Brassica Plants Research Articles

Phytoremediating a Wastewater-Irrigated Soil Contaminated with Toxic Metals: Comparing the Efficacies of Different Crops

A formidable challenge in suburban agriculture is the sustainability of soil health following the use of wastewater for irrigation. The wastewater irrigation likely toxifies the crop plants making them unconsumable. We used a multivariate, completely randomized design in a greenhouse, comparing the phytoextraction capacities of Brassica juncea, Eruca sativa, Brassica rapa, and Brassica napus—all grown on silt loam soil irrigated with industrial wastewater, canal water, and a 1:1 mixture, during 2018. The studied Brassica plants were generally closely efficient in remediating toxic metals found in wastewater irrigated soil. Substantial differences between Brassica and Eruca plants/parts were recorded. For example, B. napus had significantly higher metal extraction or accumulation compared to E. sativa for Zn (71%), Cu (69%), Fe (78%), Mn (79%), Cd (101%), Cr (57%), Ni (92%). and Pb (49%). While the water and plant were the main predictors of metal extraction or accumulation, an interaction between the main effects substantially contributed to Cu, Mn, and Fe extractions from soil and accumulations in plants. Significant correlations between biological accumulation coefficient and biological transfer coefficient for many metals further supported the metal extraction or accumulation efficiencies as: B. napus > B. juncea > B. rapa > E. sativa. Root-stem mobility index correlation with stem-leaf mobility index indicated the metal translocation along the root-stem-leaf continuum. Therefore, we suggest that these crops may not be used for human or animal consumption when grown with industrial wastewater of toxic metal concentrations ≥ permissible limits. Rather these plants may serve as effective remediators of toxic metal-polluted soil.

Integrative analysis based on transcriptome revealed the relation of auxin to turnip hypocotyl-tuber formation

Turnip (Brassica campestris L. ssp. rapifera Matag syn. B. rapa L.) is characterized by bulbous hypocotyl-tuber, which is an important agronomic trait of the Brassica plants, but the molecular mechanism underlying the development of turnip hypocotyl-tuber has rarely been explored. Contrary to turnip, pak-choi (B. campestris L. ssp. chinensis Makino syn. B. rapa ssp. chinensis) is characterized by small and long hypocotyl. Based on the difference in morphological and anatomical characteristics of hypocotyl between turnip and pak-choi at different developmental stages, integrative analysis was performed in this study. Comparative transcriptomic analysis demonstrated that the changes of expression patterns of genes related to plant hormones especially auxin in hypocotyl were closely related to turnip hypocotyl enlargement at the early stages (8 and 32 days after sowing). The immunolocalization of auxin during early hypocotyl development stages also showed auxin signal differences in secondary xylem of hypocotyl between the two subspecies, and further 1-Naphthaleneacetic acid (NAA) treatments confirmed the effect of auxin in turnip hypocotyl-tuber formation. Our study provided valuable information for further exploration of the role of auxin underlying turnip hypocotyl enlargement, enabling a more comprehensive understanding of plant storage organ development.

A new source of bacterial myrosinase isolated from endophytic Bacillus sp. NGB-B10, and its relevance in biological control activity

Plant metabolism interacts strongly with the plant microbiome. Glucosinolates, secondary metabolites synthesized by Brassica plants, are hydrolyzed by myrosinase into bioactive compounds of great importance in human health and plant protection. Compared with myrosinase from plant sources, myrosinase enzymes of microbial origin have not been extensively investigated. Therefore, seven endophytic strains corresponding to Bacillus sp. were isolated from Eruca vesicaria ssp. sativa plants that could hydrolyse glucosinolates (sinigrin) in the culture medium and showed myrosinase activity (0.08–19.92 U mL−1). The bglA myrosinase-related gene encoding the 6-phospho-β-glucosidase (GH 1) from Bacillus sp. NGB-B10, the most active myrosinase-producing bacterium, was successfully identified. Response surface methodology (RSM) was applied to statistically optimize culture conditions for myrosinase production from Bacillus sp. strain NGB-B10. The Plackett–Burman design indicated that nitrogen concentration, incubation period, and agitation speed were the significant parameters in myrosinase production. The application of the Box–Behnken design of RSM resulted in a 10.03-fold increase in enzyme activity as compared to the non-optimized culture conditions. The myrosinase was partially purified by 40% fractionation followed by SDS-PAGE analysis which yielded two subunits that had a molecular weight of 38.6 and 35.0 KDa. The purified enzyme was stable under a broad range of pH (5.5–10) and temperatures (10–65 °C). The hydrolysis products released by bacterial myrosinase from some glucosinolate extracts had higher and/or equivalent in vitro antagonistic activity against several phytopathogenic fungi compared to the nystatin (a broad-spectrum antifungal agent). This study provides original information about a new source of bacterial myrosinase and affords an optimized method to enhance myrosinase production.

Building comprehensive glucosinolate profiles for brassica varieties

Brassica plants play an important role in common agricultural practices, such as livestock feed or biofumigation, due to the bioactivity of the natural degradation products of glucosinolate metabolites. Therefore, the ability to survey comprehensive glucosinolate profiles for individual brassicas is essential for informing proper species selection for the intended application. Current methods for glucosinolate identification and quantification involve complex or unconventional procedures, and proper reference materials are not readily available. Therefore, researchers with limited resources that require glucosinolate profiles are at an extreme disadvantage. In this work, a simple and accurate HPLC-MS method was developed and validated to build preliminary glucosinolate profiles for three agriculturally relevant forage brassica varieties [turnip (B. rapa L.), canola (B. napus L.), and rapeseed (B. napus L.)]. The average glucosinolate content across three herbage collection dates for canola, rapeseed and turnip were 2.9 ± 0.9 mg g−1, 6.4 ± 1.3 mg g−1, and 14 ± 3.4 mg g−1, respectively. GLS concentrations are reported in milligrams of glucosinolate, calculated as sinigrin equivalents, per gram of dry plant material. This semi-quantitative approach for reporting total GLS content in brassicas is accurate within 15%. Several minor individual glucosinolates were identified that have not been previously reported in canola, rapeseed and turnip species, including glucotropaeolin and 4-hydroxyglucobrassicin (canola), glucoraphanin and glucoberteroin (rapeseed), and glucosinalbin and glucobarbarin (turnip). This non-targeted screen of several forage brassica varieties demonstrates the inherent variation in both the individual glucosinolate content and the total glucosinolate profile among brassicas, and highlights the importance of such glucosinolate characterization in agricultural practices. Additionally, the method developed in this study can be used as a tool for researchers with limited resources to build accurate glucosinolate profiles of brassica plants.

Study of genetic modifications of flower development and methylation status in phytoplasma infected Brassica (Brassica rapa L.).

The plants of B. rapa (syn. B. campestris) are the most important food crop of Pakistan for the production of cooking oil. Brassica plants infected by phytoplasma exhibit floral abnormalities including phyllody, virescence, hypertrophied sepal and aborted reproductive organs and affected flower developmental genes which reduces the yield manifold. The expression level of flower developmental genes in healthy and phytoplasma infected brassica were compared by using semi-quantitative reverse transcription polymerase chain reaction and DNA hybridization. In infected brassica, LEAFY (LFY) gene, controlling the development and maintenance of floral organ, and directly involved in controlling the homeotic gene expression was affected, while APETALA2, regulate the production of sepals and petals, were not altered. Whereas the genes WUSCHEL, APETALA3 and AGAMOUS, were significantly down-regulated, that were responsible for the identity of shoot and central meristem, petals and stamens production, and stamens and carpels development, respectively. The GLUB gene, controlling the production of β-1,3-glucanases enzyme, was highly up-regulated. According to DNA hybridization results, AGAMOUS and APETALA3 were restricted to floral organs territories in healthy and phytoplasma infected brassica, indicating that their expression was tissue-specific. These outcomes indicated that flower abnormalities of phytoplasma infected B. rapa are linked with DNA methylation in the expression of homeotic genes regulating flower development. Azacitidine act as a DNA demethylating reagent. By applying the foliar spray of azacitidine during the flower development, cells of Phytoplasma infected plants exhibits demethylation of DNA when treated with azacitidine chemical that incorporated as analogue of cytosine during the cell division stage. B. rapa showed the up-regulation of gene expression level significantly that restore the normal production of flowers, ultimately increase the oil production throughout the world.

The recombinogenic history of turnip mosaic potyvirus reveals its introduction to Japan in the 19th century.

Characterizing the detailed spatial and temporal dynamics of plant pathogens can provide valuable information for crop protection strategies. However, the epidemiological characteristics and evolutionary trajectories of pathogens can differ markedly from one country to another. The most widespread and important virus of brassica vegetables, turnip mosaic virus (TuMV), causes serious plant diseases in Japan. We collected 317 isolates of TuMV from Raphanus and Brassica plants throughout Japan over nearly five decades. Genomic sequences from these isolates were combined with published sequences. We identified a total of eighty-eight independent recombination events in Japanese TuMV genomes and found eighty-two recombination-type patterns in Japan. We assessed the evolution of TuMV through space and time using whole and partial genome sequences of both nonrecombinants and recombinants. Our results suggest that TuMV was introduced into Japan after the country emerged from its isolationist policy (1639–1854) in the Edo period and then dispersed to other parts of Japan in the 20th century. The results of our analyses reveal the complex structure of the TuMV population in Japan and emphasize the importance of identifying recombination events in the genome. Our study also provides an example of surveying the epidemiology of a virus that is highly recombinogenic.

Pest categorisation of Atalodera andina.

The EFSA Panel on Plant Health performed a pest categorisation of Atalodera andina (Nematoda: Heteroderidae) for the European Union (EU) territory. A. andina belongs to the order Rhabditida, subfamily Ataloderinae. This species has not been reported from the EU. It is not included in the EU Commission Implementing Regulation 2019/2072. It is present in the area of the Lake Titicaca of both Peru and Bolivia and in valleys of the region. There is a report in literature stating that specimens were obtained from Chile and identified as A. andina but details on their geographical origin were not given. The identity of A. andina is well established and methods of its identification are available. Natural hosts include the tuber crops Ullucus tuberosus, Oxalis tuberosa and the Andean potato (Solanum tuberosum subsp. andigenum). Experimental hosts include plants of the genus Brassica (such as B. oleracea, B. napus, B. campestris), sugar beet, tomato and clover. Pathways of entry are host plants for planting including seed tubers, subterranean parts of plants intended for consumption, soil as such or attached to plants for planting, machinery or footwear, soil in packaging (bags). Suitable climates exist in the EU but their extent is uncertain and depends on assumptions made on the occurrence of the pest around Lake Titicaca. In the EU, potato, which is grown on about 1,500,000 ha annually, is expected to be the main host of the nematode. Soil and plants for planting are prohibited from import to the EU from third countries where the pest is known to occur. However, this does not cover hosts of A. andina other than species of Solanaceae. The nematode has been reported to damage Andean potato crops, although this has not been quantified. Following its introduction in the EU, A. andina is expected to cause impacts on potato (S. tuberosum subsp. tuberosum), although there is uncertainty on the magnitude of this impact. Also damage on other hosts cannot be excluded. Therefore, the Panel concludes that A. andina satisfies all the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Biofumigation effects of brassicaceous cover crops on soil health in cucurbit agroecosystems in Hawaii, USA

Brassicaceous cover crops, such as brown mustard (Brassica juncea) and oil radish (Raphanus sativus), are commonly used for biofumigation, a process that utilizes isothiocyanates (ITCs) generated from the hydrolysis of glucosinolates in Brassica plants to suppress soil-borne pathogens, including plant-parasitic nematodes. Given the biocidal nature of ITCs, limited information is available on the non-target effects of biofumigation on free-living nematodes, which are reliable soil health indicators. The objectives of this study were to determine if biofumigation methods effective against plant-parasitic nematodes would have non-target effects on free-living nematodes, and to examine the relationships between biofumigation indicators and nematode communities. Three field trials were conducted to examine whether different biofumigation methods would affect free-living nematodes. Tissue maceration of biofumigant crops, soil tillage, and black plastic mulching were adopted singly or in combination to generate different regimes of biofumigation efficacy. Termination of biofumigant crops by tissue maceration and soil tillage followed by black plastic mulching for one week was most effective in suppressing plant-parasitic nematodes and enhancing bacterial decomposition. However, these effects did not last through the subsequent zucchini (Cucurbita pepo) crop cycle. When comparing changes in soil glucose and sulfate concentrations as indicators of biofumigation efficacy, we found that soil sulfate was a better indicator of biofumigation efficacy than soil glucose, owing to the more stable state of sulfate in soil. Canonical correspondence analysis between soil sulfate as a biofumigation indicator and nematode soil health indicators revealed strong positive correlations of sulfate level with the abundances of bacterivorous and carnivorous nematodes, enrichment index, brown mustard biomass, and soil temperature. However, biofumigation did not affect the nematode community structure. This study demonstrated that biofumigation can suppress plant-parasitic nematodes without compromising soil health.

Infection of Metarhizium anisopliae Ma6 and defense responses of host Phyllotreta striolata adults.

Entomopathogenic fungus as biological control agent plays a crucial role in the integrated management of insect pests. Metarhizium anisopliae Ma6 has been identified as a highly pathogenic strain against Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae), one of the most economically important and dominant insect pests damaging Brassica plants. The infection of M. anisopliae Ma6 on P. striolata was observed under stereomicroscopy and scanning electron microscopy (SEM), and biochemical defense responses of P. striolata adults after infection were investigated. The changes in total amino acids and free fatty acids, and the activities of protective enzymes, including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), in P. striolata adults were measured. In stereomicroscopy and SEM observations, a large number of mycelia were observed on the body surface of P. striolata on the 5th day after treatment by M. anisopliae. Many conidia were germinated and covered the body of P. striolata on the 7th day after treatment. The free fatty acid, total amino acid, CAT, POD, and SOD activities all showed an increased and then decreased trend. These results suggest that entomopathogenic fungal infection triggers the defense response of hosts, which induces changes in nutrients and antioxidant enzymes in P. striolata adults. Our findings provide useful information for understanding the potential for using M. anisopliae Ma6 as a biocontrol agent.

Assessment of insects diversity with the influence of industrial pollutants in agricultural zones of District Sialkot, Pakistan

Abstract. Asghar A, Qadeer O, Mushtaq S, Maalik S, Majeed W, Bano N, Nargis S. 2022. Assessment of insects diversity with the influence of industrial pollutants in agricultural zones of District Sialkot, Pakistan. Biodiversitas 23: 2047-2053. Insects are the most important creatures on earth due to their multifunctional role in the environment by providing different services such as biological indicators, decomposers, pollinators, scavengers, pests, and predators agroecosystem. However, with time due to anthropogenic activities such as environmental pollution, industrial waste, and the use of effluents for agriculture, insect fauna has been facing a dramatic threat to their diversity, particularly in most polluted areas. The present study was designed to find insects diversity variation under polluted environments (heavy metals) in agriculture fields having brassica and Rice crops. Two different sites, the tannery and non-tannery areas were selected to sample insects. The total number of insects found in tannery area fields were 2195 and 3753 from the non-tannery area. The abundance of Melanoplus bivittatus (Say, 1825) was highest in the non-tannery area, and Acrida exaltata (Walker, 1859) was highest in tannery area fields. From the tannery area and non-tannery area, the maximum abundance of 32% and 37% were found for order orthoptera. The cadmium concentration in tannery rice crops was 0.626 ppm, and brassica concentration was 0.315 ppm. The cadmium concentration in non-tannery area samples was 0.115 ppm for rice and 0.101 ppm for brassica plants, while 0.1231 ppm for rice and 0.104 ppm for brassica insects. The lead concentration in tannery areas of rice crops was 0.637 ppm, and brassica concentration was 0.672 ppm. The lead concentration in non-tannery area samples was 0.324 ppm for rice and 0.267 ppm for brassica plants, while 0.214 ppm for rice and 0.266 ppm for brassica insects. The diversity and richness were recorded at 3.11 and 3.525 for rice and 3.124 and 3.913 for brassica fields. The species maximum was seen in the non-tannery area, and less abundance was recorded in the tannery area. It is further suggested that preventive measures should be taken to protect insect diversity from balancing nature's ecological balance.

Identification and functional analysis of cation-efflux transporter 1 from Brassica juncea L.

BackgroundBrassica juncea behaves as a moderate-level accumulator of various heavy metal ions and is frequently used for remediation. To investigate the roles of metal ion transporters in B. juncea, a cation-efflux family gene, BjCET1, was cloned and functionally characterized.ResultsBjCET1 contains 382 amino acid residues, including a signature motif of the cation diffusion facilitator protein family, six classic trans-membrane-spanning structures and a cation-efflux domain. A phylogenetic analysis showed that BjCET1 has a high similarity level with metal tolerance proteins from other Brassica plants, indicating that this protein family is highly conserved in Brassica. BjCET1 expression significantly increased at very early stages during both cadmium and zinc treatments. Green fluorescence detection in transgenic tobacco leaves revealed that BjCET1 is a plasma membrane-localized protein. The heterologous expression of BjCET1 in a yeast mutant increased the heavy-metal tolerance and decreased the cadmium or zinc accumulations in yeast cells, suggesting that BjCET1 is a metal ion transporter. The constitutive expression of BjCET1 rescued the heavy-metal tolerance capability of transgenic tobacco plants.ConclusionsThe data suggest that BjCET1 is a membrane-localized efflux transporter that plays essential roles in heavy metal ion homeostasis and hyper-accumulation.

Plant pathogenic bacterium can rapidly evolve tolerance to an antimicrobial plant allelochemical.

Crop losses to plant pathogens are a growing threat to global food security and more effective control strategies are urgently required. Biofumigation, an agricultural technique where Brassica plant tissues are mulched into soils to release antimicrobial plant allelochemicals called isothiocyanates (ITCs), has been proposed as an environmentally friendly alternative to agrochemicals. Whilst biofumigation has been shown to suppress a range of plant pathogens, its effects on plant pathogenic bacteria remain largely unexplored. Here, we used a laboratory model system to compare the efficacy of different types of ITCs against Ralstonia solanacearum plant bacterial pathogen. Additionally, we evaluated the potential for ITC‐tolerance evolution under high, intermediate, and low transfer frequency ITC exposure treatments. We found that allyl‐ITC was the most efficient compound at suppressing R. solanacearum growth, and its efficacy was not improved when combined with other types of ITCs. Despite consistent pathogen growth suppression, ITC tolerance evolution was observed in the low transfer frequency exposure treatment, leading to cross‐tolerance to ampicillin beta‐lactam antibiotic. Mechanistically, tolerance was linked to insertion sequence movement at four positions in genes that were potentially associated with stress responses (H‐NS histone like protein), cell growth and competitiveness (acyltransferase), iron storage ([2‐Fe‐2S]‐binding protein) and calcium ion sequestration (calcium‐binding protein). Interestingly, pathogen adaptation to the growth media also indirectly selected for increased ITC tolerance through potential adaptations linked with metabolism and antibiotic resistance (dehydrogenase‐like protein) and transmembrane protein movement (Tat pathway signal protein). Together, our results suggest that R. solanacearum can rapidly evolve tolerance to allyl‐ITC plant allelochemical which could constrain the long‐term efficiency of biofumigation biocontrol and potentially shape pathogen evolution with plants.

Phytoremediation of toxic heavy metals by Brassica plants: A biochemical and physiological approach

Contamination of soils and water bodies by toxic heavy metals (HMs) such as cadmium (Cd), chromium (Cr), mercury (Hg), arsenic (As), lead (Pb), and zinc (Zn), is a major environmental concern. Phytoremediation by botanical genus Brassica emerges as an important technique, in which plants are used to decontaminate these areas. Brassica spp. are reported as potential phytoremediators and hyperaccumulators our aim was to elucidate the physiological and biochemical potential use of different species belonging to the genus Brassica to bioremediate and tolerate the harmful effects of these environmental contaminants on their metabolism. Since these species display efficient phytoremediation processes, such as phytovolatilization, phytostabilization, and phytoextraction. These species also have physiological processes that aid the absorption, translocation, and accumulation of toxic HMs into low-activity cell organelles, in addition to an efficient enzymatic and non-enzymatic defense mechanism that attenuates the oxidative damage induced by the overproduction of reactive oxygen species (ROS). In addition to enzymatic and non-enzymatic mechanisms, our review also is an effort to gather the scattered information on other phytoremediation assistive techniques, such as the use of chelating and acidifying agents, selection of tolerant cultivars, and genetic engineering. Although techniques for the management and disposal of biomass obtained after the phytoremediation process are reported, this issue still lacks studies that present a consensus regarding which techniques are safer, more efficient, and economically viable. Phytoremediation of toxic HMs by Brassica species is, a promising technique, however, the need for further studies aimed at agronomic techniques that assist in high plant biomass production, tolerance and, structuring the hyperaccumulation network of these contaminants, so that their applicability and feasibility can be used for larger areas (cropping areas).

A high-quality functional genome assembly of Delia radicum L. (Diptera: Anthomyiidae) annotated from egg to adult.

Belowground herbivores are overseen and underestimated, even though they can cause significant economic losses in agriculture. The cabbage root fly Delia radicum (Anthomyiidae) is a common pest in Brassica species, including agriculturally important crops, such as oilseed rape. The damage is caused by the larvae, which feed specifically on the taproots of Brassica plants until they pupate. The adults are aboveground-living generalists feeding on pollen and nectar. Female flies are attracted by chemical cues in Brassica plants for oviposition. An assembled and annotated genome can elucidate which genetic mechanisms underlie the adaptation of D. radicum to its host plants and their specific chemical defences, in particular isothiocyanates. Therefore, we assembled, annotated and analysed the D. radicum genome using a combination of different next-generation sequencing and bioinformatic approaches. We assembled a chromosome-level D. radicum genome using PacBio and Hi-C Illumina sequence data. Combining Canu and 3D-DNA genome assembler, we constructed a 1.3Gbp genome with an N50 of 242Mbp and 6pseudo-chromosomes. To annotate the assembled D. radicum genome, we combined homology-, transcriptome- and ab initio-prediction approaches. In total, we annotated 13,618genes that were predicted by at least two approaches. We analysed egg, larval, pupal and adult transcriptomes in relation to life-stage specific molecular functions. This high-quality annotated genome of D. radicum is a first step to understanding the genetic mechanisms underlying host plant adaptation. As such, it will be an important resource to find novel and sustainable approaches to reduce crop losses to these pests.

Suitability of select micro-green, ornamental and legume plants for use in green walls: a novel brewery wastewater treatment option

ABSTRACT Green walls are increasingly popular in urban settings with demonstrated beneficial use as vertical gardens, building envelops, and uniquely orientated green space to improve urban biodiversity and air quality. This research evaluated the suitability of green wall plants for the preliminary treatment of wastewater generated by food and beverage makers, quantifying suitability with plant growth metrics. Edible micro-green, ornamental, and legume plants were planted in perlite filled pots and irrigated continuously with untreated brewery wastewater or a control of Hoaglands solution. Plants receiving wastewater had less growth than the control. Stem growth for microgreen and legume plants that were started from seed was 798% and 253% less, respectively, when irrigated with 100% brewery wastewater. The stem growth of established ornamental plants was 26% less when irrigated with the wastewater. Wastewater irrigated plants with the highest rates of growth and survivability included the mustard plant (Brassica juncea), and ornamental plants Epipremnum aureum (Golden Pothos) and Chlorophytum comosum (Spider Plant). Growth metrics for wastewater irrigated legumes were higher for plants inoculated with rhizobia, than plants without the inoculation, which suggests low available nitrogen concentrations, rather than toxicity of the wastewater, limited plant growth. The results suggest that ornamental plants such as Epipremnum aureum and Chlorophytum comosum can be sustained, without the addition of supplemental nutrients, in a green wall utilized to treat brewery wastewater.

Membrane Vesicles for Nanoencapsulated Sulforaphane Increased Their Anti-Inflammatory Role on an In Vitro Human Macrophage Model.

At present, there is a growing interest in finding new non-toxic anti-inflammatory drugs to treat inflammation, which is a key pathology in the development of several diseases with considerable mortality. Sulforaphane (SFN), a bioactive compound derived from Brassica plants, was shown to be promising due to its anti-inflammatory properties and great potential, though its actual clinical use is limited due to its poor stability and bioavailability. In this sense, the use of nanocarriers could solve stability-related problems. In the current study, sulforaphane loaded into membrane vesicles derived from broccoli plants was studied to determine the anti-inflammatory potential in a human-macrophage-like in vitro cell model under both normal and inflammatory conditions. On the one hand, the release of SFN from membrane vesicles was modeled in vitro, and two release phases were stabilized, one faster and the other slower due to the interaction between SFN and membrane proteins, such as aquaporins. Furthermore, the anti-inflammatory action of sulforaphane-loaded membrane vesicles was demonstrated, as a decrease in interleukins crucial for the development of inflammation, such as TNF-α, IL-1β and IL-6, was observed. Furthermore, these results also showed that membrane vesicles by themselves had anti-inflammatory properties, opening the possibility of new lines of research to study these vesicles, not only as carriers but also as active compounds.

Beneficial Microbes and Molecules for Mitigation of Soil Salinity in Brassica Species: A Review

Salt stress results from excessive salt accumulation in the soil can lead to a reduction in plant growth and yield. Due to climate change, in the future climatic pressures, changed precipitation cycles and increased temperature will increase the pressures on agriculture, including increasing severity of salt stress. Brassica species contains oilseed and vegetable crops with great economic importance. Advances in understanding the mechanisms of salt stress in Brassica plants have enabled the development of approaches to better induce plant defense mechanisms at the time of their occurrence through the use of beneficial microorganisms or molecules. Both endophytic and rhizospheric microbes contribute to the mitigation of abiotic stresses in Brassica plants by promoting the growth of their host under stress conditions. In this review we summarized so far reported microorganisms with beneficial effects on Brassica plants and their mode of action. Another approach in mitigating the harmful effect of soil salinity may involve the application of different molecules that are involved in the stress response of Brassica plants. We reviewed and summarized their potential mode of action, methods of application and pointed out further research directions.

Triplication is the main evolutionary driving force of NLP transcription factor family in Chinese cabbage and related species

The NODULE-INCEPTION-like protein (NLP) is a plant-specific transcription factor (TF) family that plays an important role in both signal transduction and nitrate assimilation. However, the NLP gene family in Chinese cabbage (Brassica rapa) has yet to be studied. Here we identified 17, 16, and 32 NLP genes in Chinese cabbage, Brassica oleracea, and Brassica napus, respectively. We found that duplication of those NLP genes almost always originated from genome-wide duplication events. Further analysis (using Arabidopsis as a reference) revealed that the NLP family in Chinese cabbage and B. oleracea was characterized by direct expansion caused by whole-genome duplication. By contrast, indirect expansion characterized B. napus, which arose from hybridization and fusion of the two species. In addition, phylogenetic and homology analyses showed that the Brassica NLP gene family has been highly conserved in evolution. Finally, we also identified optimal codons for four studied species. Altogether, through comparative genome analysis methods, we presented compelling evidence that triplication is the main driving force for the NLP TF family's evolution in Chinese cabbage and related Brassica plants, a process evidently highly conserved. This work will help in better understanding the impact of genome-wide duplication on gene families of plants.

Feeding Brassica vegetables to rats leads to the formation of characteristic DNA adducts (from 1-methoxy-3-indolylmethyl glucosinolate) in many tissues

Juices of Brassica vegetables are mutagenic and form characteristic DNA adducts in bacteria and mammalian cells. In this study, we examined whether such adducts are also formed in vivo in animal models. Rats fed raw broccoli ad libitum in addition to normal laboratory chow for 5 weeks showed one major adduct spot and sometimes an additional minor adduct spot in liver, kidney, lung, blood and the gastrointestinal tract, as determined by 32P-postlabelling/thin-layer chromatography. Adducts with the same chromatographic properties were formed when herring sperm DNA (or dG-3’-phosphate) was incubated with 1-methoxy-3-indolylmethyl glucosinolate (phytochemical present in Brassica plants), in the presence of myrosinase (plant enzyme that hydrolyses glucosinolates to bioactive breakdown products). UPLC–MS/MS analysis corroborated this finding: 1-Methoxy-3-indolylmethyl-substituted purine nucleosides were detected in the hepatic DNA of broccoli-fed animals, but not in control animals. Feeding raw cauliflower led to the formation of the same adducts. When steamed rather than raw broccoli was used, the adduct levels were essentially unchanged in liver and jejunum, but elevated in large intestine. Due to inactivation of myrosinase by the steaming, higher levels of the glucosinolates may have reached the large bowl to be activated by glucosidases from intestinal bacteria. In conclusion, the consumption of common Brassica vegetables can lead to the formation of substantial levels of DNA adducts in animal models. The adducts can be attributed to a specific phytochemical, neoglucobrassicin (1-methoxy-3-indolylmethyl glucosinolate).

Cloning and structural elucidation of a brassinosteroids biosynthetic gene (Atdwarf4) and genetic transformation of Indian mustard (Brassica juncea L.)

Phytohormones play critical roles in plant growth and development. Brassinosteroids (BRs) are essential group of phytohormones required for optimum growth of plants and their deficiency causes distinctive dwarf phenotypes in plants. Homeostasis of BRs in plants is maintained by DWARF4 enzyme that mediates multiple 22α-hydroxylation steps in brassinosteroid biosynthesis. Arabidopsis plants over-expressing DWARF4 show increase in inflorescence, number of branches and siliques; thereby increased number of seeds/plant. This suggests that engineering DWARF4 biosynthesis in Brassica plant can be strategized to enhance yield in mustard. In the present study (i) we cloned dwarf4 gene from Arabidopsis using gene specific PCR strategy, (ii) elucidated the three-dimensional structure of DWARF4 protein at molecular level where it revealed presence of four beta sheets and 20 alpha-helices, and (iii) transformed mustard cultivar Pusa Jaikisan with an objective to develop transgenic mustard with enhanced number of siliques. We obtained several putative transgenics with an average transformation efficiency of 3.3%. Molecular characterization with nptII specific primers confirmed presence of transgene in six putative transgenic plants.