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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]

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]

The present work studies the composting effects on the chemical characteristics of bio‐oil produced by pyrolysis of sisal residue. Three systems were composted with sisal residue proportions to sisal fiber powder of 100:0, 90:10, and 75:25, respectively. The systems showed reductions of 33%–48% (extractive), 70%–80% (hemicellulose), and 80%–90% (cellulose) after composting. An increase in lignin content was observed in all systems. The pyrolysis of the composted systems was performed at 450°C and 550°C. At both temperatures, this process was selective in producing a large concentration of hydrocarbons (>160% increase), mainly alkanes and alkenes, reducing the concentrations of ketones, aldehydes, and phenolics (>50%) and eliminating esters, furans, and acetic acid to composted biomasses. The higher temperature favored aromatics and cyclic hydrocarbon production from the pyrolysis of composted samples. In addition to these results, composting helped reduce the oxygenated bio‐oil species by approximately 44%–75% at the lowest and ~69% at the highest temperatures. These results indicate that composted sisal residue can produce bio‐oils that are more suitable for biorefineries since they are rich in aliphatic hydrocarbons and non‐oxygenated species. [ABSTRACT FROM AUTHOR]

Summary: Microgreens grow best under light‐emitting diodes (LED), an artificial light source. In this study, LED lights (red, blue and far‐red) were tested on brassica microgreens to see if they induced an increase in bioactive compounds (glucosinolates and phenolics). In vitro digestion also measured bioavailable bioactive compounds in the intestinal phase. LED lights (red, blue and far‐red) were applied for 6 h in storage at 5 °C and 85% RH for 5 days on cabbage (Brassica oleracea), radish (Raphanus sativus) and rocket (Eruca vesicaria (L.) Cav). Red light significantly enhanced ascorbic acid, total phenols, kaempferol and quercetin glycoside concentrations in all three Brassica microgreens and antioxidant activities. Exposure to red LED light increased 4‐methoxyglucobrassicin (cabbage), glucoraphenin (radish), glucoraphanin A and glucoerucin (rocket). Red light stress may have resulted in secondary metabolite production in immature plants. An in vitro digestion showed higher concentrations of phenolic compounds, glucosinolate components and antioxidants in the intestinal phase. Red LED light is recommended as a postharvest treatment for improving cabbage, rocket and radish bioactive compounds. [ABSTRACT FROM AUTHOR]

Brassicaceae plants have the glucosinolate–myrosinase defense system, jointly active against herbivory. However, constitutive glucosinolate (GLS) defense is observed to occur at levels that do not deter all insects from feeding. That prompts the question of why Brassicaceae plants have not evolved a higher constitutive defense. The answer may lie in the contrasting relationship between plant defense and host plant preference of specialist and generalist herbivores. GLS content increases a plant's susceptibility to specialist insects. In contrast, generalists are deterred by the plant GLSs. Although GLSs can attract the natural enemies (predators and parasitoids) of these herbivores, enemies can reduce herbivore pressure to some extent only. So, plants can be overrun by specialists if GLS content is too high, whereas generalists can invade the plants if it is too low. Therefore, an optimal constitutive plant defense can minimize the overall herbivore pressure. To explain the optimal defense theoretically, we model the contrasting host selection behavior of insect herbivores and the emergence of their natural enemies by non‐autonomous ordinary differential equations, where the independent variable is the plant GLS concentration. From the model, we quantify the optimal amount of GLSs, which minimizes total herbivore (specialists and generalists) pressure. That quite successfully explains the evolution of constitutive defense in plants from the perspective of optimality theory. [ABSTRACT FROM AUTHOR]

BACKGROUND: Multiple and simultaneous attacks by pathogens and insect pests frequently occur in nature. Plants respond to biotic stresses by activating distinct defense mechanisms, but little is known about how plants cope with multiple stresses. The focus of this study was the combined interaction of fungal infection caused by Leptosphaeria maculans (synonym Plenodomus lingam) and arthropod infestation by the diamondback moth (Plutella xylostella) in oilseed rape (Brassica napus). We hypothesized that infection by the fungal pathogen L. maculans could alter oilseed rape palatability to P. xylostella‐chewing caterpillars. Feeding preference tests were complemented with analyses of defense gene transcription, and levels of glucosinolates (GLSs) and volatile organic compounds (VOCs) in L. maculans‐inoculated and non‐inoculated (control) leaves to determine possible causes of larval choice. RESULTS: Caterpillars preferred true leaves to cotyledons, hence true leaves were used for further experiments. True leaves inoculated with L. maculans were more palatable to caterpillars over control leaves during the early stage of infection at 3 days post inoculation (dpi), but this preference disappeared in the later stages of infection at 7 dpi. In parallel, genes involved in the salicylic acid and ethylene pathways were up‐regulated in L. maculans‐inoculated leaves at 3 and 7 dpi; L. maculans increased the level of total aliphatic GLSs, specifically glucobrassicanapin, and decreased the level of glucoiberin at 3 dpi and altered the content of specific VOCs. A group of 55 VOCs with the highest variability between treatments was identified. CONCLUSION: We suggest that the P. xylostella preference for L. maculans‐inoculated leaves in the early stage of disease development could be caused by the underlying mechanisms leading to changes in metabolic composition. Further research should pinpoint the compounds responsible for driving larval preference and evaluate whether the behavior of the adult moths, i.e. the stage that makes the first choice regarding host plant selection in field conditions, correlates with our results on larval host acceptance. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The precipitation and deposition of waxes in high waxy crude oil often result in the low throughput and clogging of pipeline. Adding polymers is a practical approach to solve these problems. In this study, poly(styrene-co-docosyl maleate) s (PSDMs) were synthesized by reversible addition-fragmentation chain transfer polymerization. The chemical structure and molecular weight of copolymers were characterized using Fourier infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The ratio of phenyl to aliphatic branches varies from 10:8 to 25:8. The crystallization and morphology of waxes in model oil were investigated by x-ray diffraction, differential scanning calorimetry, and polarized light microscopy. The cold flow behaviors of crude oil were evaluated by rheological methods. With the increase of the ratio of phenyl to aliphatic branches, the crystallinity, viscosity, and yield stress of crude oil first increase and then decrease. In the presence of PSDM-2, the crystallinity and enthalpy of phase transition (H) are reduced by 44.2% and 48.9%. Thus, the pour point, viscosity, and yield stress of crude oil are reduced by 6.0°C, 76.8% and 77.4%, respectively. Therefore, welldefined PSDMs are promising to be remarkable flow improvers for waxy crude oils. [ABSTRACT FROM AUTHOR]

Summary: Glucosinolates (GSLs), compounds with potential chemo‐preventative properties, can be affected by pre‐ and post‐harvest processes. Therefore, monitoring their content is important for the food and agricultural industries. This study evaluates the application of mid‐infrared (MIR) spectroscopy for the determination of GSLs in commercial broccoli (Brassica oleracea var. italica). Broccoli (n = 53) from different varieties were analysed using MIR spectroscopy and high‐performance liquid chromatography to develop partial least squares models for six individual GLSs, total indolic glucosinolates and total GSLs. The coefficient of determination in cross‐validation (Rcv2) of 0.50–0.78 whereas residual predictive deviation (RPD) values of 1.35–2.19 for different GSLs. Cross‐validation models developed using Tenderstem® broccoli yielded an Rcv2 of 0.41–0.91 and an RPD of 0.81–2.97. This study showed that MIR spectroscopy can be considered for the determination of some broccoli GSLs. Differences in the loadings between the models demonstrated that variations in broccoli composition can influence the cross‐validation models for GSLs. [ABSTRACT FROM AUTHOR]

Plant responses against pathogens are influenced by growth immunity tradeoff, which ensure the best use of limited resources. We study how the immobilization of carbon resources and the induction of defensive responses (glucosinolates, phenolic compounds, stomatal closure) can influence the biomass of two Brassica oleracea lines, differing in their resistance, after infection with Xanthomonas campestris pv. campestris. Potentially, the growth immunity tradeoff can be influenced by the activation of all these processes. However, on the contrary of which is normally stated, our results suggest that the loss of biomass caused by pathogen infection is mainly due to the differential accumulation of starch and the immobilization of sugars rather than the reallocation of resources to synthesize secondary metabolites. Moreover, resistance may be related to the effectiveness of the tradeoff, since the resistant line immobilizes resources more efficiently than the susceptible one. Both inbred lines show a different phytohormones profile, which support the hypothesis that they are employing different strategies to defend themselves against the pathogen. This study emphasizes the key role of the primary metabolism in the defence strategies of plants against pathogens. Summary statement: In this work we have proved that the loss of biomass in Brassica oleracea caused by pathogen infection of Xanthomonas campestris pv. campestris is due to the differential accumulation of starch and the immobilization of sugar resources rather than the synthesis of secondary metabolites. [ABSTRACT FROM AUTHOR]

Specialized metabolites are a structurally diverse group of naturally occurring compounds that facilitate plant–environment interactions. Their synthesis and maintenance in plants is overall a resource‐demanding process that occurs at the expense of growth and reproduction and typically incurs several costs. Evidence emerging on different specialized compounds suggests that they serve multiple auxiliary functions to influence and moderate primary metabolism in plants. These new functionalities enable them to mediate trade‐offs from defenses to growth and also to offset their production and maintenance costs in plants. Recent research on glucosinolates (GSLs), which are specialized metabolites of Brassicales, demonstrates their emerging multifunctionalities to fine‐tune plant growth and development under variable environments. Herein, we present findings from the septennium on individual GSLs and their catabolites (GHPs) per se, that work as mobile signals within plants to mediate precise regulations of their primary physiological functions. Both GSLs and GHPs calibrate growth‐defense trade‐off interactions either synergistically or directly when they function as storage compounds, abiotic stress alleviators, and one‐to‐one regulators of growth pathways in plants. We finally summarize the overall lessons learned from GSLs and GHPs as a model and raise the most pressing questions to address the molecular‐genetic intricacies of specialized metabolite‐based trade‐offs in plants. Summary Statement: Specialized metabolites boost fitness and adjust trade‐offs in plants under variable environments. Emerging literature has described novel functions in Brassicales specific glucosinolates and their hydrolysis products that have not received adequate attention so far. These auxiliary functionalities enable them to coordinate and fine‐tune primary aspects of plant growth and development under changing environments. Several adaptive scenarios should back these functional diversities in glucosinolates and their catabolites including their metabolic cost‐effectiveness, novel recycling's, and signaling robustness to timely and spatially optimize fitness outputs in plants. [ABSTRACT FROM AUTHOR]

SUMMARY: Phenylpropanoids are specialized metabolites derived from phenylalanine. Glucosinolates are defense compounds derived mainly from methionine and tryptophan in Arabidopsis. It was previously shown that the phenylpropanoid pathway and glucosinolate production are metabolically linked. The accumulation of indole‐3‐acetaldoxime (IAOx), the precursor of tryptophan‐derived glucosinolates, represses phenylpropanoid biosynthesis through accelerated degradation of phenylalanine ammonia lyase (PAL). As PAL functions at the entry point of the phenylpropanoid pathway, which produces indispensable specialized metabolites such as lignin, aldoxime‐mediated phenylpropanoid repression is detrimental to plant survival. Although methionine‐derived glucosinolates in Arabidopsis are abundant, any impact of aliphatic aldoximes (AAOx) derived from aliphatic amino acids such as methionine on phenylpropanoid production remains unclear. Here, we investigate the impact of AAOx accumulation on phenylpropanoid production using Arabidopsis aldoxime mutants, ref2 and ref5. REF2 and REF5 metabolize aldoximes to respective nitrile oxides redundantly, but with different substrate specificities. ref2 and ref5 mutants have decreased phenylpropanoid contents due to the accumulation of aldoximes. As REF2 and REF5 have high substrate specificity toward AAOx and IAOx, respectively, it was assumed that ref2 accumulates AAOx, not IAOx. Our study indicates that ref2 accumulates both AAOx and IAOx. Removing IAOx partially restored phenylpropanoid content in ref2, but not to the wild‐type level. However, when AAOx biosynthesis was silenced, phenylpropanoid production and PAL activity in ref2 were completely restored, suggesting an inhibitory effect of AAOx on phenylpropanoid production. Further feeding studies revealed that the abnormal growth phenotype commonly observed in Arabidopsis mutants lacking AAOx production is a consequence of methionine accumulation. Significance Statement: Aliphatic aldoximes are precursors of various specialized metabolites including defense compounds. This study reveals that aliphatic aldoximes repress phenylpropanoid production and that altered methionine metabolism affects plant growth and development. As phenylpropanoids include vital metabolites such as lignin, a major sink of fixed carbon, this metabolic link may contribute to available resource allocation during defense. [ABSTRACT FROM AUTHOR]

BACKGROUD: Two‐component histidine kinase (HK) phosphorelay signaling systems play important roles in differentiation, virulence, secondary metabolite production and response to environmental signals. Allyl isothiocyanate (A‐ITC) is a hydrolysis product of glucosinolates with excellent antifungal activity. Our previous study indicated that the mycelial growth of Cochliobolus heterostrophus was significantly hindered by A‐ITC. However, the function of HK in regulating A‐ITC sensitivity was not clear in C. heterostrophus, the causal agent of Southern corn leaf blight. RESULTS: In this study, the role of HKs was investigated in C. heterostrophus. Deletion of the HK coding gene ChNIK1 resulted in dramatically increased sensitivity of C. heterostrophus to A‐ITC. In addition, ΔChnik1 mutant exhibited significantly decreased conidiation and increased sensitivity to NaCl, KCl, tebuconazole and azoxystrobin, but deletion of the other five HK genes did not affect the A‐ITC sensitivity of C. heterostrophus. ChSLN1, ChNIK4, ChNIK8 and ChMAK2 are essential for conidiation and response to H2O2 and sodium dodecyl sulfate. However, deletion of NIKs had on effect on significant virulence. CONCLUSION: Our findings demonstrate that the HKs play different roles in A‐ITC sensitivity in C. heterostrophus. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Mustard seeds have been used since ancient times contributing great economic value to global agriculture. Canada, one of the world's top producers, grows three main mustard varieties, white /yellow, (Brassica hirta/Sinapis alba), black (Brassica nigra) and Oriental (Brassica juncea). Besides their high protein and lipid content, mustard varieties are a rich source of phenolic compounds. This review will cover mustard seed components including lipids, glucosinolates, and sinapates. The latter are the main phenolic compounds in mustard and include sinapine, sinapic acid and its conversion to canolol. The important bioactivities associated with mustard phenolics, has led to efforts to improve the methods for their extraction. The use of green technology is crucial for producing these phenolics while minimizing any detrimental effects to the environment. The important antioxidant and anticancer activities of these phenolics will also be reviewed. [ABSTRACT FROM AUTHOR]

Plants possess myriad defenses against their herbivores, including constitutive and inducible chemical compounds and regrowth strategies known as tolerance. Recent studies have shown that plant tolerance and resistance are positively associated given they are co‐localized in the same molecular pathway, the oxidative pentose phosphate pathway. However, given that both defensive strategies utilize carbon skeletons from a shared resource pool in the oxidative pentose phosphate pathway there are likely costs in maintaining both resistance‐tolerance strategies. Here we investigate fitness costs in maintaining both strategies by utilizing a double knockout of cyp79B2 and cyp79B3, key enzymes in the biosynthetic process of indole glucosinolates, which convert tryptophan to indole‐3‐acetaldoxime (IAOx) and is further used to produce indole glucosinolates. These mutant plants are devoid of any indole glucosinolates thus reducing plant resistance. Results show that knocking out indole glucosinolate production and thus one of the resistance pathways leads to an approximate 94% increase in fitness compensation shifting the undercompensating wild‐type Columbia‐0 to an overcompensating genotype following damage. We discuss the potential mechanistic basis for the observed patterns. [ABSTRACT FROM AUTHOR]

Cruciferous sprouts and microgreens are a good source of bioactive compounds for human health as they are rich in glucosinolates, polyphenols, carotenoids, and vitamins. Glucosinolates – sulfur‐containing bioactive phytochemicals – have anti‐cancer effects. They mainly exist in cruciferous vegetables. Sulfur is one of the essential elements for plants and is an indispensable component of glucosinolates. This paper summarizes the nutritional value of cruciferous spouts and microgreens, along with the effects of sulfur nutrition on bioactive phytochemical compounds of cruciferous sprouts and microgreens, especially glucosinolates, with the aim of providing information about the dietary effects of cruciferous sprouts and microgreens. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Introduction: Broccoli sprouts have great health and commercial value because they are rich in sulforaphane, a special bioactive compound that helps to prevent chronic diseases, such as cancer and cardiovascular disease. Objective: The aim of this study was to increase the levels of active substances in broccoli sprouts and understand their metabolic mechanisms. Methodology: Metabolomics based on liquid chromatography–tandem mass spectrometry and transcriptome analysis were combined to analyse the enrichment of metabolites in broccoli sprouts treated with cold plasma. Results: After 2 min of cold plasma treatment, the contents of sulforaphane, glucosinolates, total phenols, and flavonoids, as well as myrosinase activity, were greatly improved. Transcriptomics revealed 7460 differentially expressed genes in the untreated and treated sprouts. Metabolomics detected 6739 differential metabolites, including most amino acids, their derivatives, and organic acids. Enrichment analyses of metabolomics and transcriptomics identified the 20 most significantly differentially expressed metabolic pathways. Conclusions: Overall, cold plasma treatment can induce changes in the expression and regulation of certain metabolites and genes encoding active substances in broccoli sprouts. Cold plasma treatment could significantly increase sproud growth and promote the enrichment of active substances in broccoli sprouts. Metabolomic and transcriptomic analyses showed that cold plasma induced changes in the expression and regulation of metabolite and active substance‐encoding genes in sprouts. [ABSTRACT FROM AUTHOR]

Recent discoveries pointed out the importance of the mutual correlation between timing of environmental stress and plant fitness. However, the internal reshaping of plant growth under daily stress sensing, and their metabolic coordination remain to be investigated. Thus, we studied the connection between time of day, growth and defence to understand how plant fitness is affected by diurnal stress inputs.We examined if simulated herbivory (leaf wounding) in the morning, at midday or the evening differentially influence plant defence state vs growth in three crop species of Brassica: broccoli (Brassica oleraceae), turnip greens (B. rapa) and rapeseed (B. napus).The data revealed that plant's tolerance of wounding stress is diurnally regulated in Brassica crops. Trade‐offs between biomass and investment in glucosinolates (GSL) and phenolics were affected by timing of leaf stress. Negative correlations between biomass and induction of defence compounds were found for plants treeated in the morning and evening. However, the correlations were positive for midday treatment. Interestingly, we revealed a new connection between plant growth and changes in aliphatic GSLs and flavonoids in response to wounding.These data suggest that metabolic stress‐dependent circadian oscillations in leaf defences could be one mechanism conferring a competitive advantage to plants to anticipate daily environmental variations by synchronizing them with growth. Moreover, this work provides first insights into how secondary metabolites are linked to growth response in a timing‐related manner. [ABSTRACT FROM AUTHOR]

Summary: Plants often protect themselves from their own bioactive defense metabolites by storing them in less active forms. Consequently, plants also need systems allowing correct spatiotemporal reactivation of such metabolites, for instance under pathogen or herbivore attack.Via co‐expression analysis with public transcriptomes, we determined that the model legume Medicago truncatula has evolved a two‐component system composed of a β‐glucosidase, denominated G1, and triterpene saponins, which are physically separated from each other in intact cells.G1 expression is root‐specific, stress‐inducible, and coregulated with that of the genes encoding the triterpene saponin biosynthetic enzymes. However, the G1 protein is stored in the nucleolus and is released and united with its typically vacuolar‐stored substrates only upon tissue damage, partly mediated by the surfactant action of the saponins themselves. Subsequently, enzymatic removal of carbohydrate groups from the saponins creates a pool of metabolites with an increased broad‐spectrum antimicrobial activity.The evolution of this defense system benefited from both the intrinsic condensation abilities of the enzyme and the bioactivity properties of its substrates. We dub this two‐component system the saponin bomb, in analogy with the mustard oil and cyanide bombs, commonly used to describe the renowned β‐glucosidase‐dependent defense systems for glucosinolates and cyanogenic glucosides. See also the Commentary on this article by Chappell, 239: 456–458. [ABSTRACT FROM AUTHOR]

Ongoing climate change may impact alpine plant populations via both direct effects of increased temperature and climate‐driven changes in interactions between plants and other organisms, such as insect herbivores. Rates of herbivory in high‐elevation environments are predicted to increase with warmer temperatures, which may also lead to changes in morphological and physiological traits that influence plant resistance. Yet, we currently know little about how temperature‐mediated changes in traits will impact alpine plant vulnerability to herbivores, as well as the extent to which populations from high‐elevation environments might need to rapidly adapt to increasing herbivore pressure with rising temperatures.We assessed the effect of experimental warming on the relative vulnerability of populations of the alpine plant Arabis alpina from different elevations to a specialist herbivore. Herbivore performance was measured on plants from nine populations grown in climate chambers at two temperatures, representing low (warm) and high (cold) elevations. We also measured changes in putative drivers of performance: plant phenological, chemical and defence traits. Assuming populations would be adapted to local climates and levels of herbivory, we predicted that low‐elevation populations would be more resistant to herbivores under warmer temperatures than high‐elevation populations.We found reduced performance of a specialist herbivore on A. alpina grown under warm rather than cold conditions, though this effect varied with elevation. Larvae grew faster on high‐elevation populations than low‐elevation populations when grown under warm temperatures, whereas similar growth rates were observed for plants grown under colder temperatures, consistent with plant adaptation to the lower existing herbivore pressure in cold, high‐elevation environments. Regression analyses suggested that polar metabolite variation explained more variance in larval performance than changes in defensive glucosinolates or morphological traits.Our results suggest that although physiological responses to warming may increase the resistance of cold‐adapted plants to herbivory, populations from different elevations may differ in their interactions with herbivores under climate warming. Without genetic adaptation, existing physiological responses of high‐elevation populations to warmer temperatures may leave these populations vulnerable to the increases in herbivore pressure predicted under climate change. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

SUMMARY: Plants developed sophisticated mechanisms to perceive environmental stimuli and generate appropriate signals to maintain optimal growth and stress responses. A fascinating strategy employed by plants is the use of long‐distance mobile signals which can trigger local and distant responses across the entire plant. Some metabolites play a central role as long‐distance mobile signals allowing plants to communicate across tissues and mount robust stress responses. In this review, we summarize the current knowledge regarding the various long‐distance mobile metabolites and their functions in stress response and signaling pathways. We also raise questions with respect to how we can identify new mobile metabolites and engineer them to improve plant health and resilience. [ABSTRACT FROM AUTHOR]

Protein glycation can result in the formation of advanced glycation end products (AGEs), which pose a potential health risk due to their association with diabetic complications. Natural products are a source of drugs discovery and the search for potential natural inhibitors of AGEs is of great significance. Glucosinolates (GSLs) mainly from cruciferous plants have potential antioxidant, anti‐inflammatory, and anti‐glycation activities. In this study, the inhibitory activity of GSLs on bovine serum albumin (BSA) along with its mechanism was investigated by virtual screening and various computational simulation techniques. Virtual screening revealed that 174 GSLs were screened using Maestro based on the glide score and 89% of the compounds were found to have potential anti‐glycation ability with the docking scores less than −5 kcal/mol. Molecular docking showed that the top 10 GSLs were bound to the IIA structural domain of BSA. Among them, glucohesperin (1) and 2‐hydroxyethyl glucosinolate (2) had the lowest docking scores of −9.428 and −9.333 kcal/mol, respectively, reflecting their good binding affinity. Molecular dynamics simulations of 1 (ΔG = −43.46 kcal/mol) and 2 (ΔG = −43.71 kcal/mol) revealed that the complexes of these two compounds with proteins had good stability. Further binding site analysis suggested that the mechanism of inhibition of protein glycation by these two active ingredients might be through competitive hydrogen bonding to maintain the structural integrity of the protein, thus inhibiting glycation reaction. Moreover, the ADMET values and CYP450 metabolism prediction data were within the recommended values. Therefore, it can be concluded that 1 and 2 may act as potential anti‐glycation agents. [ABSTRACT FROM AUTHOR]

For adaptation to ever‐changing environments, plants have evolved elaborate metabolic systems coupled to a regulatory network for optimal growth and defense. Regulation of plant secondary metabolic pathways such as glucosinolates (GSLs) by defense phytohormones in response to different stresses and nutrient deficiency has been intensively investigated, while how growth‐promoting hormone balances plant secondary and primary metabolism has been largely unexplored. Here, we found that growth‐promoting hormone brassinosteroid (BR) inhibits GSLs accumulation while enhancing biosynthesis of primary sulfur metabolites, including cysteine (Cys) and glutathione (GSH) both in Arabidopsis and Brassica crops, fine‐tuning secondary and primary sulfur metabolism to promote plant growth. Furthermore, we demonstrate that of BRASSINAZOLE RESISTANT 1 (BZR1), the central component of BR signaling, exerts distinct transcriptional inhibition regulation on indolic and aliphatic GSL via direct MYB51 dependent repression of indolic GSL biosynthesis, while exerting partial MYB29 dependent repression of aliphatic GSL biosynthesis. Additionally, BZR1 directly activates the transcription of APR1 and APR2 which encodes rate‐limiting enzyme adenosine 5′‐phosphosulfate reductases in the primary sulfur metabolic pathway. In summary, our findings indicate that BR inhibits the biosynthesis of GSLs to prioritize sulfur usage for primary metabolites under normal growth conditions. These findings expand our understanding of BR promoting plant growth from a metabolism perspective. [ABSTRACT FROM AUTHOR]

The Brassicaceae family is unique in not fostering functional symbiosis with arbuscular mycorrhiza (AM). The family is also special in possessing glucosinolates, a class of secondary metabolites predominantly functioning for plant defence. We have reviewed what effect the glucosinolates of this non‐symbiotic host have on AM or vice versa. Isothiocyanates, the toxic degradation product of the glucosinolates, particularly the indolic and benzenic glucosinolates, are known to be involved in the inhibition of AM. Interestingly, AM colonization enhances glucosinolate production in two AM‐host in the Brassicales family‐ Moringa oleifera and Tropaeolum spp. PHOSPHATE STARVATION RESPONSE 1 (PHR1), a central transcription factor that controls phosphate starvation response also activates the glucosinolate biosynthesis in AM non‐host Arabidopsis thaliana. Recently, the advances in whole‐genome sequencing, enabling extensive ecological microbiome studies have helped unravel the Brassicaceae microbiome, identifying new mutualists that compensate for the loss of AM symbiosis, and reporting cues for some influence of glucosinolates on the microbiome structure. We advocate that glucosinolate is an important candidate in determining the mycorrhizal status of Brassicaceae and has played a major role in its symbiosis‐defence trade‐off. We also identify key open questions in this area that remain to be addressed in the future. [ABSTRACT FROM AUTHOR]

Insect herbivores simultaneously experience bottom‐up effects of plant defensive chemistry and the top‐down effects of natural enemies. At the intersection of these effects are herbivore immune systems, herbivore traits that have largely been overlooked in studies of plant‐insect interactions. Most previous studies have demonstrated compromised immunity of herbivores that feed on plants with higher defensive chemistry. Many studies have used embedded microfilaments or silica beads as proxies for parasitoid eggs. Yet, parasitoids may evade or suppress host immune responses by injecting venom and calyx fluid, or through modifications of their egg surface structure, necessitating studies that include all three trophic levels to obtain a complete picture of how plant traits may modulate herbivore immunity.Here, we examined the effect of host plant species that differ in glucosinolate (anti‐herbivore compounds produced by plants in the Brassicaceae) concentrations on the immune status of an herbivore and its consequences for two species of parasitoids with different life history traits.We found that larvae of the butterfly Pieris rapae that fed on field mustard Brassica rapa, which contain 52‐fold higher glucosinolate concentrations than collards B. oleracea, attained lower body weights and experienced prolonged development to adulthood.Yet, caterpillars that fed on B. rapa had enhanced cellular immunity, as measured by total and differential haemocyte counts as well as melanization capacity, compared to larvae that fed on B. oleracea.In turn, the likelihood that at least some eggs in clutches of the gregarious endoparasitoid Cotesia glomerata would be encapsulated, leading to a reduction in brood size, were three times greater when their host caterpillars fed on B. rapa compared to B. oleracea.Interestingly, eggs of the solitary endoparasitoid Cotesia rubecula were rarely encapsulated irrespective of the host plant on which their host caterpillar fed. Therefore, our results suggest that plant defence metabolites can influence the expression of herbivore immunity, but the effectiveness of this response strongly depends on the identity of the parasitoid and its ability to evade the caterpillar immune response, and possibly the evolution of these trophic interactions in non‐native systems. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Chemical signal‐mediated biological communication is common within bacteria and between bacteria and their hosts. Many plant‐associated bacteria respond to unknown plant compounds to regulate bacterial gene expression. However, the nature of the plant compounds that mediate such interkingdom communication and the underlying mechanisms remain poorly characterized. Xanthomonas campestris pv. campestris (Xcc) causes black rot disease on brassica vegetables. Xcc contains an orphan LuxR regulator (XccR) which senses a plant signal that was validated to be glucose by HPLC‐MS. The glucose concentration increases in apoplast fluid after Xcc infection, which is caused by the enhanced activity of plant sugar transporters translocating sugar and cell‐wall invertases releasing glucose from sucrose. XccR recruits glucose, but not fructose, sucrose, glucose 6‐phosphate, and UDP‐glucose, to activate pip expression. Deletion of the bacterial glucose transporter gene sglT impaired pathogen virulence and pip expression. Structural prediction showed that the N‐terminal domain of XccR forms an alternative pocket neighbouring the AHL‐binding pocket for glucose docking. Substitution of three residues affecting structural stability abolished the ability of XccR to bind to the luxXc box in the pip promoter. Several other XccR homologues from plant‐associated bacteria can also form stable complexes with glucose, indicating that glucose may function as a common signal molecule for pathogen–plant interactions. The conservation of a glucose/XccR/pip‐like system in plant‐associated bacteria suggests that some phytopathogens have evolved the ability to utilize host compounds as virulence signals, indicating that LuxRs mediate an interkingdom signalling circuit. [ABSTRACT FROM AUTHOR]

The rhizosphere microbiome influences many aspects of plant fitness, including production of secondary compounds and defence against insect herbivores. Plants also modulate the composition of the microbial community in the rhizosphere via secretion of root exudates. We tested both the effect of the rhizosphere microbiome on plant traits, and host plant effects on rhizosphere microbes using recombinant inbred lines (RILs) of Brassica rapa that differ in production of glucosinolates (GLS), secondary metabolites that contribute to defence against insect herbivores. First, we investigated the effect of genetic variation in GLS production on the composition of the rhizosphere microbiome. Using a Bayesian Dirichlet‐multinomial regression model (DMBVS), we identified both negative and positive associations between bacteria from six genera and the concentration of five GLS compounds produced in plant roots. Additionally, we tested the effects of microbial inoculation (an intact vs. disrupted soil microbiome) on GLS production and insect damage in these RILs. We found a significant microbial treatment × genotype interaction, in which total GLS was higher in the intact relative to the disrupted microbiome treatment in some RILs. However, despite differences in GLS production between microbial treatments, we observed no difference in insect damage between treatments. Together, these results provide evidence for a full feedback cycle of plant–microbe interactions mediated by GLS; that is, GLS compounds produced by the host plant "feed‐down" to influence rhizosphere microbial community and rhizosphere microbes "feed‐up" to influence GLS production. [ABSTRACT FROM AUTHOR]

Summary: Camelina sativa is an oil crop with low input costs and resistance to abiotic and biotic stresses. The presence of glucosinolates, plant metabolites with adverse health effects, restricts the use of camelina for human and animal nutrition. Cas9 endonuclease‐based targeted mutagenesis of the three homeologs of each of the glucosinolate transporters CsGTR1 and CsGTR2 caused a strong decrease in glucosinolate amounts, highlighting the power of this approach for inactivating multiple genes in a hexaploid crop. Mutagenesis of the three homeologs of each of the transcription factors CsMYB28 and CsMYB29 resulted in the complete loss of glucosinolates, representing the first glucosinolate‐free Brassicaceae crop. The oil and protein contents and the fatty acid composition of the csgtr1csgtr2 and csmyb28csmyb29 mutant seeds were not affected. The decrease and elimination of glucosinolates improves the quality of the oil and press cake of camelina, which thus complies with international standards regulating glucosinolate levels for human consumption and animal feeding. [ABSTRACT FROM AUTHOR]

Premise: Capparis spinosa is a widespread charismatic plant, in which the nocturnal floral habit contrasts with the high visitation by diurnal bees and the pronounced scarcity of hawkmoths. To resolve this discrepancy and elucidate floral evolution of C. spinosa, we analyzed the intrafloral patterns of visual and olfactory cues in relation to the known sensory biases of the different visitor guilds (bees, butterflies, and hawkmoths). Methods: We measured the intrafloral variation of scent, reflectance spectra, and colorimetric properties according to three guilds of known visitors of C. spinosa. Additionally, we sampled visitation rates using a motion‐activated camera. Results: Carpenter bees visited the flowers eight times more frequently than nocturnal hawkmoths, at dusk and in the following morning. Yet, the floral headspace of C. spinosa contained a typical sphingophilous scent with high emission rates of certain monoterpenes and amino‐acid derived compounds. Visual cues included a special case of multisensory nectar guide and color patterns conspicuous to the visual systems of both hawkmoths and bees. Conclusions: The intrafloral patterns of sensory stimuli suggest that hawkmoths have exerted strong historical selection on C. spinosa. Our study revealed two interesting paradoxes: (a) the flowers phenotypically biased towards the more inconsistent pollinator; and (b) floral display demands an abundance of resources that seems maladaptive in the habitats of C. spinosa. The transition to a binary pollination system accommodating large bees has not required phenotypic changes, owing to specific eco‐physiological adaptations, unrelated to pollination, which make this plant an unusual case in pollination ecology. [ABSTRACT FROM AUTHOR]

Summary: Mashua (Tropaeolum tuberosum), an Andean crop used in traditional medicine, has become of interest due to its phytochemicals specifically glucosinolates (GLS). Little is known about the impacts of cold storage and drying processing operations on the GLS composition of mashua‐derived products. This work evaluated the changes in GLS content and profile, derived from GLS biotransformation and myrosinase activity content, during controlled postharvest cold storage (12 °C and 80% RH) and after drying (60 °C and 1.8 m s−1). The GLS content reached its maximum value after 10 days of postharvest cold storage. The derivatives detected were 4‐Methoxybenzyl isothiocyanate, 4‐methoxy Benzeneacetonitrile, 4‐Methoxybenzyl alcohol methyl ether, Benzyl isothiocyanate and Benzeneacetaldehyde. The processing of tubers into flour resulted in significant GLS losses of 38%–87% compared with the respective cold storage treatment. Myrosinase activity showed no correlation with the content and type of GLS and low correlation with isothiocyanates and nitriles present. Our results revealed that drying conditions must be controlled to maintain GLS concentration in the final product. [ABSTRACT FROM AUTHOR]

Strigolactones regulate shoot branching and many aspects of plant growth, development, and allelopathy. Strigolactones are often discussed alongside auxin because they work together to inhibit shoot branching. However, the roles and mechanisms of strigolactones and how they act independently of auxin are still elusive. Additionally, there is still much in general to be discovered about the network of molecular regulators and their interactions in response to strigolactones. Here, we conducted an experiment in Arabidopsis with physiological treatments and strigolactone mutants to determine transcriptional pathways associated with strigolactones. The three physiological treatments included shoot tip removal with and without auxin treatment and treatment of intact plants with the auxin transport inhibitor, N‐1‐naphthylphthalamic acid (NPA). We identified the glucosinolate biosynthesis pathway as being upregulated across strigolactone mutants indicating strigolactone–glucosinolate crosstalk. Additionally, strigolactone application cannot restore the highly branched phenotype observed in glucosinolate biosynthesis mutants, placing glucosinolate biosynthesis downstream of strigolactone biosynthesis. Oxidative stress genes were enriched across the experiment suggesting that this process is mediated through multiple hormones. Here, we also provide evidence supporting non‐auxin‐mediated, negative feedback on strigolactone biosynthesis. Increases in strigolactone biosynthesis gene expression seen in strigolactone mutants could not be fully restored by auxin. By contrast, auxin could fully restore auxin‐responsive gene expression increases, but not sugar signaling‐related gene expression. Our data also point to alternative roles of the strigolactone biosynthesis genes and potential new signaling functions of strigolactone precursors. In this study, we identify a strigolactone‐specific regulation of glucosinolate biosynthesis genes indicating that the two are linked and may work together in regulating stress and shoot branching responses in Arabidopsis. Additionally, we provide evidence for non‐auxin‐mediated feedback on strigolactone biosynthesis and discuss this in the context of sugar signaling. [ABSTRACT FROM AUTHOR]

Summary: Low light intensities affect the outbreak of plant diseases. However, the underlying molecular mechanisms remain poorly understood.High‐performance liquid chromatography analysis of tomato (Solanum lycopersicum) revealed that apoplastic glucose (Glc) levels decreased in response to low light. Conversely, low‐light‐induced susceptibility to Pseudomonas syringae pv tomato (Pst) DC3000 was significantly alleviated by exogenous Glc treatment. Using cell‐based biolayer interferometry assays, we found that Glc specifically binds to the tomato regulator of G protein signaling 1 (RGS1). Laser scanning confocal microscopy imaging revealed that Glc triggers RGS1 endocytosis, which influences the uncoupling of the RGS1‐Gα (GPA1) and GPA1‐Gβ (SlGB1) proteins, in a dose‑ and duration‐dependent manner.Analysis of G protein single and double mutants revealed that RGS1 negatively regulates disease resistance under low light and is required for Glc‐enhanced defense. Downstream of RGS1‐Glc binding, GPA1 negatively mediates the light‐intensity‐regulated defense, whereas SlGB1 positively regulates this process.These results reveal a novel light‐intensity‐responsive defense system that is mediated by a Glc–RGS1–G protein signaling pathway. This information will be critical for future investigations of how plant cells sense extracellular sugars and adjust defense under different environments, as well as for genetic engineering approaches to improve stress resilience. [ABSTRACT FROM AUTHOR]

Summary: Plants face attackers aboveground and belowground. Insect root herbivores can lead to severe crop losses, yet the underlying transcriptomic responses have rarely been studied.We studied the dynamics of the transcriptomic response of Brussels sprouts (Brassica oleracea var. gemmifera) primary roots to feeding damage by cabbage root fly larvae (Delia radicum), alone or in combination with aboveground herbivory by cabbage aphids (Brevicoryne brassicae) or diamondback moth caterpillars (Plutella xylostella). This was supplemented with analyses of phytohormones and the main classes of secondary metabolites; aromatic, indole and aliphatic glucosinolates.Root herbivory leads to major transcriptomic rearrangement that is modulated by aboveground feeding caterpillars, but not aphids, through priming soon after root feeding starts. The root herbivore downregulates aliphatic glucosinolates. Knocking out aliphatic glucosinolate biosynthesis with CRISPR‐Cas9 results in enhanced performance of the specialist root herbivore, indicating that the herbivore downregulates an effective defence.This study advances our understanding of how plants cope with root herbivory and highlights several novel aspects of insect–plant interactions for future research. Further, our findings may help breeders develop a sustainable solution to a devastating root pest. [ABSTRACT FROM AUTHOR]

SUMMARY: Glutathione (GSH) functions as a major sulfur repository and hence occupies an important position in primary sulfur metabolism. GSH degradation results in sulfur reallocation and is believed to be carried out mainly by γ‐glutamyl cyclotransferases (GGCT2;1, GGCT2;2, and GGCT2;3), which, however, do not fully explain the rapid GSH turnover. Here, we discovered that γ‐glutamyl peptidase 1 (GGP1) contributes to GSH degradation through a yeast complementation assay. Recombinant proteins of GGP1, as well as GGP3, showed high degradation activity of GSH, but not of oxidized glutathione (GSSG), in vitro. Notably, the GGP1 transcripts were highly abundant in rosette leaves, in agreement with the ggp1 mutants constantly accumulating more GSH regardless of nutritional conditions. Given the lower energy requirements of the GGP‐ than the GGCT‐mediated pathway, the GGP‐mediated pathway could be a more efficient route for GSH degradation than the GGCT‐mediated pathway. Therefore, we propose a model wherein cytosolic GSH is degraded chiefly by GGP1 and likely also by GGP3. Another noteworthy fact is that GGPs are known to process GSH conjugates in glucosinolate and camalexin synthesis; indeed, we confirmed that the ggp1 mutant contained higher levels of O‐acetyl‐l‐Ser, a signaling molecule for sulfur starvation, and lower levels of glucosinolates and their degradation products. The predicted structure of GGP1 further provided a rationale for this hypothesis. In conclusion, we suggest that GGP1 and possibly GGP3 play vital roles in both primary and secondary sulfur metabolism. Significance Statement: Glutathione (GSH) is a major repository for organic sulfur in plants. In this study, we identified novel GSH degradation enzymes, γ‐glutamyl peptidases (GGPs), which may supply a substantial amount of cysteine in the cell. Moreover, GGPs also function in glucosinolate and camalexin synthesis, so GGPs can be regarded as enzymes that play important roles in both GSH degradation and glucosinolate and camalexin synthesis, that is, primary and secondary sulfur metabolism. [ABSTRACT FROM AUTHOR]

Premise: Invasive plant species often escape from specialist herbivores and are more likely to be attacked by generalist herbivores in the exotic range. Consequently, the shifting defense hypothesis predicts that invasive plants will produce higher concentrations of qualitative defense compounds to deter dominant generalist herbivores in the exotic range. Here, I additionally propose a reduced chemical diversity hypothesis (RCDH), which predicts that reduced herbivory pressure will select for invasive plant genotypes that produce lower diversities of chemical defense compounds in the exotic range. Methods: I tested whether (1) invasive Brassica nigra populations express a lower diversity and an overall higher concentration of glucosinolate compounds than native‐range B. nigra; (2) Brassica nigra individuals that express high diversities and concentrations of glucosinolate compounds are more attractive to specialist and deterrent to generalist herbivores; and (3) tissues of invasive B. nigra are less palatable than tissues of native‐range B. nigra to the generalist herbivores Theba pisana and Helix aspersa. Results: Invasive B. nigra populations produced a significantly lower diversity of glucosinolate compounds, a marginally higher concentration of total glucosinolates, and a significantly higher concentration of sinigrin (the dominant glucosinolate). Leaf tissues of invasive B. nigra were significantly less palatable to T. pisana and marginally less so to H. aspersa. Brassica nigra individuals that expressed high concentrations of total glucosinolate compounds were visited by a low diversity of generalist herbivore species in the field. Conclusions: In line with the RCDH, the lower diversity of glucosinolate compounds produced by invasive B. nigra populations likely resulted from selection imposed by reduced herbivory pressure in the exotic range. [ABSTRACT FROM AUTHOR]

Summary: We show here that the side chain of pogostone, one of the major components of patchouli oil obtained from Pogostemon cablin and possessing a variety of pharmacological activities, is derived from 4‐methylvaleric acid.We also show that 4‐methylvaleric acid is produced through the one‐carbon α‐ketoacid elongation pathway with the involvement of the key enzyme 2‐isobutylmalate synthase (IBMS), a newly identified enzyme related to isopropylmalate synthase (IPMS) of leucine (Leu) biosynthesis.Site‐directed mutagenesis identified Met132 in the N‐terminal catalytic region as affecting the substrate specificity of PcIBMS1. Even though PcIBMS1 possesses the C‐terminal domain that in IPMS serves to mediate Leu inhibition, it is insensitive to Leu.The observation of the evolution of IBMS from IPMS, as well as previously reported examples of IPMS‐related genes involved in making glucosinolates in Brassicaceae, acylsugars in Solanaceae, and flavour compounds in apple, indicate that IPMS genes represent an important pool for the independent evolution of genes for specialised metabolism. [ABSTRACT FROM AUTHOR]

BACKGROUND: Soil fertility is a major concern during vegetable production. Conventional versus organic fertilization has been studied in order to conserve soil properties. While some reports point out an increase in food nutritional properties, the loss of crop yield under organic conditions continues to be a problem. Thus, an experiment with broccoli in the field was carried out, comparing crop management under conventional fertilization (CF) and two soil amendment treatments: manure pellet (M) and an enriched‐biochar (EB) supplemented by an organic fertilizer (AND) applied alone (M + CF; EB+AND) or in combination (M + EB + AND). Crop yield and the nutritional properties in the flowering heads (mineral content, phenolic compounds and glucosinolates (GSLs)), were determined. RESULTS: Enriched‐biochar and manure as a standalone amendment resulted in higher crop yield regarding CF, but not when they were applied in combination. The number of flowering heads with no‐commercial characteristics was lower after enriched‐biochar soil application. Finally, enriched‐biochar treatment enhanced NO3−, PO43− and SO42− levels in the flowering heads, and some of the ion contents can be associated with mineral changes in the soil after the biochar amendment. Also, the contents of phenolic compounds and indole GSLs were higher after enriched‐biochar application compared with the other treatments, GSL increase being due to the higher percentage of sulfur in the plant rather that an adequate N/S ratio. CONCLUSION: Application of enriched‐biochar amendment in the cultivation of broccoli is appropriate, since there are no losses of yield and an increase in nutritional compounds in the flowering heads. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A central role of the endoplasmic reticulum (ER) is the synthesis, folding and quality control of secretory proteins. Secretory proteins usually exit the ER to enter the Golgi apparatus in coat protein complex II (COPII)‐coated vesicles before transport to different subcellular destinations. However, in plants there are specialized ER‐derived vesicles (ERDVs) that carry specific proteins but, unlike COPII vesicles, can exist as independent organelles or travel to the vacuole in a Golgi‐independent manner. These specialized ERDVs include protein bodies and precursor‐accumulating vesicles that accumulate storage proteins in the endosperm during seed development. Specialized ERDVs also include precursor protease vesicles that accumulate amino acid sequence KDEL‐tailed cysteine proteases and ER bodies in Brassicales plants that accumulate myrosinases that hydrolyzes glucosinolates. These functionally specialized ERDVs act not only as storage organelles but also as platforms for signal‐triggered processing, activation and deployment of specific proteins with important roles in plant growth, development and adaptive responses. Some specialized ERDVs have also been exploited to increase production of recombinant proteins and metabolites. Here we discuss our current understanding of the functional diversity, evolutionary mechanisms and biotechnological application of specialized ERDVs, which are associated with some of the highly remarkable characteristics important to plants. [ABSTRACT FROM AUTHOR]

Isothiocyanates are biotoxic degradation products formed as a result of enzymatic hydrolysis of glucosinolates present in Brassica species. The application of biofumigant Brassica crops, as an alternative crop protection method for soilborne pathogens and pests is increasingly gaining interest. However, little is known of the potential of biofumigation to reduce the inoculum of Fusarium species affecting cereals. The aim of this study was to evaluate the antifungal activity of five isothiocyanates, namely allyl, benzyl, ethyl, 2‐phenylethyl and methyl isothiocyanates, against germination and growth of Fusarium graminearum under in vitro conditions. Aromatic isothiocyanates were more inhibitory than the aliphatic isothiocyanates against mycelial growth, whereas the reverse was observed for conidial germination. Among the tested isothiocyanates, allyl and methyl isothiocyanates were more efficient overall, showing lower ED50 values (35–150 mg/L) for conidial germination and mycelial radial growth. The findings suggest that Brassica plants containing allyl and methyl glucosinolates could have a suppressive effect, reducing the inoculum of F. graminearum in soil prior to cereal production. [ABSTRACT FROM AUTHOR]

Summary: The phenotypic plasticity of flowering plants in response to herbivore damage to vegetative tissues can affect plant interactions with flower‐feeding organisms. Such induced systemic responses are probably regulated by defence‐related phytohormones that signal flowers to alter secondary chemistry that affects resistance to florivores. Current knowledge on the effects of damage to vegetative tissues on plant interactions with florivores and the underlying mechanisms is limited.We compared the preference and performance of two florivores on flowering Brassica nigra plants damaged by one of three herbivores feeding from roots or leaves. To investigate the underlying mechanisms, we quantified expression patterns of marker genes for defence‐related phytohormonal pathways, and concentrations of phytohormones and glucosinolates in buds and flowers.Florivores displayed contrasting preferences for plants damaged by herbivores feeding on roots and leaves. Chewing florivores performed better on plants damaged by folivores, but worse on plants damaged by the root herbivore. Chewing root and foliar herbivory led to specific induced changes in the phytohormone profile of buds and flowers. This resulted in increased glucosinolate concentrations for leaf‐damaged plants, and decreased glucosinolate concentrations for root‐damaged plants.The outcome of herbivore–herbivore interactions spanning from vegetative tissues to floral tissues is unique for the inducing root/leaf herbivore and receiving florivore combination. [ABSTRACT FROM AUTHOR]

Cover illustration refers to the article published in this issue (Mann et al., pp. 2182-2195). B Front cover image: b We report CRISPR/Cas9 editing of 10 glucosinolate transporter genes to develop ideal oilseed mustard with the desired low levels of seed glucosinolates while maintaining high glucosinolate levels in other plant organs for uncompromised plant defense. [Extracted from the article]

Summary: Allopolyploid Brassica juncea crops in Brassicaceae are becoming increasingly revitalized as vegetables and oilseeds owing to wide adaptability and significant economic values. However, the genomic differentiation of diversified vegetables and oilseed B. juncea and the genetic basis underlying glucosinolates accumulation have yet to be elucidated. To address this knowledge gap, we report the sequencing of pairwise genomes of vegetable and oilseed B. juncea at chromosome scale. Comparative genomics analysis unveils panoramic structural variation footprints, particularly the genetic loci of HSP20 and TGA1 associated with abiotic and biotic stresses responses between oilseed and vegetable subgroups. We anchored two major loci of MYB28 (HAG1) orthologues caused by copy number variations on A02 and A09 chromosomes using scored genomic SNPs‐based GWAS that are responsible for seed oil quality‐determining glucosinolates biosynthesis. These findings will provide valuable repertories of polyploidy genomic information enabling polyploidy genome evolution studies and precise genomic selections for crucial traits like functional components of glucosinolates in B. juncea crops and beyond. [ABSTRACT FROM AUTHOR]

BACKGROUND Canola meal has limited utilization in feed and food applications because of the presence of antinutritional factors and a high fiber content. Thus, the present study used 3‐day canola seed sprouting followed by hull removal to improve the nutritional quality of canola as a feed and food ingredient to further enhance and diversify the canola market. RESULTS: Seed sprouting and the hull removal process resulted in 63.2% sprouts, 29.3% mix fractions (MF) (hulls, ungerminated seed, and delayed sprouts) and 8.1% mass loss during sprouting. Fresh sprouts and MF were dried, ground and defatted to compare the obtained meals and oils with their counterparts of raw seed. Defatted sprouts (DFSP) resulted in a 46.2% reduction in crude fiber, a 34.3% reduction in acid detergent fiber and a 43.4% reduction in neutral detergent fiber compared to defatted raw seed (DFSE). DFSP provided a 10.1% higher protein content and a 5.9% increase in total amino acid content with higher essential amino acids compared to DFSE. Total carbohydrate was lowered by 5.5%, phytic acid content was lowered by 25.9%, and ash content was lowered by 5.5% in DFSP, whereas total glucosinolate content was higher in DFSP (13.1 μmol g−1) than in DFSE (8.8 μmol g−1). Sprouts and MF showed an oil content of 38.4% and 9.6%, respectively, compared to raw seed (34.5%). CONCLUSION: Sprouting and hull removal of canola seed can potentially provide nutritive meal for food and feed applications. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND Broccoli, kale, and cauliflower contain phenolic compounds and glucosinolates, which have several biological effects on the body. However, because they are thermolabile, many of these substances are lost in the cooking process. Electrospinning encapsulation, using zein as a preservative wall material, can expand the applications of the compounds in the food and pharmaceutical industries. The objective of this research was to characterize broccoli, kale, and cauliflower extracts and encapsulate them with the electrospinning technique using zein. RESULTS: Broccoli, kale, and cauliflower extracts contain five phenolic compounds and three glucosinolates. Fibers from broccoli, kale, and cauliflower showed high encapsulation efficiency, good thermal stability, and nanometric size, especially those containing extract and zein in proportions of up to 35:65. CONCLUSION: Fibers from broccoli, kale, and cauliflower containing extract and zein in proportions of up to 35:65 have the potential for effective nutraceutical application for the control of non‐communicable chronic diseases or application in food packaging. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Cerebral ischaemia-reperfusion (CIR) injury occurs in stroke patients after the restoration of cerebral perfusion. Sinigrin, a phytochemical found in cruciferous vegetables, exhibits strong antioxidant activity. This study investigated the role of sinigrin in oxidative stress using a CIR injury model. The effects of sinigrin were studied in middle cerebral artery occlusion (MCAO) rats and oxygen-glucose deprivation/reoxygenation (OGD/R)-injured SH-SY5Y cells. Sinigrin treatment improved brain injury and neurological deficits induced by MCAO surgery in rats. Sinigrin inhibited apoptosis in brain tissues and SH-SY5Y cells following OGD/R induction. Additionally, sinigrin elevated the levels of superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GSH-Px) while reducing malondialdehyde (MDA) levels. Furthermore, sinigrin inhibited the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signalling pathway. The anti-apoptotic and antioxidant activities of sinigrin in OGD/R-injured SH-SY5Y cells were reversed by TLR4 overexpression. In conclusion, sinigrin inhibits oxidative stress in CIR injury by suppressing the TLR4/MyD88 signalling pathway., (© 2024 John Wiley & Sons Ltd.)

Heterotrimeric G‐proteins are one of the highly conserved signal transducers across phyla. Despite the obvious importance of G‐proteins in controlling various plant growth and environmental responses, there is no information describing the regulatory complexity of G‐protein networks during pathogen response in a polyploid crop. Here, we investigated the role of extra‐large G‐proteins (XLGs) in the oilseed crop Brassica juncea, which has inherent susceptibility to the necrotrophic fungal pathogen Sclerotiniasclerotiorum. The allotetraploid B. juncea genome contains multiple homologs of three XLG genes (two BjuXLG1, five BjuXLG2, and three BjuXLG3), sharing a high level of sequence identity, gene structure organization, and phylogenetic relationship with the progenitors' orthologs. Quantitative reverse transcription PCR analysis revealed that BjuXLGs have retained distinct expression patterns across plant developmental stages and on S. sclerotiorum infection. To determine the role of BjuXLG genes in the B. juncea defence response against S. sclerotiorum, RNAi‐based suppression was performed. Disease progression analysis showed more rapid lesion expansion and fungal accumulation in BjuXLG‐RNAi lines compared to the vector control plants, wherein suppression of BjuXLG3 homologs displayed more compromised defence response at the later time point. Knocking down BjuXLGs caused impairment of the host resistance mechanism to S. sclerotiorum, as indicated by reduced expression of defence marker genes PDF1.2 and WRKY33 on pathogen infection. Furthermore, BjuXLG‐RNAi lines showed reduced accumulation of leaf glucosinolates on S. sclerotiorum infection, wherein aliphatic glucosinolates were significantly compromised. Overall, our data suggest that B. junceaXLG genes are important signalling nodes modulating the host defence pathways in response to this necrotrophic pathogen. [ABSTRACT FROM AUTHOR]

Two trials were carried out to study the effects of copper sulphate (CuSO4) on detoxifying glucosinolates (GLS) in rapeseed cake (RSC) and compare the effects of feeding CuSO4‐treated and untreated RSC on nutrient digestion and nitrogen (N) metabolism in steers. In Trial 1, different concentrations of CuSO4 solution (1.6 vs. 3.2 g CuSO4·5H2O L−1), soaking temperatures (25 vs. 60°C) and drying methods (air drying at 60°C vs. freeze drying) were allocated in a 2 × 2 × 2 factorial arrangement in vitro. In Trial 2, six steers and dietary inclusions of untreated RSC (control), CuSO4‐treated RSC and CuSO4‐added RSC were assigned in a replicated 3 × 3 Latin square design. CuSO4 treatment in vitro decreased the contents of GLS and thiocyanate (TC) in RSC (p < 0.001). The total amount of GLS and TC decreased by 62.7–68.5% for all treatments. The animal trial showed that CuSO4‐treated RSC inclusion decreased ruminal concentration of valerate (p < 0.01), whereas it did not affect ruminal pH, ammonia N and total volatile fatty acids. Compared with the control, feeding CuSO4‐treated or CuSO4‐added RSC had no effect on plasma concentrations of triiodothyronine and thyroxine, N excretion and N retention. CuSO4‐treated RSC tended to increase neutral detergent fibre digestibility (p = 0.072) and urinary excretion of urea (p = 0.056). Urinary excretion of purine derivatives (p = 0.076) and rumen microbial N supply (p = 0.084) tended to decrease when feeding CuSO4‐treated RSC versus control. TC was found to be the only metabolite of GLS in rumen fluid, plasma and urine. It was feasible to detoxify GLS in RSC using low CuSO4 at room temperature. However, feeding CuSO4‐treated or CuSO4‐added RSC had minor effects on rumen fermentation, nutrient digestion and N metabolism in steers. CuSO4 treatment on RSC for feeding steers seems to be unnecessary. [ABSTRACT FROM AUTHOR]

GTR1 and GTR2 transporters are components of the source to sink translocation network of glucosinolates, which are major defence metabolites in the Brassicaceae. These transporters can be genetically manipulated for reduction of seed‐glucosinolates without inhibiting glucosinolate biosynthesis, thereby maintaining the inherent defence potential of plants. However, the different roles of GTRs in influencing tissue‐specific distribution of glucosinolates in agriculturally important Brassica crops are yet unknown. Here, we report functional characterization of two groups of glucosinolate transporters (GTR1 and GTR2) from Brassica juncea based on gene expression data, biochemical analysis, gene‐complementation studies in GTR‐deficient mutants and RNAi‐based knockdown followed by insect feeding experiments. Although both GTRs showed ubiquitous expression patterns and broad substrate specificity, the single‐gene knockdown lines displayed different phenotypes. The GTR2‐knockdown plants showed a significant reduction of glucosinolates in seeds and a higher accumulation in leaves and pods, while the GTR1‐knockdown plants displayed a smaller reduction of glucosinolates in seeds and significantly lower glucosinolate levels in leaves. Consequently, knockdown of GTR2 resulted in higher resistance towards the generalist pest, Spodoptera litura. Overall, our study highlights the distinctive roles of B. juncea GTRs in tissue‐specific accumulation of glucosinolates and the potential for manipulating GTR2 for enhanced nutrition and plant defence. The glucosinolate transporters GTR1 and GTR2 exhibit differential potential for tissue‐specific manipulation of glucosinolate content for enhanced nutrition and defence traits in the oilseed, Brassica juncea. [ABSTRACT FROM AUTHOR]

Summary: Plants are systemically relevant to our planet not only by constituting a major part of its biomass, but also because they produce a vast diversity of bioactive phytochemicals. These compounds often modulate interactions between plants and the environment, and can have substantial effects on plant consumers and their health. By taking a food web perspective, we highlight the role of bioactive phytochemicals in linking soils, plants, animals and humans and discuss their contributions to systems health. The analysis of connections among food web components revealed an underexplored potential of phytochemicals to optimize food web health and productivity. [ABSTRACT FROM AUTHOR]

SUMMARY: Plant metabolism is modulated by a complex interplay between internal signals and external cues. A major goal of all quantitative metabolomic studies is to clone the underlying genes to understand the mechanistic basis of this variation. Using fine‐scale genetic mapping, in this work we report the identification and initial characterization of NAD‐DEPENDENT MALIC ENZYME 1 (NAD‐ME1) as the candidate gene underlying the pleiotropic network Met.II.15 quantitative trait locus controlling variation in plant metabolism and circadian clock outputs in the Bay × Sha Arabidopsis population. Transcript abundance and promoter analysis in NAD‐ME1Bay‐0 and NAD‐ME1Sha alleles confirmed allele‐specific expression that appears to be due a polymorphism disrupting a putative circadian cis‐element binding site. Analysis of transfer DNA insertion lines and heterogeneous inbred families showed that transcript variation of the NAD‐ME1 gene led to temporal shifts of tricarboxylic acid cycle intermediates, glucosinolate (GSL) accumulation, and altered regulation of several GSL biosynthesis pathway genes. Untargeted metabolomic analyses revealed complex regulatory networks of NAD‐ME1 dependent upon the daytime. The mutant led to shifts in plant primary metabolites, cell wall components, isoprenoids, fatty acids, and plant immunity phytochemicals, among others. Our findings suggest that NAD‐ME1 may act as a key gene to coordinate plant primary and secondary metabolism in a time‐dependent manner. Significance Statement: Fine mapping identifies NAD‐ME1 as a candidate underlying a major locus controlling variation in plant metabolism and circadian clock outputs in the Bay × Sha Arabidopsis population. The mutant led to shifts in plant primary metabolites, cell wall components, isoprenoids, fatty acids, and plant immunity phytochemicals, among others. Our findings suggest that NAD‐ME1 may act as a key gene to coordinate plant primary and secondary metabolism in a time‐dependent manner. [ABSTRACT FROM AUTHOR]