Search

This study investigated the effect of salicylic acid (SA) treatment on preserving the color and nutritional quality of broccoli during postharvest cold storage. The results demonstrated that SA treatment significantly delayed the yellowing process, increased chlorophyll content, −a*/b* value, quantum yield (Fv/Fm), and fluorescence decline ratio (Rfd) and decreased L* value and yellowing index compared with untreated control. Meanwhile, the losses of glucoraphanin (GRA), glucobrassicin (GBS), sulforaphane (SFN), indole-3-methanol (I3C), and ascorbic acid (AsA) were obviously alleviated in the treated samples, and the accumulation of total phenols and total flavonoids was significantly increased. In addition, the total antioxidant capacity (T-AOC) of the treated samples was improved remarkably and the content of malondialdehyde (MDA) was significantly reduced. Multivariate statistical analysis visualized the distribution of sensory and nutritional variables in both groups of samples, further demonstrating that SA treatment was more effective in preserving GRA and AsA and effectively induced an improvement of the antioxidant capacity.

Abstract Background Wasabi, a Brassicaceae member, is well-known for its unique pungent and hot flavor which is produced from glucosinolate (GSL) degradation. Myrosinase (MYR) is a principle enzyme catalyzing the primary conversion of GSLs to GSL hydrolysis products (GHPs) which is responsible for plant defense system and food quality. Due to the limited information in relation to MYRs present in wasabi (Wasabia japonica M.), this study aimed to identify the MYR isogenes in W. japonica and analyze their roles in relation to GSL metabolism. Results In results, WjMYRI-1 was abundantly expressed in all organs, whereas WjMYRI-2 showed only trace expression levels. WjMYRII was highly expressed in the aboveground tissues. Interestingly, WjMYRII expression was significantly upregulated by certain abiotic factors, such as methyl jasmonate (more than 40-fold in petioles and 15-fold in leaves) and salt (tenfold in leaves). Young leaves and roots contained 97.89 and 91.17 µmol‧g−1 of GSL, whereas less GSL was produced in mature leaves and petioles (38.36 and 44.79 µmol‧g−1, respectively). Similar pattern was observed in the accumulation of GHPs in various plant organs. Notably, despite the non-significant changes in GSL production, abiotic factors treated samples enhanced significantly GHP content. Pearson’s correlation analysis revealed that WjMYRI-1 expression significantly correlated with GSL accumulation and GHP formation, suggesting the primary role of WjMYRI-1-encoding putative protein in GSL degradation. In contrast, WjMYRII expression level showed no correlation with GSL or GHP content, suggesting another physiological role of WjMYRII in stress-induced response. Conclusions In conclusions, three potential isogenes (WjMYRI-1, WjMYRI-2, and WjMYRII) encoding for different MYR isoforms in W. japonica were identified. Our results provided new insights related to MYR and GSL metabolism which are important for the implications of wasabi in agriculture, food and pharmaceutical industry. Particularly, WjMYRI-1 may be primarily responsible for GSL degradation, whereas WjMYRII (clade II) may be involved in other regulatory pathways induced by abiotic factors.

Abstract Background Brassicas (Brassicaceae) are recognized as excellent sources of nutrients and bioactive compounds. Among these, wild turnip (Brassica rapa L.), holds significant promising nutritional properties owed to its abundant glucosinolates and phenolic compounds. To enhance its potential values, the application of elicitors is crucial and good strategy prompting an enrichment in the concentration of phytochemicals, as well established in other relevant Brassicas, such as broccoli. While the responses triggered by certain elicitors such as salicylic acid, methyl jasmonate, or chitosan are widely documented, little is known about the impact of electrolyzed water, an economically viable elicitor. Through elicitation strategies, the aim of this work was to unravel insights into enhancing the phytochemical content of wild turnip sprouts for potential use as healthy food, comparing with well-studied broccoli as control of the experiments. Results Our findings revealed that wild turnip exhibited a notable higher glucosinolate (GSL) contents (487–712 mg 100 g−1 D.W.), than in broccoli sprouts. Furthermore, the use of electrolyzed water (2 vol.) boosted the accumulation of glucosinolates with significant increase up to twofolds the content. Specifically, treatments with salicylic acid (250 μM) and electrolyzed water (2 vol.) favored the significant increase of mainly aliphatic GSL (progoitrin, PRO; gluconapin, GNA; glucobrassicin, GBN). On the other hand, natural antioxidants such as of the characteristic acylated cyanidins present in wild turnip sprouts were not affected by the elicitor treatments, indicative of higher tolerance to oxidative stress in wild turnip. Conclusions These observations underlined the potential of using electrolyzed water in wild turnips as elicitor for GSL-enriched food ingredients. Further studies will be necessary to align with the broader goal of evaluating abiotic and biotic factors affecting the phytochemical composition in mature organs not only in germinating seeds and sprouts, for agricultural performance for quality and healthy foods purposes. Graphical Abstract

Glucosinolates (GSLs) are a group of nitrogen- and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial activity, resistance to insect attack, stress tolerance, and human anti-cancer effects. As a sulfur-containing compound, glutathione has a strong connection with GSLs biosynthesis as a sulfur donor or redox system, and exists in reduced (glutathione; GSH) and oxidized (glutathione disulfide; GSSG) forms. However, the mechanism of GSH regulating GSLs biosynthesis remainds unclear. Hence, the exogenous therapy to pakchoi under normal growth condition and sulfur deficiency condition were conducted in this work to explore the relevant mechanism. The results showed that exogenous application of buthionine sulfoximine, an inhibitor of GSH synthesis, decreased the transcript levels of GSLs synthesis-related genes and transcription factors, as well as sulfur assimilation-related genes under the normal growth condition. Application of exogenous GSH inhibited the expression of GSLs synthesis- and sulfur assimilation-related genes under the normal condition, while the GSLs biosynthesis and the sulfur assimilation pathway were activated by exogenous application of GSH when the content of GSH in vivo of plants decreased owing to sulfur deficiency. Moreover, exogenous application of GSSG increased the transcript levels of GSLs synthesis- and sulfur assimilation-related genes under the normal growth condition and under sulfur deficiency. The present work provides new insights into the molecular mechanisms of GSLs biosynthesis underlying glutathione regulation.

Background: Wasabi, a Brassicaceae member, is well-known for its unique pungent and hot flavor which is produced from glucosinolate (GSL) degradation. Myrosinase (MYR) is a principle enzyme catalyzing the primary conversion of GSLs to GSL hydrolysis products (GHPs) which is responsible for plant defense system and food quality. Due to the limited information in relation to MYRs present in wasabi (Wasabia japonica M.), this study aimed to identify the MYR isogenes in W. japonica and analyze their roles in relation to GSL metabolism. Results: In results, WjMYRI-1 was abundantly expressed in all organs, whereas WjMYRI-2 showed only trace expression levels. WjMYRII was highly expressed in the aboveground tissues. Interestingly, WjMYRII expression was significantly upregulated by certain abiotic factors, such as methyl jasmonate (more than 40-fold in petioles and 15-fold in leaves) and salt (tenfold in leaves). Young leaves and roots contained 97.89 and 91.17 µmol‧g−1 of GSL, whereas less GSL was produced in mature leaves and petioles (38.36 and 44.79 µmol‧g−1, respectively). Similar pattern was observed in the accumulation of GHPs in various plant organs. Notably, despite the non-significant changes in GSL production, abiotic factors treated samples enhanced significantly GHP content. Pearson's correlation analysis revealed that WjMYRI-1 expression significantly correlated with GSL accumulation and GHP formation, suggesting the primary role of WjMYRI-1-encoding putative protein in GSL degradation. In contrast, WjMYRII expression level showed no correlation with GSL or GHP content, suggesting another physiological role of WjMYRII in stress-induced response. Conclusions: In conclusions, three potential isogenes (WjMYRI-1, WjMYRI-2, and WjMYRII) encoding for different MYR isoforms in W. japonica were identified. Our results provided new insights related to MYR and GSL metabolism which are important for the implications of wasabi in agriculture, food and pharmaceutical industry. Particularly, WjMYRI-1 may be primarily responsible for GSL degradation, whereas WjMYRII (clade II) may be involved in other regulatory pathways induced by abiotic factors. [ABSTRACT FROM AUTHOR]

Radical difunctionalization of aliphatic alkynes provides direct access to valuable multi‐substituted alkenes, but achieving a high level of chemo‐ and stereo‐control remains a formidable challenge. Herein a novel photoredox neutral alkyne di‐functionalization is reported through functional group migration followed by a radical‐polar crossover and energy transfer‐enabled stereoconvergent isomerization of alkenes. In this sequence, a hydroxyalkyl and an aryl group are incorporated concomitantly into an alkyne, leading to diversely functionalized E‐allyl alcohols. The scope of alkynes is noteworthy, and the reaction tolerates aliphatic alkynes containing hydrogen donating C─H bonds that are prone to intramolecular hydrogen atom transfer. The protocol features broad functional group compatibility, high product diversity, and exclusive chemo‐ and stereoselectivity, thus providing a practical strategy for the elusive radical di‐functionalization of unactivated alkynes. [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. [ABSTRACT FROM AUTHOR]

Non‐native annual grasses have invaded western rangelands in the United States, and novel approaches are needed to supplement existing management strategies. The aim of this study was to investigate biofumigation, the use of Brassicaceae products to suppress weeds, as a control for two non‐native annual grasses (cheatgrass, Bromus tectorum and ventenata, Ventenata dubia) and its effects on two dominant native perennial grasses (bluebunch wheatgrass, Pseudoroegneria spicata and Idaho fescue, Festuca idahoensis). We tested the effect of the biofumigant Brassica juncea (brown mustard), applied as seed meal and mulch, on germination metrics of the four grass species in Petri dishes. Germination metrics included emergence and viability, time to cotyledon and radicle emergence and their lengths at 14 days after sowing. Impacts on emergence and viability were assessed using a binomial mixed effects model, while time to cotyledon and radicle emergence and lengths were assessed using linear mixed effects models. Seed meal reduced emergence and viability at lower application rates for V. dubia and F. idahoensis than the other two species. Mulch did not consistently reduce emergence or viability. P. spicata was the least inhibited by the biofumigants. When using seed meal, radicle emergence and length were inhibited in B. tectorum, V. dubia and F. idahoensis and cotyledon emergence and length were inhibited for all. The mulch did not impact these metrics consistently and may not be a viable management tool. The use of seed meal biofumigant to suppress undesired annual grasses in rangelands seems promising, but response is species‐specific. [ABSTRACT FROM AUTHOR]

In this paper, we take a historical perspective by going back to Verschaffelt's landmark study published in 1910, in which he found that glucosinolates were used as token stimuli by larvae of Pieris butterflies, specialist feeders on plants in the family Brassicaceae. This classic discovery provided key evidence for Fraenkel (Science 129:1466–1470, 1959) to elaborate on the function of secondary plant substances and for Ehrlich and Raven (Evolution 18:586–608, 1964) to put forward the hypothesis of insect–plant coevolution. The discovery by Schoonhoven (Kon Nederl Akad Wetensch Amsterdam Proc Ser C70:556–568, 1967) of taste neurons highly sensitive to glucosinolates in Pieris brassicae was an important milestone in elucidating the chemosensory basis of host-plant specialization. The molecular basis of glucosinolate sensitivity was elucidated recently (Yang et al., PLoS Genet 17, 2021) paving the way to unravel the evolution of gustatory receptors tuned to glucosinolates that are crucial for host-plant selection of Pieris butterflies. We propose a hypothetical model for the evolution of labeled-line neurons tuned to token stimuli. [ABSTRACT FROM AUTHOR]