus L.) is rich in specific glucosinolates (GSLs), which benefit human health and special flavor formation. Although the basic GSLs metabolic pathway in Brassicaceae plants is clear, the regulating mechanism for specific glucosinolates content in radish fleshy taproots is not well understood. In this study, we discovered that there was a significant difference in the GSLs profiles and the content of various GSLs components. Glucoraphasatin (GRH) is the most predominant GSL in radish taproots of different genotypes as assessed by HPLC analysis. Further, we compared the taproot transcriptomes of three radish genotypes with high and low GSLs content by employing RNA-seq. Totally, we identified forty-one differentially expressed genes related to GSLs metabolism. Among them, thirteen genes (RsBCAT4, RsIPMDH1, RsMAM1a, RsMAM1b, RsCYP79F1, RsGSTF9, RsGGP1, RsSUR1, RsUGT74C1, RsST5b, RsAPK1, RsGSL-OH, and RsMYB28) were significantly higher co-expressed in the high content genotypes than in low content genotype. Notably, correlation analysis indicated that the expression level of RsMYB28, as an R2R3 transcription factor directly regulating aliphatic glucosinolate biosynthesis, was positively correlated with the GRH content. Co-expression network showed that RsMYB28 probably positively regulated the expression of the above genes, particularly RsSUR1, and consequently the synthesis of GRH. Moreover, the molecular mechanism of the accumulation of this 4-carbon (4C) GSL in radish taproots was explored. This study provides new perspectives on the GSLs accumulation mechanism and genetic improvements in radish taproots. [ABSTRACT FROM AUTHOR]

The Brassica oleracea industry generates large amounts of by-products to which value could be added because of the characteristics of their composition. The aim was to extract different fibre fractions from broccoli stalks to obtain potential new added-value ingredients. Using an ethanol and water extraction procedure, two fibre-rich fractions (total fibre fraction, TFB, and insoluble fibre fraction, IFB) were obtained. These fractions were analysed to determine the nutritional, (poly)phenols and glucosinolates composition and physicochemical properties, comparing the results with those of freeze-dried broccoli stalks (DBS). Although TFB showed a higher content of total dietary fibre, IFB had the same content of insoluble dietary fibre as TFB (54%), better hydration properties, higher content of glucosinolates (100 mg/100 g d.w.) and (poly)phenols (74.7 mg/100 g d.w.). The prebiotic effect was evaluated in IFB and compared with DBS by in vitro fermentation with human faecal slurries. After 48 h, the short-chain fatty acid (SCFA) production was higher with IFB than with DBS because of the greater presence of both uronic acids, the main component of pectin, and (poly)phenols. These results reveal that novel fibre-rich ingredients—with antioxidant, technological and physiological effects—could be obtained from broccoli stalks by using green extraction methods.

Glucosinolates are an important class of secondary metabolites in Brassicales plants with a critical role in chemical defense. Glucosinolates are chemically inactive but can be hydrolyzed by myrosinases to produce a range of chemically active compounds toxic to herbivores and pathogens, thereby constituting the glucosinolate–myrosinase defense system or the mustard oil bomb. During the evolution, Brassicales plants have developed not only complex biosynthetic pathways for production of a large number of glucosinolate structures but also different classes of myrosinases that differ in catalytic mechanisms and substrate specificity. Studies over the past several decades have made important progress in the understanding of the cellular and subcellular organization of the glucosinolate–myrosinase system for rapid and timely detonation of the mustard oil bomb upon tissue damage after herbivore feeding and pathogen infection. Progress has also been made in understanding the mechanisms that herbivores and pathogens have evolved to counter the mustard oil bomb. In this review, we summarize our current understanding of the function and organization of the glucosinolate–myrosinase system in Brassicales plants and discuss both the progresses and future challenges in addressing this complex defense system as an excellent model for analyzing plant chemical defense.

Glucosinolate transporters (GTRs) are part of the nitrate/peptide transporter (NPF) family, members of which also transport specialized secondary metabolites as substrates. Glucosinolates are defense compounds derived from amino acids. We selected 4-methylthiobutyl (4MTB) and indol-3-ylmethyl (I3M) glucosinolates to study how GTR1 from Arabidopsis thaliana transports these substrates in computational simulation approaches. The designed pipeline reported here includes massive docking of 4MTB and I3M in an ensemble of GTR1 conformations (in both inward and outward conformations) extracted from molecular dynamics simulations, followed by clustered and substrate–protein interactions profiling. The identified key residues were mutated, and their role in substrate transport was tested. We were able to identify key residues that integrate a major binding site of these substrates, which is critical for transport activity. In silico approaches employed here represent a breakthrough in the plant transportomics field, as the identification of key residues usually takes a long time if performed from a purely wet-lab experimental perspective. The inclusion of structural bioinformatics in the analyses of plant transporters significantly speeds up the knowledge-gaining process and optimizes valuable time and resources.

An important factor of current climate change is water availability, with both droughts and flooding becoming more frequent. Effects of individual stresses on plant traits are well studied, although less is known about the impacts of sequences of different stresses. We used savoy cabbage to study the consequences of control conditions (well-watered) versus continuous drought versus drought followed by soil flooding and a potential recovery phase on shoot growth and leaf metabolism. Under continuous drought, plants produced less than half of the shoot biomass compared to controls, but had a >20% higher water use efficiency. In the soil flooding treatment, plants exhibited the poorest growth performance, particularly after the “recovery” phase. The carbon-to-nitrogen ratio was at least twice as high, whereas amino acid concentrations were lowest in leaves of controls compared to stressed plants. Some glucosinolates, characteristic metabolites of Brassicales, showed lower concentrations, especially in plants of the flooding treatment. Stress-specific investment into different amino acids, many of them acting as osmolytes, as well as glucosinolates, indicate that these metabolites play distinct roles in the responses of plants to different water availability conditions. To reduce losses in crop production, we need to understand plant responses to dynamic climate change scenarios.

Glucoraphasatin (GRH) is a specific aliphatic glucosinolate (GSL) that is only abundant in radish (Raphanus sativus L.). The gene expression regulating GRH biosynthesis in radish is still poorly understood. We employed a total of 59 radish accessions to analyze GSL profiles and showed that GRH was specific and predominant among the aliphatic GSLs in radish roots. We selected five accessions roots with high, moderate and low GSL biosynthesis, respectively, to conduct a comparative transcriptome analysis and the qRT-PCR of the biosynthesis genes for aliphatic GSLs. In this study, among all the accessions tested, roots with the accession RA157-74 had a high GRH content and showed a significant expression of the aliphatic GSL biosynthesis genes. We defined the genes involved in the GRH biosynthesis process and found that they were regulated by a transcription factor (RSG00789) at the MYB29 locus in radish roots. We found 13 aliphatic GSL biosynthesis genes regulated by the RSG00789 gene in the GRH biosynthesis pathway.

In the last decades, glucosinolates (GLs), precursors of isothiocyanates (ITCs), have been studied mostly for their chemopreventive and chemotherapeutic properties. The aim of our research was to study the antiproliferative effect of 4-(α-L-rhamnopyranosyloxy) benzyl glucosinolate (glucomoringin; GMG) bioactivated by myrosinase enzyme to form the corresponding isothiocyanate 4-(α-L-rhamnopyranosyloxy) benzyl C (moringin) in SH-SY5Y human neuroblastoma cells. We found that moringin significantly reduced SH-SY5Y cell growth in a time and concentration-dependent (p < 0.05, 0.01, and 0.001 vs. ctrl, after treatment with 16.4 µM moringin for 24, 48, and 72 h, respectively) manner through a mechanism involving the activation of apoptotic machinery. In addition, it altered the normal progression of cells through the cell cycle, increasing the cell population in both G2 and S phases, as well as decreasing that in the G1 phase. Studying the drug mechanism of action, we found that moringin was able to increase the expression of p53, p21, and Bax at both the protein and transcriptional level. Moreover, exposure of SH-SY5Y cells to moringin significantly increased the gene expression of both caspase 3 and 9 and enhanced their cleavage, thereby initiating an intrinsic apoptotic cascade. Finally, moringin inhibited nuclear translocation of NF-κB. Our study demonstrates the ability of moringin to reduce the growth of SH-SY5Y cells and reveals its mechanism of action, suggesting its promising role as an anticancer drug.

Sclerotinia stem rot (white mold), caused by the fungus Sclerotinia sclerotiorum, is a serious disease of Brassica crops worldwide. Despite considerable progress in investigating plant defense mechanisms against this pathogen, which have revealed the involvement of glucosinolates, the host⁻pathogen interaction between cabbage (Brassica oleracea) and S. sclerotiorum has not been fully explored. Here, we investigated glucosinolate profiles and the expression of glucosinolate biosynthesis genes in white-mold-resistant (R) and -susceptible (S) lines of cabbage after infection with S. sclerotiorum. The simultaneous rise in the levels of the aliphatic glucosinate glucoiberverin (GIV) and the indolic glucosinate glucobrassicin (GBS) was linked to white mold resistance in cabbage. Principal component analysis showed close association between fungal treatment and cabbage GIV and GBS contents. The correlation analysis showed significant positive associations between GIV content and expression of the glucosinolate biosynthesis genes ST5b-Bol026202 and ST5c-Bol030757, and between GBS content and the expression of the glucosinolate biosynthesis genes ST5a-Bol026200 and ST5a-Bol039395. Our results revealed that S. sclerotiorum infection of cabbage induces the expression of glucosinolate biosynthesis genes, altering the content of individual glucosinolates. This relationship between the expression of glucosinolate biosynthesis genes and accumulation of the corresponding glucosinolates and resistance to white mold extends the molecular understanding of glucosinolate-negotiated defense against S. sclerotiorum in cabbage.

Ringspot, caused by the fungus Mycosphaerella brassicicola, is a serious disease of Brassica crops worldwide. Despite noteworthy progress to reveal the role of glucosinolates in pathogen defense, the host–pathogen interaction between cabbage (Brassica oleracea) and M. brassicicola has not been fully explored. Here, we investigated the glucosinolate profiles and expression of glucosinolate biosynthesis genes in the ringspot-resistant (R) and susceptible (S) lines of cabbage after infection with M. brassicicola. The concomitant rise of aliphatic glucoiberverin (GIV) and indolic glucobrassicin (GBS) and methoxyglucobrassicin (MGBS) was linked with ringspot resistance in cabbage. Pearson’s correlation and principle component analysis showed a significant positive association between GIV contents and the expression of the glucosinolate biosynthesis gene ST5b-Bol026202 and between GBS contents and the expression of the glucosinolate biosynthesis gene MYB34-Bol017062. Our results confirmed that M. brassicicola infection induces the expression of glucosinolate biosynthesis genes in cabbage, which alters the content of individual glucosinolates. This link between the expression of glucosinolate biosynthesis genes and the accumulation of their respective glucosinolates with the resistance to ringspot extends our molecular sense of glucosinolate-negotiated defense against M. brassicicola in cabbage.

Methyl jasmonate (MeJA), synthesized in the jasmonic acid (JA) pathway, has been found to upregulate glucosinolate (GS) biosynthesis in plant species of the Brassicaceae family. Exogenous application of MeJA has shown to increase tissue GS concentrations and the formation of myrosinase-mediated GS hydrolysis products (GSHPs). In vitro and in vivo assays have demonstrated the potential health-promoting effects of certain GSHPs. MeJA is also known to elicit and induce genes associated with defense mechanisms to insect herbivory in Brassica species. To investigate the relationship between MeJA-induced GS biosynthesis and insect defense, three treatments were applied to "Red Russian" kale (Brassicae napus var. pabularia) seedlings: (1) a 250 μM MeJA leaf spray treatment; (2) leaf infestation with larvae of the cabbage looper (Trichoplusia ni (Hübner)); (3) control treatment (neither larval infestation nor MeJA application). Samples of leaf tissue from the three treatments were then assayed for changes in GS and GSHP concentrations, GS gene biosynthesis expression, and myrosinase activity. Major differences were observed between the three treatments in the levels of GS accumulation and GS gene expression. The insect-damaged samples showed significantly lower aliphatic GS accumulation, while both MeJA and T. ni infestation treatments induced greater accumulation of indolyl GS. The gene expression levels of CYP81F4, MYB34, and MYB122 were significantly upregulated in samples treated with MeJA and insects compared to the control group, which explained the increased indolyl GS concentration. The results suggest that the metabolic changes promoted by MeJA application and the insect herbivory response share common mechanisms of induction. This work provides potentially useful information for kale pest control and nutritional quality. [ABSTRACT FROM AUTHOR]

The genetic basis of the wide variation for nutritional traits in Brassica rapa is largely unknown. A new Recombinant Inbred Line (RIL) population was profiled using High Performance Liquid Chromatography (HPLC) and Nuclear Magnetic Resonance (NMR) analysis to detect quantitative trait loci (QTLs) controlling seed tocopherol and seedling metabolite concentrations. RIL population parent L58 had a higher level of glucosinolates and phenylpropanoids, whereas levels of sucrose, glucose and glutamate were higher in the other RIL population parent, R-o-18. QTL related to seed tocopherol (α-, β-, γ-, δ-, α-⁄γ- and total tocopherol) concentrations were detected on chromosomes A3, A6, A9 and A10, explaining 11%–35% of the respective variation. The locus on A3 co-locates with the BrVTE1gene, encoding tocopherol cyclase. NMR spectroscopy identified the presence of organic/amino acid, sugar/glucosinolate and aromatic compounds in seedlings. QTL positions were obtained for most of the identified compounds. Compared to previous studies, novel loci were found for glucosinolate concentrations. This work can be used to design markers for marker-assisted selection of nutritional compounds in B. rapa.

Isothiocyanates (ITCs), the biologically important glucosinolate breakdown products, can present health-promoting effects, play an important role in plant defense and affect plant cellular mechanisms. Here, we evaluated the biological effects of ITCs on Arabidopsis thaliana by assessing growth parameters after long-term exposure to low concentrations of aliphatic and aromatic ITCs, ranging from 1 to 1000 μM. Treatment with the aliphatic allylisothiocyanate (allyl-ITC) led to a significant reduction of root length and fresh weight in a dose-dependent manner and affected the formation of lateral roots. To assess the importance of a hormonal crosstalk in the allyl-ITC-mediated growth reduction, the response of auxin and ethylene mutants was investigated, but our results did not allow us to confirm a role for these hormones. Aromatic ITCs generally led to a more severe growth inhibition than the aliphatic allyl-ITC. Interestingly, we observed a correlation between the length of their side chain and the effect these aromatic ITCs caused on Arabidopsis thaliana, with the greatest inhibitory effect seen for 2-phenylethyl-ITC. Root growth recovered when seedlings were removed from exposure to ITCs. [ABSTRACT FROM AUTHOR]

Glucosinolates, a class of secondary metabolites, mainly found in Brassicaceae, are affected by the changing environment. This review is focusing on the physiological significance of glucosinolates and their hydrolysis products in the plant response to different abiotic stresses. Special attention is paid to the crosstalk between some of the physiological processes involved in stress response and glucosinolate metabolism, with the resulting connection between both pathways in which signaling mechanisms glucosinolate may act as signals themselves. The function of glucosinolates, further than in defense switching, is discussed in terms of alleviating pathogen attack under abiotic stress. The fact that the exogenous addition of glucosinolate hydrolysis products may alleviate certain stress conditions through its effect on specific proteins is described in light of the recent reports, but the molecular mechanisms involved in this response merit further research. Finally, the transient allocation and re-distribution of glucosinolates as a response to environmental changes is summarized.