Plant Family Brassicaceae Research Articles

Timing is everything: How plants optimize reproduction in a variable environment

Organisms experience a constantly changing environment and must adjust their development to maximize fitness. These "life histories" are fantastically diverse and have fascinated biologists for decades. Recent work published in Cell reveals the complex genetic mechanisms that drive life-history variation within and among species in the Brassicaceae plant family.

Unveiling the chloroplast genomes of Capsella bursa-pastoris, Descurainia sophia, and Lepidium apetalum (Brassicaceae)

We de novo assembled and analysed the chloroplast genomes of Capsella bursa-pastoris, Descurainia sophia, and Lepidium apetalum of the plant family Brassicaceae. These chloroplast genomes exhibited a quadripartite structure characterised by inverted repeat regions (26,268–26,460 bp) separating large single copy (83,771–83,870 bp) and small single copy (17,570–18,014 bp) regions. Genetic analysis revealed 112 unique genes, comprising 78 protein-coding genes, 30 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes. Notably, phylogenetic analysis of 21 species revealed close relationships between C. bursa-pastoris and C. orientalis, D. sophia and D. erodiifolia, and L. apetalum and L. cordatum, with 100% bootstrap support. In conclusion, the analysis of these genomes will contribute to the growing knowledge of chloroplast genomes in the Brassicaceae family and of the specific genera Capsella, Descurainia, and Lepidium.

Characterization of Selenium Speciation in Se-Enriched Crops: Crop Selection Approach.

Accurately quantifying selenium (Se) speciation and transformation in Se-enriched crops is highly significant for human health. The investigation of Se species in Se-enriched crops involves assessing the enrichment of both organic and inorganic Se species, considering their plant families and edible parts. The staple crops of rice, corn, and wheat showed no or less inorganic Se with the increase of total Se; however, potatoes expressed a proportion of selenate [Se(VI)]. In addition, the organic Se proportions in Se-enriched crops of Cruciferous, Brassicaceae, and Umbelliferae plant families were relatively lower than the proportion of inorganic Se. Concurrently, the edible parts of the Se-enriched gramineous or cereal crops enriched with organic Se and crops with fruit, stem, leaf, and root as edible parts contain the maximum percentage of organic Se with a certain proportion of inorganic Se. This study contributes to a sparse body of literature by meticulously discerning appropriate Se-enriched crop selection through a comprehensive evaluation of Se speciation and its organic and inorganic accumulation potential.

Vegetation Cover Management and Landscape Plant Species Composition Influence the Chrysopidae Community in the Olive Agroecosystem.

Habitat manipulation through the promotion of semi-natural habitats such as cover and patch vegetation is a possible means of offsetting the negative impacts of the agricultural practices. A baseline situation is crucial before any successful habitat manipulation is attempted. We studied the effects that current vegetation cover management practices have on plant composition and the potential attraction that the plant families from the semi-natural habitats could have on the Chrysopidae community, a key pest control agent, in five olive farms in Granada (Spain). Vegetation cover was assessed using a point quadrat methodology in eight transects per farm. In addition, the patch vegetation was characterized with 60 transects using a line intercept methodology. The woody patch vegetation and olive tree canopies were vacuumed using a field aspirator to collect adult Chrysopidae. In the cover vegetation we observed great variability in both the richness and diversity of plant communities caused by the vegetation cover management techniques and the transect position (in the middle of the rows or beneath the tree canopy). The plant families with the greatest plant cover were the Asteraceae and Fabaceae, where Asteraceae was favoured by tillage and Fabaceae by grazing, while in the patch vegetation, the predominant families were the Rosaceae and Fagaceae. Our results indicate that the genus Chrysoperla was mostly correlated with the Plantaginaceae, Brassicaceae and Asteraceae plant families in the cover vegetation, and with the Caryophyllaceae and Rosaceae families in the patch vegetation. The genera Apertochrysa and Pseudomallada were associated with the families Malvaceae and Poaceae in the cover vegetation, and with the families Cupressaceae, Poaceae and Pinaceae in the patch vegetation. Our study shows to the farmers the possibilities of vegetation cover management to select plant families for the cover vegetation.

Silencing of a mannitol transport gene in Phelipanche aegyptiaca by the tobacco rattle virus system reduces the parasite germination on the host root

ABSTRACT Root parasitic weed Phelipanche aegyptiaca is an obligate plant parasite that causes severe damage to host crops. Agriculture crops mainly belong to the Brassicaceae, Leguminosae, Cruciferae, and Solanaceae plant families affected by this parasitic weed, leading to the devastating loss of crop yield and economic growth. This root-specific parasitic plant is not able to complete its life cycle without a suitable host and is dependent on the host plant for nutrient uptake and germination. Therefore, selected parasitic genes of P. aegyptiaca which were known to be upregulated upon interaction with the host were chosen. These genes are essential for parasitism, and reduced activity of these genes could affect host-parasitic interaction and provide resistance to the host against these parasitic weeds. To check and examine the role of these parasitic genes which can affect the development of host resistance, we silenced selected genes in the P. aegyptiaca using the tobacco rattle virus (TRV) based virus-induced gene silencing (VIGS) method. Our results demonstrated that the total number of P. aegyptiaca parasite tubercles attached to the root of the host plant Nicotiana benthamiana was substantially decreased in all the silenced plants. However, silencing of the P. aegyptiaca MNT1 gene which encodes the mannitol transporter showed a significantly reduced number of germinated shoots and tubercles. Thus, our study indicates that the mannitol transport gene of P. aegyptiaca plays a crucial role in parasitic germination, and silencing of the PaMNT1 gene abolishes the germination of parasites on the host roots.

Pollen meta-barcoding reveals different community structures of foraged plants by honeybees (Apis mellifera L.) along space-time gradient in Japan

The availability of pollen in urban-rural landscapes is an essential factor that influences the population dynamics of insect pollinators. The amount and diversity of pollen play a pivotal role in the foraging ecology of pollinators for their growth and health, but investigations on the spatio-temporal patterns of foraged plants remain rare, especially in cities as neo - ecosystems. Here, we explored the temporal foraging habits of a highly pollinator (Apis mellifera L.) in Tokyo, including different landscape classes from rural to urban areas. Mixed-pollen samples in each month and each location (N = 17) were analysed using DNA meta-barcoding to identify plants visited by honeybees. The results showed that the landscape class (rural, suburban and urban areas) explains spatial variations in pollen source-plant composition foraged by honeybees, but not in taxa richness. Furthermore, pollen diversity and pollen source-plant composition showed a strong seasonal dependence. A higher plant richness and foraged woody taxa was found to occur in spring, which was mainly dominated by the genera Prunus and Acer. In summer and autumn, the genera Trifolium and Plantago of the herbaceous stratum were the most visited plants. The Fabaceae, Rosaceae, Brassicaceae, Plantaginaceae, and Onagraceae plant families were the most frequently observed in all combined samples. The present study contributes to a deeper understanding of the foraging ecology of A. mellifera colonies across urban-rural gradient surrounding mega-cities such as Tokyo.

Prospects for Knockout of MYB60, a Transcriptional Repressor of Anthocyanin Biosynthesis, in Brassicaceae Plants by Genome Editing

The Brassicaceae plant family contains many economically important crops such as Brassica napus L., Brassica rapa L., Brassica oleracea L., Brassica juncea L., Eruca sativa Mill., Camelina sativa L. and Raphanus sativus L. Insufficient data on the genetic regulation of agronomic traits in these species complicates the editing of their genomes. In recent years, the attention of the academic community has been drawn to anthocyanin hyperaccumulation. This trait is not only beneficial for human health, but can also increase plant resistance to stress. MYB transcription factors are the main regulators of flavonoid biosynthesis in plants. Some of them are well studied in Arabidopsis thaliana. The AtMYB60 gene is a transcriptional repressor of anthocyanin biosynthesis, and it also negatively impacts plant responses to drought stress. Myb60 is one of the least studied transcription factors with similar functions in Brassicaceae. There is a high degree of homology between predicted MYB60 genes of A. thaliana and related plant species. However, functions of these homologous genes have never been studied. Gene knockout by CRISPR/Cas technology remains the easiest way to perform genome editing in order to discover the role of individual plant genes. Disruption of genes acting as negative regulators of anthocyanin biosynthesis could result in color staining of plant tissues and an increase in stress tolerance. In the present study, we investigated the AtMYB60 gene and its homologs in Brassicaceae plants and suggested universal gRNAs to knockout these genes.
 Keywords: CRISPR, Brassicaceae, MYB60, knockout, anthocyanin

How do trained panelists characterize baby leafy greens? A comparison of descriptive analysis and Napping.

Baby leafy greens are one of the fastest growing segments of the salad green market. Baby leafy greens are generally more mild tasting than their fully-mature counterparts. Nevertheless, a diversity of plant species can be grown as baby greens, which exhibit a wide range of sensory attributes. Sensory profiles of baby leaf varieties have not been well described in the literature. This study aimed to describe the differences between several baby leafy green varieties from the plant family Brassicaceae and those which were non-Brassicaceae, and to compare two descriptive methods, traditional descriptive analysis (DA) and Napping, a rapid profiling technique. Both methods used the same trained panelists. In the first study, the panel (n=11) developed a lexicon for and evaluated four samples grown in a controlled aeroponic environment. In the second study, 12 commercially available samples were evaluated with DA (n=8) and Napping (n=11). Panelists identified differences in the pungency, bitterness, and ''green'' attributes across all samples. Principal component analysis (PCA) was used to model associations between the samples and the sensory attributes. The PCA extracted three factors. PC1 ranged from pungent qualities to sweet/grassy, PC2 included green color, and PC3 included saltiness and sourness. The Napping showed similar sample separation (RV=0.67), but included relevant textural terms (''chewy''; ''rubbery'') not used in the DA. The current lexicon can be applied to a large range of baby leafy greens. Napping showed good correspondence with DA and can be deployed with agricultural products where time and other resources may be limited. PRACTICAL APPLICATION: Sensory evaluation methods have traditionally been applied in the food industry with processed products.While traditional methods such as descriptive analysis have been used to profile products, rapid and inexpensive profiling methods should be screened for their value in describing agricultural products. The results of this study can be applied to breeding and grow-out programs to aid in optimization of the processing,storage, and quality control for the rapidly expanding baby leafy green market.

Homology-Based Interactions between Small RNAs and Their Targets Control Dominance Hierarchy of Male Determinant Alleles of Self-Incompatibility in Arabidopsis lyrata

Self-incompatibility (SI) is conserved among members of the Brassicaceae plant family. This trait is controlled epigenetically by the dominance hierarchy of the male determinant alleles. We previously demonstrated that a single small RNA (sRNA) gene is sufficient to control the linear dominance hierarchy in Brassica rapa and proposed a model in which a homology-based interaction between sRNAs and target sites controls the complicated dominance hierarchy of male SI determinants. In Arabidopsis halleri, male dominance hierarchy is reported to have arisen from multiple networks of sRNA target gains and losses. Despite these findings, it remains unknown whether the molecular mechanism underlying the dominance hierarchy is conserved among Brassicaceae. Here, we identified sRNAs and their target sites that can explain the linear dominance hierarchy of Arabidopsis lyrata, a species closely related to A. halleri. We tested the model that we established in Brassica to explain the linear dominance hierarchy in A. lyrata. Our results suggest that the dominance hierarchy of A. lyrata is also controlled by a homology-based interaction between sRNAs and their targets.

Rosaceae, Brassicaceae and pollen beetles: exploring relationships and evolution in an anthophilous beetle lineage (Nitidulidae, Meligethes-complex of genera) using an integrative approach

BackgroundMeligethes are pollen-beetles associated with flowers of Rosaceae as larvae. This genus currently consists of 63 known species in two subgenera, Meligethes and Odonthogethes, predominantly occurring in the eastern Palaearctic. We analyzed 74 morphological and ecological characters (169 states) of all species, as well as of 11 outgroup species from 7 Meligethinae genera (including Brassicogethes), to investigate their phylogeny. We also conducted a parallel molecular analysis on 9 Meligethes, 9 Odonthogethes, 3 Brassicogethes and 2 Meligethinus species based on DNA sequence data from mitochondrial (COI, 16S) and nuclear (CAD) genes.ResultsMorphological phylogenetic reconstructions supported the monophyly of the whole genus and clades corresponding to purported subgenera Meligethes s.str. and Odonthogethes. Main species-groups were mostly confirmed, however some unresolved polytomies remained. Molecular data placed members of Brassicogethes (including 42 mostly W Palearctic species associated with Brassicaceae) as sister to Odonthogethes, with this clade being sister to Meligethes s.str. This phylogenetic scenario suggests that monophyletic Meligethes s.str., Odonthogethes and Brassicogethes should be regarded alternatively as three subgenera of a monophyletic Meligethes, or three genera in a monophyletic genus-complex, with mutually monophyletic Brassicogethes and Odonthogethes. Molecular analyses estimated the origin of this lineage at ca. 14–15 Mya from a common stem including Meligethinus.ConclusionsWe hypothesize that the ancestor of Meligethes specialized on Rosaceae in the Middle Miocene (likely in Langhian Age) and subsequently radiated during Late Miocene and Plio-Pleistocene maintaining a trophic niche on this plant family. This radiation was primarily due to geographic isolation in E Asiatic mountain systems. Combined evidence from morphology, ancestral state parsimony reconstruction of host-plant associations and molecular evidence suggested that Rosoideae (Rosa spp.) represented the ancestral hosts of Meligethes s.str., followed by an independent shift of ancestral Odonthogethes (ca. 9–15 Mya) on Rubus (Rosoideae) and members of Rosaceae Spiraeoideae. Other ancestral Odonthogethes probably shifted again on the unrelated plant family Brassicaceae (maybe 8–14 Mya in S China), allowing a rapid westward radiation of the Brassicogethes clade.

Comprehensive Evaluation of Metabolites and Minerals in 6 Microgreen Species and the Influence of Maturity.

ABSTRACTBackgroundMicrogreens are the young leafy greens of many vegetables, herbs, grains, and flowers with potential to promote human health and sustainably diversify the global food system. For successful further integration into the global food system and evaluation of their health impacts, it is critical to elucidate and optimize their nutritional quality.ObjectivesWe aimed to comprehensively evaluate the metabolite and mineral contents of 6 microgreen species, and the influence of maturity on their contents.MethodsPlant species evaluated were from the Brassicaceae (arugula, broccoli, and red cabbage), Amaranthaceae (red beet and red amaranth), and Fabaceae (pea) plant families. Nontargeted metabolomics and ionomics analyses were performed to examine the metabolites and minerals, respectively, in each microgreen species and its mature counterpart.ResultsNontargeted metabolomics analysis detected 3321 compounds, 1263 of which were annotated and included nutrients and bioactive compounds. Ionomics analysis detected and quantified 26 minerals including macrominerals, trace minerals, ultratrace minerals, and other metals. Principal component analysis indicated that microgreens have distinct metabolite and mineral profiles compared with one another and with their mature counterparts. Several compounds were higher (P < 0.05; fold change ≥2) in microgreens compared with their mature counterparts, whereas some were not different or lower. In many cases, compounds that were higher in microgreens compared with the mature counterpart were also unique to that microgreen species.ConclusionsThese data provide evidence for the nutritional quality of microgreens, and can inform future research and development aimed at characterizing and optimizing microgreen nutritional quality and health impacts.

Seed and soil transmission of downy mildew (Perofascia lepidii) in seed producing garden cress

Downy mildew on garden cress caused by Perofascia lepidii has become prevalent in organic seed producing areas of Germany resulting in limited seed production and high yield losses. Downy mildew occurrence in young plants in fields that have never been cultivated with garden cress raised questions about infested seeds and soils as sources of the primary inoculum and the role of other members of the plant family Brassicaceae as hosts of P. lepidii. To address these questions 31 seed lots from nine garden cress fields were examined for contamination using P. lepidii species-specific PCR assays. DNA of P. lepidii was detected in 17 seed lots out of 31. In bioassays no disease was observed on plants grown from infested seed lots but in a few plants grown from seeds. The significance of soilborne inoculum was investigated by assessing disease incidence in plants grown in soil samples. Garden cress with downy mildew symptoms were recorded when plants were grown in pathogen infested soil samples. The results show that P. lepidii is able to survive in the soil and can be a primary inoculum source for downy mildew disease. Oospores formed in infected plants underpin the role of these survival structures that get incorporated into soil after harvesting. In a host specificity-test none of the tested species Brassica juncea; Brassica napus; Brassica rapa subsp. pekinensis; Brassica rapa silvestris; Raphanus sativus var. oleiformis; Raphanus sativus var. sativus; Sinapis alba; Sinapis nigra; Arabidopsis thaliana; Capsella bursa-pastoris; Cardamine pratense; Cardaria draba; Nasturtium officinale were infected by P. lepidii.

Evolutionary and biochemical analyses reveal conservation of the Brassicaceae telomerase ribonucleoprotein complex.

The telomerase ribonucleoprotein complex (RNP) is essential for genome stability and performs this role through the addition of repetitive DNA to the ends of chromosomes. The telomerase enzyme is composed of a reverse transcriptase (TERT), which utilizes a template domain in an RNA subunit (TER) to reiteratively add telomeric DNA at the ends of chromosomes. Multiple TERs have been identified in the model plant Arabidopsis thaliana. Here we combine a phylogenetic and biochemical approach to understand how the telomerase RNP has evolved in Brassicaceae, the family that includes A. thaliana. Because of the complex phylogenetic pattern of template domain loss and alteration at the previously characterized A. thaliana TER loci, TER1 and TER2, across the plant family Brassicaceae, we bred double mutants from plants with a template deletion at AtTER1 and T-DNA insertion at AtTER2. These double mutants exhibited no telomere length deficiency, a definitive indication that neither of these loci encode a functional telomerase RNA. Moreover, we determined that the telomerase components TERT, Dyskerin, and the KU heterodimer are under strong purifying selection, consistent with the idea that the TER with which they interact is also conserved. To test this hypothesis further, we analyzed the substrate specificity of telomerase from species across Brassicaceae and determined that telomerase from close relatives bind and extend substrates in a similar manner, supporting the idea that TERs in different species are highly similar to one another and are likely encoded from an orthologous locus. Lastly, TERT proteins from across Brassicaceae were able to complement loss of function tert mutants in vivo, indicating TERTs from other species have the ability to recognize the native TER of A. thaliana. Finally, we immunoprecipitated the telomerase complex and identified associated RNAs via RNA-seq. Using our evolutionary data we constrained our analyses to conserved RNAs within Brassicaceae that contained a template domain. These analyses revealed a highly expressed locus whose disruption by a T-DNA resulted in a telomeric phenotype similar to the loss of other telomerase core proteins, indicating that the RNA has an important function in telomere maintenance.

Root filtering, rather than host identity or age, determines the composition of root-associated fungi and oomycetes in three naturally co-occurring Brassicaceae

The plant family Brassicaceae includes some of the most studied hosts of plant microbiomes, improving our knowledge of microbial diversity, community assembly rules, and effects on host performance. Compared to bacteria, eukaryotes in the microbiome of Brassicaceae remain understudied, especially under field conditions. Here, we assessed the impact of host identity and age on the assembly of fungal and oomycete root communities, using DNA metabarcoding of roots and associated soil of three annual co-habiting Brassicaceae collected at two growth stages from a site untouched for a long time. Our results showed that communities of root-associated fungi are more diverse and structured across factors than those of oomycetes. In both cases, plant identity and growth stage had little influence on the community structure of fungi and oomycetes, whereas soil/root compartment had a strong effect by filtering, resulting in a reduction of the number of microorganisms in roots as compared to the surrounding soil. The enrichment in roots with respect to soil of specific fungi and oomycetes, such as members of the Helotiales or the Peronosporales, suggests a specialization towards the asymptomatic colonization of plant tissues that could be relevant to host fitness and health.

Overcoming Glucosinolate-Myrosinase-Isothiocyanate Defense System by Plant Pathogenic Fungi

Natural compounds play an important role in shaping living plant responses. The resistance of plants is dependent on the formation and production of antimicrobial compounds of secondary metabolites. Glucosinolates (GSLs) are the main source of phytoanticipin in Brassicaceae and other plant families. The biological activity of glucosinolates are dependent on the release of various toxic compounds due to hydrolysis by myrosinase, isothiocyanate (ITC) is glucosinolate-breakdown products that inhibit the growth of microorganisms. In this review, we aim to understand how fungal pathogens overcome the glucosinolate-myrosinase-isothiocyanate system. The pathogens overwhelm the plant's defense system in various ways and disable each component of the system. Many plant pathogens may not cause tissue damage or activation of the glucosinolate-myrosinase-isothiocyanate system, others degrade or transforms the intact GSLs to less or non-toxic products, or inhibit the hydrolysis of GSLs catalyzed by myrosinase, or formed special mechanisms to detoxify toxic GSLs degradation products.

A dietary assessment tool to estimate arsenic and cadmium exposures from locally grown foods

Certain food products have been shown to accumulate arsenic (As) and cadmium (Cd) making it critical to monitor individual's intake, particularly when they live near sources of environmental contamination. After a literature review, a novel dietary assessment was conducted to estimate a child's potential exposure to these metal(loid)s via consumption of locally grown foods in communities impacted by active or legacy resource extraction activities. Mean ingestion rates of As- and Cd-translocating crops belonging to the Asteraceae, Brassicaceae, Caricaceae, Amaranthaceae, Cucurbitaceae, Liliaceae, Solanaceae, Apiaceae, and Fabaceae plant families were calculated for children: 1 to < 2years, 2 to < 3years, and 3 to < 6years of age. These calculated ingestion rates ranged from 0 to 143,571mgday-1. Farmer-consumer relationship was the leading motivation for buying locally grown foods, while lack of experience/unfamiliarity was the most frequently reported reason for not buying locally. The median percentages of child's yearly consumption of fruits and vegetables originating from stores (conventionally grown) and from local sources (farmer's market) were 48% and 38%, respectively. Tomato was the crop with the highest intake rate among children 1 to < 2years and 2 to < 3years of age and broccoli for children 3 to < 6years of age. It was concluded that families who are reliant on locally grown food products may be disproportionately exposed to As and Cd, which could cause detrimental health effects.

Aminorex identified in horse urine following consumption of Barbarea vulgaris; a preliminary report

BackgroundAminorex, (RS)-5- Phenyl-4,5-dihydro-1,3-oxazol-2-amine, is an amphetamine-like anorectic and in the United States a Drug Enforcement Administration [DEA] Schedule 1 controlled substance. Aminorex in horse urine is usually present as a metabolite of Levamisole, an equine anthelmintic and immune stimulant. Recently, Aminorex identifications have been reported in horse urine with no history or evidence of Levamisole administration. Analysis of the urine samples suggested a botanical source, directing attention to the Brassicaceae plant family, with their contained GlucoBarbarin and Barbarin as possible sources of Aminorex. Since horsepersons face up to a 1 year suspension and a $10,000.00 fine for an Aminorex identification, the existence of natural sources of Aminorex precursors in equine feedstuffs is of importance to both individual horsepersons and the industry worldwide.ResultsTesting the hypothesis that Brassicaceae plants could give rise to Aminorex identifications in equine urine we botanically identified and harvested flowering Kentucky Barbarea vulgaris, (“Yellow Rocket”) in May 2018 in Kentucky and administered the plant orally to two horses. Analysis of post-administration urine samples yielded Aminorex, showing that consumption of Kentucky Barbarea vulgaris can give rise to Aminorex identifications in equine urine.ConclusionsAminorex has been identified in post administration urine samples from horses fed freshly harvested flowering Kentucky Barbarea vulgaris, colloquially “Yellow Rocket”. These identifications are consistent with occasional low concentration identifications of Aminorex in equine samples submitted for drug testing. The source of these Aminorex identifications is believed to be the chemically related Barbarin, found as its precursor GlucoBarbarin in Kentucky Barbarea vulgaris and related Brassicaceae plants worldwide.

Efficient and environmentally friendly method for carotenoid extraction from Paracoccus carotinifaciens utilizing naturally occurring Z-isomerization-accelerating catalysts

Abstract This study aimed to improve the efficiency of Paracoccus carotinifaciens-derived carotenoid (astaxanthin, adonirubin, adonixanthin) extraction using environmentally friendly Z-isomerization-accelerating catalysts. Adding naturally occurring catalysts such as isothiocyanates and polysulfides to the extraction solvent significantly improved the efficiency of carotenoid extraction, likely because of enhanced solubility of carotenoid Z-isomers compared with all-E-isomers. Indeed, addition of the catalysts markedly increased the content of carotenoid Z-isomers in the resulting extract. The use of a catalyst allyl isothiocyanate, which is abundantly included in Brassicaceae plant family, at high extraction temperature and long extraction time led to increased carotenoid recovery and Z-isomer content. These findings will enhance the efficiency of organic solvent-based extraction of carotenoids from carotenoid-rich sources. Numerous studies have reported that the Z-isomers of carotenoids exhibit greater bioavailability and antioxidant capacity than the all-E-isomers. Hence, the method proposed here utilizing Z-isomerization-accelerating catalysts could enhance both the extraction efficiency and beneficial health effects of carotenoids.

Chemical Aspects of Biological Activity of Isothiocyanates and Indoles, the Products of Glucosinolate Decomposition.

There is growing evidence that cancer chemoprevention employing natural, bioactive compounds may halt or at least slow down the different stages of carcinogenesis. A particularly advantageous effect is attributed to derivatives of sulfur-organic phytochemicals, such as glucosinolates (GLs) synthesized mainly in Brassicaceae plant family. GLs are hydrolysed enzymatically to bioactive isothiocyanates (ITC) and indoles, which exhibit strong anti-inflammatory and anti-carcinogenic activity. Highly bioavailable electrophilic ITC are of particular interest, as they can react with nucleophilic groups of important biomolecules to form dithiocarbamates, thiocarbamates and thioureas. These modifications seem responsible for the chemopreventive activity, but also for genotoxicity and mutagenicity. It was documented that ITC can permanently bind to important biomolecules such as glutathione, cytoskeleton proteins, transcription factors NF-κB and Nrf2, thiol-disulfide oxidoreductases, proteasome proteins or heat shock proteins. Furthermore, ITC may also affect epigenetic regulation of gene expression, e.g. by inhibition of histone deacetylases. Some other derivatives of glucosinolates, especially indoles, are able to form covalent bonds with nucleobases in DNA, which may result in genotoxicity and mutagenicity. This article summarizes the current state of knowledge about glucosinolates and their degradation products in terms of possible interactions with reactive groups of cellular molecules.

Adaptation of flea beetles to Brassicaceae: host plant associations and geographic distribution of Psylliodes Latreille and Phyllotreta Chevrolat (Coleoptera, Chrysomelidae).

The cosmopolitan flea beetle genera Phyllotreta and Psylliodes (Galerucinae, Alticini) are mainly associated with host plants in the family Brassicaceae and include economically important pests of crucifer crops. In this review, the host plant associations and geographical distributions of known species in these genera are summarised from the literature, and their proposed phylogenetic relationships to other Alticini analysed from published molecular phylogenetic studies of Galerucinae. Almost all Phyllotreta species are specialised on Brassicaceae and related plant families in the order Brassicales, whereas Psylliodes species are associated with host plants in approximately 24 different plant families, and 50% are specialised to feed on Brassicaceae. The current knowledge on how Phyllotreta and Psylliodes are adapted to the characteristic chemical defence in Brassicaceae is reviewed. Based on our findings we postulate that Phyllotreta and Psylliodes colonised Brassicaceae independently from each other.