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Capsella bursa-pastoris (L.) Medik, shepherd’s purse, is a cosmopolitan summer or winter annual weed species distributed throughout temperate and subtropical regions of the world and is considered one of the most common plants on earth. It is an opportunistic annual that colonizes newly disturbed, open or dry environments and is ubiquitous in cultivated lands in Canada. In annual crops in western Canada, C. bursa-pastoris has been among the 20 most abundant weeds since the first weed surveys in 1970. It is most easily distinguished by its small white four-petalled flowers and its heart-shaped seed-pods, but exhibits considerable variation in leaf shape and flowering time. It has been used for food and medicine by numerous cultures. Its golden-brown seeds are produced in large numbers predominantly through self-pollination and can form a substantial seed bank, with reported values ranging to several hundred thousand seeds m−2. While seeds usually disperse near the mother plant, long-distance dispersal by attaching to vehicles, people and other vectors may be facilitated by its mucilaginous coat. Capsella bursa-pastoris does not produce fertile hybrids with other species of economic or ecological significance. It is generally well controlled by soil-applied and foliar (post-emergence) herbicides although its presence in agricultural fields may result in substantial yield loss, as documented in cole crops in North America and grain crops in Europe. The species can host a wide range of insect, nematode, fungal, viral, and bacterial pests that may damage crop species.

Cruciferous weeds have been shown to harbor diverse Xanthomonas campestris pathovars, including the agronomically damaging black rot of cabbage pathogen, X. campestris pv. campestris. However, the importance of weeds as inoculum sources for X. campestris pv. campestris outbreaks in New York remains unknown. To determine if cruciferous weeds act as primary reservoirs for X. campestris pv. campestris, fields that were rotating between cabbage or had severe black rot outbreaks were chosen for evaluation. Over a consecutive 3-year period, 148 cruciferous and noncruciferous weed samples were collected at 34 unique sites located across five New York counties. Of the 148 weed samples analyzed, 48 X. campestris isolates were identified, with a subset characterized using multilocus sequence analysis. All X. campestris isolates originated from weeds belonging to the Brassicaceae family, with predominant weed hosts being shepherd’s purse (Capsella bursa-pastoris), wild mustard (Sinapis arvensis), yellow rocket (Barbarea vulgaris), and pennycress (Thlaspi arvense). Identifying pathogenic X. campestris weed isolates was rare, with only eight isolates causing brown necrotic leaf spots or typical V-shaped lesions on cabbage. There was no evidence of cabbage-infecting weed isolates persisting in an infected field by overwintering in weed hosts; however, similar cabbage and weed X. campestris haplotypes were identified in the same field during an active black rot outbreak. X. campestris weed isolates are genetically diverse both within and between fields, but our findings indicate that X. campestris weed isolates do not appear to act as primary sources of inoculum for B. oleracea fields in New York.

The shift from outcrossing to selfing is one of the main evolutionary transitions in plants. It is accompanied by profound effects on reproductive traits, the so-called selfing syndrome. Because the transition to selfing also implies deep genomic and ecological changes, one also expects to observe a genomic selfing syndrome. We took advantage of the three independent transitions from outcrossing to selfing in the Capsella genus to characterize the overall impact of mating system change on RNA expression, in flowers but also in leaves and roots. We quantified the extent of both selfing and genomic syndromes, and tested whether changes in expression corresponded to adaptation to selfing or to relaxed selection on traits that were constrained in outcrossers. Mating system change affected gene expression in all three tissues but more so in flowers than in roots and leaves. Gene expression in selfing species tended to converge in flowers but diverged in the two other tissues. Hence, convergent adaptation to selfing dominates in flowers, whereas genetic drift plays a more important role in leaves and roots. The effect of mating system transition is not limited to reproductive tissues and corresponds to both adaptation to selfing and relaxed selection on previously constrained traits. De två sista författarna delar sistaförfattarskapet.

Background and Aims Self-fertilization is often associated with ecological traits corresponding to the ruderal strategy, and selfers are expected to be less competitive than outcrossers, either because of a colonization/competition trade-off or because of the deleterious genetic effects of selfing. Range expansion could reduce further competitive ability while polyploidy could mitigate the effects of selfing. If pollinators are not limited, individual fitness is thus expected to be higher in outcrossers than in selfers and, within selfers, in polyploids than in diploids. Although often proposed in the botanical literature and also suggested by meta-analyses, these predictions have not been directly tested yet. Methods In order to compare fitness and the competitive ability of four Capsella species with a different mating system and ploidy level, we combined two complementary experiments. First, we carried out an experiment outdoors in north-west Greece, i.e. within the range of the obligate outcrossing species, C. grandiflora, where several life history traits were measured under two different disturbance treatments, weeded plots vs. unweeded plots. To better control competition and to remove potential effects of local adaptation of the outcrosser, we also performed a similar competition experiment but under growth chamber conditions. Key Results In the outdoor experiment, disturbance of the environment did not affect the phenotype in any of the four species. For most traits, the obligate outcrossing species performed better than all selfing species. In contrast, polyploids did not survive or reproduce better than diploids. Under controlled conditions, as in the field experiment, the outcrosser had a higher fitness than selfing species and was less affected by competition. Finally, contrary to the outdoor experiment where the two behaved identically, polyploid selfers were less affected by competition than diploid selfes. Conclusions In the Capsella genus, selfing induces lower fitness than outcrossing and can also reduce competitive ability. The effect of polyploidy is, however, unclear. These results highlight the possible roles of ecological context in the evolution of selfing species.

Naturally occurring mutants whose phenotype recapitulates the changes that distinguish closely related species are of special interest from the evolutionary point of view. They can give a key about the genetic control of the changes that led to speciation. In this study, we described lepidium-like (lel), a naturally occurring variety of an allotetraploid species Capsella bursa-pastoris that is characterized by the typical loss of all four petals. In some cases, one or two basal flowers in the raceme had one or two small petals. The number and structure of other floral organs are not affected. Our study of flower development in the mutant showed that once initiated, petals either cease further development and cannot be traced in anthetic flowers or sometimes develop to various degrees. lel plants showed an earlier beginning of floral organ initiation and delayed petal initiation compared to the wild-type plants. lel phenotype has a wide geographical distribution, being found at the northern extremity of the species range as well as in the central part. The genetic analysis of inheritance demonstrated that lel phenotype is controlled by two independent loci. While the flower in the family Cruciferae generally has a very stable structure (i.e., four sepals, four petals, six stamens, and two carpels), several deviations from this ground plan are known, in particular in the genus Lepidium, C. bursa-pastoris is an emerging model for the study of polyploidy (which is also very widespread in Cruciferae); the identification and characterization of the apetalous mutant lays a foundation for further research of morphological evolution in polyploids.

The present study was conducted to investigate the morphology, anatomy, karyotype, palynology, biogeography and seed germination of Capsella bursa – pastoris. Also, the ecological characteristics and metabolic products were examined. C. bursa – pastoris (shepherd’s purse) is annual cruciferous herb shows considerably variety of habit form. It is a serious weed responsible for yield loss of many crops. The stem shows the typical dicot characters, with intervascular cambium gives few secondary tissues and has wide parenchymatous pith. The leaf has adaxial epidermal cells of midrib are large and projecting from the blade. The root shows normal secondary thickening and the ruptured epidermis covered by multilayered periderm. The chromosomes are 2n = 16. Pollen grains are spheroidal isopolar, tricolpate with sinuaperturate. The highest rate of seeds germination attained at 30 - 35o C, low salinity (0 – 0.2 M NaCl) and 25 – 30 mm rainfall. Capsella community comprised 25 species belonging to 15 families. Cynodon dactylon, Urtica urens, Rumex dentatus and Lamium amplexicaule were the common associates. The major life – forms were therophytes, hemicryptophytes and geophytes. The assemblage of this community belongs to six chorotypes with predominance of Mediterranean and Irano – Turanian. Capsella flourished in wet, loose, non – saline soil. The nutritive value was 69.29 cal./ 100g. The residues of the different extracts of leaves, stems and roots were 15.64, 11. 97 and 8.30 %, respectively. The polyphenols and flavonoids were detected in ethyl alcohol, chloroform and acetone extracts. These extracts exhihited antioxidant and antimicrobial spectrum only against. Bacillus cereus, Staphyloccus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa.

The research was aimed to identify fruits morphological characteristics of 33 taxa belonging to the Lepidieae tribe from Brassicaceae. The characteristics of the fruit's general shape, apex shape, dimensions, colors, surface ornamentation, and beak were determined, the results indicated the importance of each of those characters in isolated species, In general, all the tribe's fruits were open capsule and short silicula. According to the dimensions of fruit, three species can be distinguished as a group with dimensions greater than 20mm, as in Brossardia, Coluteocarpus, and Didymophysa, and depending on the shape, it was possible to differentiate the species within this group, while the other species were less than 20 mm. in dimensions. They were distinguished by the general shapes, as the fruits of the Aethionema species were distinguished by their winged shaped, whereas the fruits of the genus Biscutella are bi-lobed, and the fruits have an inverted semi-triangular shape in the Capsella and peltate with prominent veins in the genus Horwoodia, or maybe peltate and longitudinally splintered with dark veins in Iberis, while the genus Sameraria fruit is circular to semi-circular characterized by intermediate appendages, while the individuals of the genus Isatis have linear-oblong fruits, and the species of both genus Lipidium and Hymenolobus were distinguished by their small and elliptic fruits and could be differentiated according to other fruits features. So could be conclude the importance of the characteristic of the general shape of the fruit firstly in species isolation then size, ornamentation, and some other traits.

Despite the importance of dormancy and dormancy cycling for plants’ fitness and life cycle phenology, a comprehensive characterization of the global and cellular epigenetic patterns across space and time in different seed dormancy states is lacking. Using Capsella bursa-pastoris (L.) Medik. (shepherd’s purse) seeds with primary and secondary dormancy, we investigated the dynamics of global genomic DNA methylation and explored the spatio-temporal distribution of 5-methylcytosine (5-mC) and histone H4 acetylated (H4Ac) epigenetic marks. Seeds were imbibed at 30 °C in a light regime to maintain primary dormancy, or in darkness to induce secondary dormancy. An ELISA-based method was used to quantify DNA methylation, in relation to total genomic cytosines. Immunolocalization of 5-mC and H4Ac within whole seeds (i.e., including testa) was assessed with reference to embryo anatomy. Global DNA methylation levels were highest in prolonged (14 days) imbibed primary dormant seeds, with more 5-mC marked nuclei present only in specific parts of the seed (e.g., SAM and cotyledons). In secondary dormant seeds, global methylation levels and 5-mC signal where higher at 3 and 7 days than 1 or 14 days. With respect to acetylation, seeds had fewer H4Ac marked nuclei (e.g., SAM) in deeper dormant states, for both types of dormancy. However, the RAM still showed signal after 14 days of imbibition under dormancy-inducing conditions, suggesting a central role for the radicle/RAM in the response to perceived ambient changes and the adjustment of the seed dormancy state. Thus, we show that seed dormancy involves extensive cellular remodeling of DNA methylation and H4 acetylation.

Shepherd&rsquo, s purse (Capsella bursa-pastoris) is a cosmopolitan annual weed and a promising model plant for studying allopolyploidization in the evolution of angiosperms. Though plant mitochondrial genomes are a valuable source of genetic information, they are hard to assemble. At present, only the complete mitogenome of C. rubella is available out of all species of the genus Capsella. In this work, we have assembled the complete mitogenome of C. bursa-pastoris using high-precision PacBio SMRT third-generation sequencing technology. It is 287,799 bp long and contains 32 protein-coding genes, 3 rRNAs, 25 tRNAs corresponding to 15 amino acids, and 8 open reading frames (ORFs) supported by RNAseq data. Though many repeat regions have been found, none of them is longer than 1 kbp, and the most frequent structural variant originated from these repeats is present in only 4% of the mitogenome copies. The mitochondrial DNA sequence of C. bursa-pastoris differs from C. rubella, but not from C. orientalis, by two long inversions, suggesting that C. orientalis could be its maternal progenitor species. In total, 377 C to U RNA editing sites have been detected. All genes except cox1 and atp8 contain RNA editing sites, and most of them lead to non-synonymous changes of amino acids. Most of the identified RNA editing sites are identical to corresponding RNA editing sites in A. thaliana.

A high-density SNP map was constructed and several novel QTL for branch angle across six environments in Brassica napus were identified. Branch angle is a major determinant for the ideotype of a plant, while the mechanisms underlying this trait in Brassica napus remain elusive. Herein, we developed one doubled haploid population from a cross involving one Capsella bursa-pastoris derived B. napus intertribal introgression line with the compressed branches and wooden stems, and constructed a high-density SNP map covering the genetic distance of 2242.14 cM, with an average marker interval of 0.73 cM. After phenotypic measurements across six environments, the inclusive composite interval mapping algorithm was conducted to analyze the QTL associated with branch angle. In single-environment analysis, a total of 17 QTL were detected and mainly distributed on chromosomes A01, A03, A09 and C03. Of these, three major QTL, qBA.A03-2, qBA.C03-3 and qBA.C03-4 were steadily expressed, each explaining more than 10% of the phenotypic variation in at least two environments. Compared with other results on rapeseed branch angle, these major QTL were newly detected. In QTL by environment interactions (QEI) mapping, 10 QTL were identified, and the QTL average effect and QEI effect were estimated. Of these, 7 QTL were detected in both single-environment analysis and QEI mapping. Based on the physical positions of SNPs and the functional annotation of the Arabidopsis thaliana genome, 27 genes within the QTL regions were selected as candidate genes, including early auxin-responsive genes, small auxin-up RNA, auxin/indoleacetic acid and gretchenhagen-3. These results may pave the way for deciphering the genetic control of branch angle in B. napus.

Cold stress is one of the major limitations to crop productivity worldwide. We investigated the effects of multiple gene expression from cold tolerant Capsella bursa-pastoris in transgenic tobacco (Nicotiana tabaccum) plants. We combined CblCE53 and CbCBF into a reconstruct vector by isocaudomers. Plant overexpression of CbICE53 under the stress inducible CbCOR15b promoter and CbCBF under a constitutive promoter showed increased tolerance to both chilling and freezing temperatures in comparison to wild-type plants, according to the electrolyte leakage and relative water content. The expressions of endogenous cold-responsive genes in transgenic tobacco (NtDREB1, NtDREB3, NtERD10a and NtERD10b) were obviously upregulated under normal and low temperature conditions. These results suggest that the CbICE53 + CbCBF transgenic plants showed a much greater cold tolerance as well as no dwarfism and delayed flowering. Thus they can be considered as a potential candidate for transgenic engineering for cold tolerant tobacco.

Maca (Lepidium meyenii) is an Andean crop of narrow distribution, but because of the nutritional and health value, its cultivation area is rapidly expanding. By a broad-spectrum resistance mechanism against various pathogens, just a few diseases have been reported on maca, among which downy mildew is a potential threat to its cultivation. The occurrence of this disease was, so far, restricted to the native area of maca. However, here we report that it was recently introduced into South Korea. As the causal pathogen has initially been attributed to Hyaloperonospora parasitica (syn. Peronospora parasitica), which was thought to affect various Brassicaceae, but is, in fact, restricted to Capsella bursa-pastoris, the identity of this pathogen remains uncertain. In this study, morphological and phylogenetic data revealed that maca downy mildew is unrelated to any species of Hyaloperonospora and instead belongs to the previously monotypic genus Perofascia. It differs markedly from the type species, Perofascia lepidii, and consequently Perofascia macaicola sp. nov. is described and illustrated here. Considering the quick expansion of cultivated land with maca, quarantine measures for this pathogen might be appropriate for hindering the spread of the disease through the international trade of maca.

The aerial parts of Capsella bursa-pastoris (L.) Medic are used to treat nephritis, edema and enteritis. Every barber knows that C. bursa-pastoris had a good anti-inflammatory effect. This suggests that the extracted components from C. bursa-pastoris could potentially treat inflammatory disease. For discovering of the anti-inflammatory effects and chemical composition of C. bursa-pastoris, EtOAc extract was extracted from C. bursa-pastoris (EECB) and researched on EECB’s anti-inflammatory effects. On the carrageenan-induced paw oedema experiment, the EECB used at the doses (100, 200 and 300 mg/kg) after 10 h (p < 0.01), 5 h (p < 0.01) and 3 h (p < 0.01), respectively, showed significant anti-inflammatory effects. Moreover, on the egg-albumin-induced inflammation experiment, the EECB used at the doses 200 and 300 mg/kg after 4 h (p < 0.01) and 2 h (p < 0.01), respectively, showed significant anti-inflammatory effects. In accordance with the HPLC isolation of the EECB, there are four major compounds, namely, apigenin-7-O-β-D-glucopyranoside (S1), luteolin-7-O-β-D-glucopyranoside (S2), α-adenosine (S3), and uridine (S4), which may explain the activity. Key words: Capsella bursa-pastoris (L.) Medic, anti-inflammatory, high performance liquid chromatography (HPLC) isolation, flavonoids.

Green lacewings (Neuroptera: Chrysopidae) are key biological control agents found in a broad range of crops. Given the importance of enhancing their presence and conservation, in this study, we aim to identify and to determine the relative importance of the pollen consumed by Chrysoperla lucasina (Lacroix, 1936) from 29 pollen types offered by 51 native plant species sown in an experimental farm in Villarrubia in the south of Spain. For the purposes of this study, C. lucasina specimens were captured in the late spring of 2016 and 2017. The pollen types and other components in the alimentary canal of C. lucasina were microscopically identified using the transparency method, which is a novel technique applied to green lacewings captured in the field. The results show that (i) C. lucasina feeds on over half of the pollen types offered by the sown plant species, with no differences in behaviour by sex or year; (ii) Capsella bursa-pastoris was the most frequently identified pollen type in the alimentary canal; (iii) the majority of pollen types identified correspond to sown native plant species and not to surrounding plant species; and that (iv) most of the adults studied also consumed honeydew. Our feeding study has important implications for the selection of plant mixtures for ground cover restoration and flower vegetation strips in Mediterranean agroecosystems, which complements our previous findings on how C. lucasina use native plant species as host and reproduction sites. The plant species Capsella bursa-pastoris and Biscutella auriculata, which are best suited to provide pollen, host and reproduction sites for C. lucasina in late spring, should consequently be included in the proposed plant mixtures for Mediterranean agroecosystems., Junta de Andalucia P12-AGR-1419, Consejo Superior de Investigaciones Cientificas (CSIC) 201840E055

In flowering plants, pollen tubes are attracted to the ovule by secreted peptides to release the sperm cells for double fertilization. This process is species-specific and acts as an important stage of reproductive isolation between species. Here we identified a cysteine-rich peptide TICKET2 in Arabidopsis thaliana and its orthologs in Arabidopsis lyrata and Capsella rebella that can attract the conspecific pollen tubes, but not the pollen tubes of relative species in Brassicaceae. Genetic knockout of the AtTICKET subclade compromised the pollen tube attraction efficiency. This study identified a new pollen tube attracting signal and shed light on the molecular basis of reproductive isolation.

Five herbaceous plant species (Aquilegia vulgaris L., Capsella bursa-pastoris L., Dactylis glomerata L., Taraxacum officinale Wigg., and Trifolium repens L.) were sampled at twelve plots in the radioactively contaminated Chernobyl exclusion zone. These plots comprise dose rates from 0.27 to 12.5 μGy/h. The sensitivity of each plant species to chronic multigenerational radiation exposure was estimated using a broad range of parameters, including transcriptional, biochemical, physiological, morphological, and reproductive end-points. We suggest that chronic radiation exposure may influence the state of antioxidant system of chronically irradiated plants in a species-specific way, possibly leading to changes in photosynthetic capacity. ATP and ABA contents were not influenced by chronic irradiation at the plots. For most of the species studied, chlorophyll a fluorescence measurements may be a more appropriate way to assess the stress response to chronic irradiation, while biochemical parameters had significantly higher natural heterogeneity. High-throughput sequencing of the transcriptome of C. bursa-pastoris leaves from radioactively contaminated plots revealed significant stress response to chronic irradiation and supported a predicted important role of histones and chaperons in adaptation to chronic radiation exposure in field conditions. Overall, the results suggest that a prediction of herbaceous species sensitivity to chronic radiation might be initially derived from data on sensitivity to acute radiation exposure.

The interactions of plants with their pollinators are thought to be a driving force in the evolution of angiosperms. Adaptation to a new pollinator involves coordinated changes in multiple floral traits controlled by multiple genes. Surprisingly, such complex genetic shifts have happened numerous times during evolution. Here we report on the genetic basis of the changes in one such trait, floral scent emission, in the genus Petunia (Solanaceae). The increase in the quantity and complexity of the volatiles during the shift from bee to hawkmoth pollination was due to de novo expression of the genes encoding benzoic acid/salicylic acid carboxyl methyltransferase (BSMT) and benzoyl-CoA:benzylalcohol/2-phenylethanol benzoyltransferase (BPBT) together with moderately increased transcript levels for most enzymes of the phenylpropanoid/benzenoid pathway. Loss of cinnamate-CoA ligase (CNL) function as well as a reduction in the expression of the MYB transcription factor ODO1 explain the loss of scent during the transition from moth to hummingbird pollination. The CNL gene in the hummingbird-adapted species is inactive due to a stop codon, but also appears to have undergone further degradation over time. Therefore, we propose that loss of scent happened relatively early in the transition toward hummingbird pollination, and probably preceded the loss of UV-absorbing flavonols. The discovery that CNL is also involved in the loss of scent during the transition from outcrossing to selfing in Capsella (Brassicaceae) (see the accompanying paper) raises interesting questions about the possible causes of deep evolutionary conservation of the targets of evolutionary change.

The enormous species richness of flowering plants is at least partly due to floral diversification driven by interactions between plants and their animal pollinators [1, 2]. Specific pollinator attraction relies on visual and olfactory floral cues [3-5]; floral scent can not only attract pollinators but also attract or repel herbivorous insects [6-8]. However, despite its central role for plant-animal interactions, the genetic control of floral scent production and its evolutionary modification remain incompletely understood [9-13]. Benzenoids are an important class of floral scent compounds that are generated from phenylalanine via several enzymatic pathways [14-17]. Here we address the genetic basis of the loss of floral scent associated with the transition from outbreeding to selfing in the genus Capsella. While the outbreeding C. grandiflora emits benzaldehyde as a major constituent of its floral scent, this has been lost in the selfing C. rubella. We identify the Capsella CNL1 gene encoding cinnamate: CoA ligase as responsible for this variation. Population genetic analysis indicates that CNL1 has been inactivated twice independently in C. rubella via different novel mutations to its coding sequence. Together with a recent study in Petunia [18], this identifies cinnamate: CoA ligase as an evolutionary hotspot for mutations causing the loss of benzenoid scent compounds in association with a shift in the reproductive strategy of Capsella from pollination by insects to self-fertilization., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 904

Two new flavonoids (1 and 2), named 4′,7-dihydroxy-5-hydroxymethyl-8-prenylflavonoid and 4′,7-dihydroxy-5-hydroxymethyl-6,8-diprenylflavonoid, together with seven known flavonoids (3–9) were isolated from the aerial parts of Capsella bursa-pastoris (L.) Medik., Brassicaceae, for the first time. The chemical structures of the purified compounds (1–9) were identified by their spectroscopic data and references. Moreover, compounds (1–9) were evaluated for their hepatoprotective activities against d-galactosamine induced toxicity in WB-F344 cells by using a MTT colorimetric method. As a result, compounds 2, 3, 6, and 9 (10 μM) exhibited moderate hepatoprotective activities. Keywords: 5-Hydroxymethyl flavonoid, NMR, HR-ESI-MS, Spectral data, In vitro, Hepatoprotective activity

The tribe Camelineae (Brassicaceae) contains eight genera: Arabidopsis, Camelina, Capsella, Catolobus, Chrysochamela, Neslia, Noccidium and Pseudoarabidopsis. Little is known about pollen morphology in these taxa, and this limits research on gene flow, aerobiology, reproductive biology, systematics and palaeobotany. In this study, pollen from 13 taxa representing all of the genera in the tribe Camelineae were examined using light and scanning electron microscopy. Measurements of pollen size in Camelina (mean 26.4 µm) and Arabidopsis (mean 30.4 µm) showed that these genera contain taxa with relatively large pollen that could be classified as medium-sized pollen. The largest pollen were from Camelina microcarpa (mean 37.6 µm) and C. sativa (mean 35.6 µm). Conversely, Pseudoarabidopsis had the smallest pollen (mean 18.4 µm) in the Camelineae. Capsella bursa-pastoris was distinct in the tribe in having tectum discontinuities. Catolobus and Neslia shared a similar pollen shape that tended to be subsphe...

Glucosinolates are unique thioglucosides that evolved in the order Brassicales. These compounds function in plant adaptation to the environment, including combating plant pathogens, herbivore deterrence and abiotic stress tolerance. In line with their defensive functions glucosinolates usually accumulate constitutively in relatively high amounts in all tissues of Brassicaceae plants. Here we performed glucosinolate analysis in different organs of selected species representing Capsella, Camelina and Neslia genera, which similarly as the model plant Arabidopsis thaliana belong to the Camelineae tribe. We also identified orthologs of A. thaliana glucosinolate biosynthetic genes in the published genomes of some of the investigated species. Subsequent gene expression and phylogenetic analyses enabled us an insight into the evolutionary changes in the transcription of these genes and in the sequences of respective proteins that occurred within the Camelineae tribe. Our results indicated that glucosinolates are highly abundant in siliques and roots of the investigated species but hardly, if at all, produced in leaves. In addition to this unusual tissular distribution we revealed reduced structural diversity of methionine-derived aliphatic glucosinolates (AGs) with elevated accumulation of rare long chain AGs. This preference seems to correlate with evolutionary changes in genes encoding methylthioalkylmalate synthases that are responsible for the elongation of AG side chains. Finally, our results indicate that the biosynthetic pathway for tryptophan-derived indolic glucosinolates likely lost its main functions in immunity and resistance towards sucking insects and is on its evolutionary route to be shut off in the investigated species.

Shepherd's purse (Capsella bursa-pastoris (L.) Medicus) is an edible and wild medicinal plant widely distributed in China. This plant has been cultivated in Shanghai, China, since the end of the 19th century. Infection of C. bursa-pastoris by Plasmodiophora brassicae, the causal agent of clubroot disease on Brassica spp. has been reported in Korea (2), but is not known to occur in China. In February of 2011, stunted and wilted shepherd's purse (SP) plants were observed in a field planted to oilseed rapes (B. napus) in Sichuan Province of China. Symptomatic SP plants also exhibited root galls. Disease incidence was 6.2% and 100% for SP and B. napus, respectively. Root galls on diseased SP plants were collected for pathogen identification. Many resting spores were observed when the root galls were examined under a light microscope. The resting spores were circular in shape, measuring 2.0 to 3.1 μm in diameter (average 2.6 μm). PCR amplification was conducted to confirm the pathogen. DNA was extracted from root galls and healthy roots (control) of SP. Two primers, TC2F (5′-AAACAACGAGTCAGCTTGAATGCTAGTGTG-3′) and TC2R (5′-CTTTAGTTGTGTTTCGGCTAGGATGGTTCG-3′) were used to detect P. brassicae (1). No PCR amplifications were observed with the control DNA as template. A fragment of the expected size (approximately 520 bp) was obtained when DNA was amplified from diseased roots of SP. These results suggest that the pathogen in the galled roots of SP is P. brassicae. Pathogenicity of P. brassicae in SP was tested on plants of both SP and Chinese cabbage (CC) (B. campestris ssp. pekinensis). A resting spore suspension prepared from naturally infected SP roots was mixed with a sterilized soil in two plastic pots, resulting in a final concentration of 5 × 106 spores/g soil. Soil treated with the same volume of sterile water was used as a control. Seeds of SP and CC were pre-germinated on moist filter paper for 2 days (20°C) and seeded into the infested and control pots, one seed per pot for planted for CC and four seeds per pot for SP. The pots were placed in a chamber at 15 to 25°C under 12 h light and 12 h dark. Plants in each pot were uprooted after 4 weeks and the roots of each plant were washed under tap water and rated for clubroot disease. No disease symptoms were observed in the control treatments of SP or CC. Plants of both species showed symptoms of clubroot, with the disease incidence of 62.5% and 100% on SP and CC, respectively. The pathogen was isolated from diseased roots of each plant and confirmed as P. brassicae based on morphological characteristics and PCR detection. To our knowledge, this is the first report of clubroot disease on C. bursa-pastoris in Sichuan Province of China. This finding suggests that it may be necessary to manage C. bursa-pastoris in cruciferous vegetable (cabbage, turnip) and oilseed rape production fields. References: (1) T. Cao et al. Plant Dis. 91:80, 2007. (2) W. G. Kim et al. Microbiology 39:233, 2011.

The movement of genes between crops and closely-related weeds has the potential to create economic and environmental problems. Camelina sativa (L.) Crantz is a promising oilseed crop and minor weed in North America, but ecological risk assessment is needed to predict crop-weed gene flow. In this study, reciprocal crosses between C. sativa cultivars and 17 Brassicaceae species in the genera Arabidopsis, Arabis, Barbarea, Camelina, Cardamine, Erysimum, and Lepidium were performed. F1 hybrids were formed between C. sativa cultivars and three species: Camelina alyssum (Mill.) Thell., Camelina microcarpa Andrz. Ex DC., and Capsella bursa-pastoris (L.) Medik. None of the other Brassica species formed hybrid offspring. F1 hybrids from C. sativa × C. alyssum showed the same pollen viability and fecundity as the parents, while hybrids from C. sativa × C. microcarpa had reduced pollen viability, silicle (pod) number and seed production. Intergeneric F1 hybrids from Camelina sativa × Capsella bursa-pastoris were sterile and this correlated with large decreases in pollen viability and number of ovules/flower. In addition, the SSR markers could be applied to identify progenies in C. sativa breeding programs as well as auxiliarily assess possibility of gene flow between C. sativa and weedy relatives. Principle coordinate analysis (PCoA) made from SSR markers clearly divided into 12 species into five groups of species. Especially, C. sativa was classified into one group with those two interfertile C. microcarpa, and C. alyssum but distinctly separated from Camelina hispida var. grandiflora (Boiss.) Hedge, Camelina laxa C. A. Mey and Camelina rumelica Velen. This division among the Camelina species was consistent with their capacity to produce fertile F1 hybrids with C. sativa. The hybridization results suggest that gene flow is likely between cultivated C. sativa and the North American weeds C. alyssum and C. microcarpa.

Fruits exhibit a vast array of different 3D shapes, from simple spheres and cylinders to more complex curved forms; however, the mechanism by which growth is oriented and coordinated to generate this diversity of forms is unclear. Here, we compare the growth patterns and orientations for two very different fruit shapes in the Brassicaceae: the heart-shaped Capsella rubella silicle and the near-cylindrical Arabidopsis thaliana silique. We show, through a combination of clonal and morphological analyses, that the different shapes involve different patterns of anisotropic growth during three phases. These experimental data can be accounted for by a tissue level model in which specified growth rates vary in space and time and are oriented by a proximodistal polarity field. The resulting tissue conflicts lead to deformation of the tissue as it grows. The model allows us to identify tissue-specific and temporally specific activities required to obtain the individual shapes. One such activity may be provided by the valve-identity gene FRUITFULL, which we show through comparative mutant analysis to modulate fruit shape during post-fertilisation growth of both species. Simple modulations of the model presented here can also broadly account for the variety of shapes in other Brassicaceae species, thus providing a simplified framework for fruit development and shape diversity., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 986

Treatment of plants with exogenous salicylic acid (SA) improves resistance to many bacterial pathogens, but can suppress resistance to insect herbivores. While plants vary naturally in constitutive SA, whether such differences are predictive of resistance to insect herbivores has not been studied previously. We examined the possible role of this endogenous SA in structuring the interactions between the cabbage white butterfly, Pieris rapae, and ten hosts in the mustard family (Brassicaceae). Because P. rapae has multiple generations that utilize different hosts across the year, we included five spring-flowering mustards and five summer-flowering mustards that co-occur in ruderal habitats in upstate New York. Under common garden conditions, the spring flowering mustards (Capsella bursa-pastoris, Draba verna, Cardamine impatiens, Barbarea vulgaris, and Arabidopsis thaliana) were significantly more resistant to P. rapae, supporting 42 % less herbivory (P = 0.015) and 64 % lower relative growth rates (P = 0.007), relative to the summer flowering mustards (Sisymbrium altissimum, Brassica nigra, Sinapis arvense, Lepidium campestre, and Arabis canadensis). Leaf total constitutive SA explained significant variation in larval herbivory (R2 = 75.3 %, P = 0.007) and relative growth rates (R2 = 59.4 %, P = 0.043). The three species with the lowest levels of constitutive SA (Capsella bursa-pastoris, Draba verna, and Cardamine impatiens) were the most resistant to larvae. Barbarea vulgaris and Arabis canadensis were notable exceptions, exhibiting high SA concentrations and intermediate resistance to P. rapae. These results suggest a curvilinear relationship between leaf constitutive SA and the herbivory by P. rapae, and they provide some insight into the ecology and possible management of this economically important crop pest. Electronic supplementary material The online version of this article (doi:10.1007/s10886-015-0572-z) contains supplementary material, which is available to authorized users.

The development of transgenic oilseed Camelina sativa (2n = 40) and the potential for hybridization with its weedy relative Capsella bursa-pastoris (2n = 36) necessitates a careful evaluation of the reproductive compatibility between the species. Here, we conducted over 1800 crosses (emasculation and manual pollination) to examine the ability of 10 Canadian C. bursa-pastoris (♀) accessions to hybridize with five accessions of C. sativa (♂). Seven hybrids were confirmed among 586 putative hybrids screened with species-specific markers, indicating a hybridization rate of 1.5 hybrids per 10 000 ovules pollinated. All seven hybrids had intermediate DNA content compared to their parents, were morphologically distinct, had low (1.9%) pollen fertility and failed to produce selfed or backcrossed seed. Given the abundance of C. bursa-pastoris along field margins, hybrids will likely be generated in the wild, but they will be unable to establish lineages unless fertility is restored. The large number of crosses and the diversity captured by the use of multiple accessions resulted in strong statistical power and a high degree of confidence in the estimated hybridization rate.

The development of the proembryo of rape Brassica napus L. from the zygote to the young embryo proper is described. A number of regularities were found in the direction, succession, and distribution of segmental and differentiating divisions of the proembryo. The direction of the divisions seems to foe determined by the direction of growth and the shape of the cells. The termyoung embryo proper is proposed to denote the globular embryo which already possesses separate plerome and periblem mother-cells and mother-cells of the iec layer and of clumella. The body of the embryo proper is derived from the apical cell ca which arose from the first division of the zygote and from the hypophysis - the only suspensor cell which closes the spheroid of the embryo. The development of the Brassica napus L. proembryo follows the sub-archetype Capsella bursa-pastoris in the IV megarchetype of Soueges.

We describe a new species of cyst-producing soil amoeba Vannella pentlandii from course pasture in the Pentland Hills, Scotland. Analysis of the 18S rDNA gene reveals that it belongs to the sub-group within the genus, presently composed of V. placida, V. epipetala and V. fimicola (the PEF group). This group share features such as longitudinal folds/ridges on the lamella (the anterior hyaline region of the trophozoite), stubby floating forms and cyst production. While each PEF species contain cyst producing strains, not all strains within these species do so. V. fimicola produces cysts on stalks leading to its former classification as a slime mould, however no such stalks were evident in the V. pentlandii , instead groups of cysts become piled on top of each other forming clumps. The encysting amoebae crawl toward each other, pushing some off the surface to form these mounds. The V. pentlandii trophozoites are of typical size for the genus but the cysts at 6.9 μm in diameter, are the smallest so far described in genus Vannella . Other cyst producing species are found in various branches within the Vannella phylogenetic tree, probably meaning that this ability was ancestral but lost in many branches (particularly in marine species), and perhaps re-gained in others.

Capsella rubella (C. rubella) is a highly selfing plant species, mostly occurring in southern and western Europe. As a member of the closest well-characterized genus (Capsella) to Arabidopsis thali...

To elucidate the evolutionary history of the genus Capsella , we included the hitherto poorly known species C. orientalis and C. thracica into our studies together with C. grandifl ora , C. rubella , and C. bursa-pastoris . We sequenced the ITS, and four loci of noncoding cpDNA regions (trnL – F, rps16, trnH – psbA, trnQ – rps16). In common garden fi eld experiments C. orientalis turned out as early fl owering with a specifi c leaf type. The crossing ability of the species was tested in pollen germination experiments. Capsella orientalis (self-compatible, SC; 2n = 16) forms a clade (eastern lineage) with C . bursa-pastoris (SC; 2n = 32), which is a sister clade (western lineage) to C. grandifl ora (self-incompatible, SI; 2n = 16) and C. rubella (SC; 2n = 16). Capsella bursa-pastoris is an autopolyploid species of multiple origin, whereas the Bulgarian endemic C. thracica (SC; 2n = 32) is allopolyploid and emerged from interspecifi c hybridisation between C. bursa-pastoris and C. grandifl ora . The common ancestor of the two lineages was diploid and SI, and its distribution ranged from eastern Europe to central Asia, predominantly confi ned to steppe like habitats. Biogeographic dynamics during the Pleistocene caused geographic and genetic subdivisions within the common ancestor giving rise to the two extant lineages. Capsella orientalis is verifi ed at several positions in western Mongolia.

Advances in phytoremediation research require the selection of new hyperaccumulators or accumulators and investigations of their tolerance and accumulation of heavy metals. Two concentration gradient experiments (preliminary and verification), involving the same soil Cd concentrations (0, 25, 50, 75, 100, and 125 mg kg−1), were conducted to study Cd accumulation and tolerance in Capsella bursa-pastoris. In the preliminary and verification concentration gradient experiments, the Cd content in shoots of C. bursa-pastoris exceeded 100 mg kg−1 at a soil Cd concentration of 50 mg kg−1, and the maxima of Cd contents in shoots were 307.67 and 369.20 mg kg−1 at 125 mg kg−1 Cd in soil, respectively. The shoot bioconcentration factor of C. bursa-pastoris was greater than 1, but the translocation factor was less than 1.0 in the preliminary and verification concentration gradient experiments. In the verification concentration gradient experiment, the malondialdehyde content and the activities of superoxide dismutase, peroxidase, and catalase increased compared with the control. Therefore, C. bursa-pastoris is a Cd-accumulator with strong tolerance to Cd, and could be used to remediate Cd-contaminated farmland soil in winter. © 2014 American Institute of Chemical Engineers Environ Prog, 2014 34: 663–668, 2015

The studies were caried out to determine the importance of some weeds occurrence in the flax monoculture the survival of Fusarium oxysporum f. sp. lini. It appearet that the roots of Veronica persica, Stellaria media, Lamium purpureum, Capsella bursa-pastoris and Sonchus arvensis were colonized by Fusarium oxysporum f. sp. lini. V. persica especially has, a profitable influence on the survival of F. oxysporum f. sp. lini. However. C. hursa-pastoris and S. arvensis stimulate the growth of fungi of the genera Trichoderma. which limites the occurrence of F. oxysporum f. sp. lini in the soil.

Plant cells respond to cold stress via a regulatory mechanism leading to enhanced cold acclimation accompanied by growth retardation. The C-repeat binding factor (CBF) signaling pathway is essential for cold response of flowering plants. Our previously study documented a novel CBF-like gene from the cold-tolerant Capsella bursa-pastoris named CbCBF, which was responsive to chilling temperatures. Here, we show that CbCBF expression is obviously responsive to chilling, freezing, abscisic acid, gibberellic acid (GA), indoleacetic acid or methyl jasmonate treatments and that the CbCBF:GFP fusion protein was localized to the nucleus. In addition, CbCBF overexpression conferred to the cold-sensitive tobacco plants enhanced tolerance to chilling and freezing, as well as dwarfism and delayed flowering. The leaf cells of CbCBF overexpression tobacco lines attained smaller sizes and underwent delayed cell division with reduced expression of cyclin D genes. The dwarfism of CbCBF transformants can be partially restored by GA application. Consistently, CbCBF overexpression reduced the bioactive gibberellin contents and disturbed the expression of gibberellin metabolic genes in tobacco. Meanwhile, cold induced CbCBF expression and cold tolerance in C. bursa-pastoris are reduced by GA. We conclude that CbCBF confers cold resistance and growth inhibition to tobacco cells by interacting with gibberellin and cell cycle pathways, likely through activation of downstream target genes.

Pollen was analysed in 30 unifloral Euphorbia honey samples from the Ifni Massif Region (Anti Atlas, Morocco). The honey samples were directly provided by beekeepers. The quantitative analyis showed that nectar is the main honey source in the samples studied. The qualitative analysis of the samples showed the presence of 35 taxa belonging to 17 families. The Moroccan Euphorbia honeys of the studied region are characterized by their low—medium number of pollen grains (NGP; mean = 5700), 76% of the honeys belong to Class I and II of Maurizio, and by their low honeydew indicator (HDE/NGPn 90% of the samples, followed by Bellis sp., Capsella f. and Reseda sp. (85%). However, for the E. regis-jubae honeys, the most characteristic accompanying species are Crepis f., present in 100% of the samples.

Evolutive changes in mating systems are often accompanied by changes in flower morphology, such as the reduction in size or even loss of petals, changes in production of volatiles, pollen/ovule ratio, the position between anthers and stigma and the germination time of pollen after pollination. These changes have been merged under the term “selfing syndrome” and often result in new taxonomic species. The evolutionary shift frequently happens parallel within many families and genera, for example within the Brassicaceae family. Within the genus Capsella , which is closely related to the molecular model species pair Arabidopsis lyrata (SI)/ A. thaliana (SC), we studied self-incompatible and self-compatible species. SC species C. rubella and C. bursa-pastoris produce in comparison with the SI species C. grandiflora (i) smaller petals as the result of decreased cell division and only less of decreasing cell volume, (ii) less production of pollen in one flower, (iii) show a lesser incision between the two valves of the fruits, in combination with a shorter style, and (iv) have a much quicker fertilization of SC pollen after pollination. Crossing success between the diploid species, between different provenances of the tetraploid C. bursa-pastoris , and between the two diploid species and particular individuals of the self-incompatible C. grandiflora has been proven.

The sulforaphane content of various edible plants, as well as the bioactivity of this compound, has been researched extensively in recent times. The purpose of this study was to examine the sulforaphane content in Korean shepherd’s purse (Capsella bursa-pastoris L. Medik) and related species and its anti-inflammatory effects. The sulforaphane contents in seeds from 8 different species closely related to Korean shepherd’s purse species were analyzed by LC-electrospray tandem mass spectrometry (LC-MS/MS). The highest concentration of sulforaphane (70.0±2.1 μg/g) was found in American yellowrocket (Barbarea orthoceras), while the lowest (22.8±4.7 μg/g) was found in jobsalnaengi (Cardamine flexuosa var. fallax). The extracts from the American yellowrocket and wavy bittercress (Cardamine flexuosa) species, which were found to contain high sulforaphane concentrations, reduced lipopolysaccharide-induced nitric oxide production in BV-2 microglial cells. These results suggest that Korean Brassicaceae species exhibit anti-inflammatory properties in BV-2 microglial cells, and that this might have potential preventative for various neurodegenerative diseases.

Camelina [i](Camelina sativa[/i] (L.) Crantz) is a re-emergent oilseed crop that is also becoming important as a model for applied projects based on studies in[i] Arabidopsis thaliana[/i], since the two species are closely related members of the tribe [i]Camelineae[/i] of the Brassicaeae. Since camelina can be transformed genetically by floral dip, genetically modified (GM) camelina is being created in many laboratories, and small-scale field trials are already being conducted in the US and Canada. Although camelina does not cross-fertilize [i]Brassica[/i] crop species, such as oilseed rape, nothing was known about its ability to cross with other members of the tribe Camelineae, which in addition to arabidopsis includes the widespread weed, shepherd's purse ([i]Capsella bursa-pastoris[/i]). We have tested the ability of camelina to cross with arabidopsis and [i]C. bursa-pastoris[/i], as well as with the more distantly related Cardamine hirsuta, tribe cardamineae. No seeds were produced in crosses with arabidopsis, and a few seeds were obtained in crosses with [i]C. hirsuta[/i], but the embryos aborted at an early stage of development. A few seeds were also obtained in crosses with[i] C. bursa-pastoris[/i], which germinated to produce plants of a phenotype intermediate to that of the parents, but the hybrids were both male and female sterile. Therefore, the likelihood of pollen-mediated gene flow from camelina to these related species is low.

Downy mildew of crucifers is caused by an obligate pathogen, Hyaloperonospora parasitica (Gaum.) Goker synonymy Peronospora parasitica (Pers. ex. Fr.) Fr. The genus Peronospora s. lat. is one of the largest genera of downy mildews (Peronosporales, Peronosporomycetes, phylum Heterokonta). Recently, phylogenetic analyses of DNA sequences have received increasing attention in Peronosporales, opening a new era in the investigation of their phylogenetic relationships. Both genera Hyaloperonospora and Perofascia almost exclusively infect hosts in the Brassicaceae and related families. The genera were segregated from Peronospora due to pronounced morphological and molecular differences. The earliest reference of downy mildew on crucifers is by Persoon (1796) who described the cause of the disease on Capsella bursa-pastoris to the fungus Botrytis parasitica Pers. Recently, researchers presented molecular and morphological evidence to split Peronospora into three separate genera, Peronospora s. str., Hyaloperonospora, and Perofascia, and the latter two genera were found to be entirely restricted to a single host family, Brassicaceae.

We examined morphological and genetic differences among Aceria spp. inhabiting six Brassicaceae species in Serbia. Five of them have been already mentioned in the literature as original or alternate hosts of Aceria spp. (Berteroa incana (L.) DC., Capsella bursa-pastoris (L.) Medik., Cardamine hirsuta L., Lepidium draba L. and Sisymbrium orientale L.), whereas Aurinia petraea (Ard.) Schur was registered here for the first time as a host for Aceria sp. Results of morphometric analyses indicated clear differentiation of Aceria spp. from B. incana, L. draba, A. petraea and S. orientale, whereas the other two entities were less diverse and clustered together. Molecular analyses indicated that the average mean divergence over all sequence pairs was 18.3% (11.8–25.9%) and disclosed that the observed mtCOI distances between the six host-associated Aceria entities are large enough to represent differences between species. The Aceria sp. hosted by B. incana was morphologically and genetically most distinctive, whereas discrepancy between phenetic and phylogenetic relationships was found in the position of Aceria sp. hosted by L. draba when compared with those inhabiting C. hirsuta, S. orientale and C. bursa-pastoris. Experimental and Applied Acarology (2017), 71(4): 329-343

The outer surface of myxospermous seed coats contains mucilage which absorbs large amounts of water relative to its dry weight. Ecologically, the seed mucilage can affect seed germination and dormancy. Upon hydration, a large proportion of the seed mucilage is lost to the soil and the physics of soil-seed mucilage interactions has not been assessed. Towards that end, the dynamic rheological properties of mucilage extracted from Capsella bursa-pastoris L. Medik. (shepherd's purse) seeds were assessed as a function of mucilage concentration (1-10% (w/w)), temperature (0-80 ◦ C) and shear frequency (0.1- 100 rad s −1 ). The seed mucilage was shear thinning and was classified as a highly viscous "weak gel". The relationship between the viscoelastic parameters (viscosity, η ∗ , storage and loss modulus, Gand G �� , yield and flow stresses, τy and τf ) and mucilage concentration were well fitted by power law models. The values of η ∗ , Gand G �� increased as temperature increased above 40 ◦ C and were also slightly frequency dependent. The shepherd's purse seed mucilage is more viscous than that from other plant parts, such as fruits and roots. These properties highlight the possibility that seed mucilage may affect soil conditions and therefore present an additional facilitative ecological role (beyond that already reported, which directly affect seed biology); and this is discussed.

Цитологические исследования проведены на 12 видах семейства Brassicaceae Burn. из популяций различных географических зон Западных Гималаев. Определены хромосомные числа для Barbaraea intermedia (n = 16), Cardamine loxostemonoides (n = 8), Nasturtium officinale (n = 8), Sisymbrium orientale (n = 14) и добавлены к известным сведениям об этих видах. Хромосомные числа семи видов, Barbaraea intermedia (n = 8), B. vulgaris (n = 8), Capsella bursa-pastoris (n = 8), Descuriania sophia (n = 10), Rorippa islandica (n = 8), Sisymbrium strictum (n = 7) и Thlaspi alpestre (n = 7), были определены впервые в Индии. Течение мейоза в популяциях семи видов (Barbaraea intermedia, Capsella bursa-pastoris, Coronopus didymus, Descuriania sophia, Nasturtium officinale, Sisymbrium orientale и S. strictum) изменяется от нормального до аномального, в то время как в популяциях Barbaraea vulgaris и Sisymbrium irio наблюдается аномальный ход мейоза. Мейотические аномалии проявляются в виде цитомиксиса, слипшихся хромосом, дезориентированных бивалентов, межбивалентных соединений, формировании отставших хромосом и мостов, что в целом приводит к нарушениям микроспорогенеза. Гетерогенные по размеру фертильные пыльцевые зерна и сниженный репродукционный потенциал наблюдались во всех мейотически аномальных популяціях. В то же время ход мейоза во всех популяциях Cardamine loxostemonoides, Rorippa islandica и Thalspi alpestre был нормальным и сопровождался высокой фертильностью пыльцы. Цитологічні дослідження проведені на 12 видах родини Brassicaceae Burn. з популяцій різних географічних зон Західних Гімалаїв. Визначені хромосомні числа для Barbaraea intermedia (n = 16), Cardamine loxostemonoides (n = 8), Nasturtium officinale (n = 8), Sisymbrium orientale (n = 14) і додані до відомостей про ці види. Хромосомні числа семи видів, Barbaraea intermedia (n = 8), B. vulgaris (n = 8), Capsella bursa-pastoris (n = 8), Descuriania sophia (n = 10), Rorippa islandica (n = 8), Sisymbrium strictum (n= 7) та Thlaspi alpestre (n = 7), були визначені вперше в Індії. Проходження мейозу в популяціях семи видів (Barbaraea intermedia, Capsella bursa-pastoris, Coronopus didymus, Descuriania sophia, Nasturtium officinale, Sisymbrium orientale і S. strictum) змінюється від нормального до аномального, тоді як в популяціях Barbaraea vulgaris і Sisymbrium irio спостерігається аномальний хід мейозу. Мейотичні аномалії проявляються у вигляді цитоміксису, злиплих хромосом, дезорієнтованих бівалентів, міжбівалентних сполук, формуванні відсталих хромосом і мостів, що в цілому призводить до порушень мікроспорогенезу. Гетерогенні за розміром фертильні пилкові зерна та знижений репродукційний потенціал спостерігалися в усіх мейотично аномальних популяціях. В той же час хід мейозу в усіх популяціях Cardamine loxostemonoides, Rorippa islandica і Thalspi alpestre був нормальним і супроводжувався високою фертильністю пилку. Cytological studies have been carried out on 12 species of Brassicaceae Burn. on population basis from different geographical areas of Kashmir and Himachal Pradesh in the Western Himalayas. Variable chromosome reports for Barbaraea intermedia (n = 16), Cardamine loxostemonoides (n = 8), Nasturtium officinale (n = 8), Sisymbrium orientale (n = 14) on world-wide basis have been added to the previous reports of these species. The chromosome numbers in seven species as Barbaraea intermedia (n = 8), B. vulgaris (n = 8), Capsella bursa-pastoris (n = 8), Descuriania sophia (n = 10), Rorippa islandica (n = 8), Sisymbrium strictum (n = 7) and Thlaspi alpestre (n = 7) have been worked out for the first time from India. The meiotic course in the populations of seven species such as Barbaraea intermedia, Capsella bursa-pastoris, Coronopus didymus, Descuriania sophia, Nasturtium officinale, Sisymbrium orientale and S. strictum varies from normal to abnormal while all the populations of two species Barbaraea vulgaris and Sisymbrium irio show abnormal meiotic course. Meiotic abnormalities are in the form of cytomixis, chromosomal stickiness, unoriented bivalents, inter-bivalent connections, formation of laggards and bridges, all resulting into abnormal microsporogenesis. Heterogenous sized fertile pollen grains and reduced reproductive potentialities have invariably been observed in all the meiotically abnormal populations. However, the meiotic course in all the populations of Cardamine loxostemonoides, Rorippa islandica and Thalspi alpestre is found to be normal with high pollen fertility.

Low temperature is among the most significant abiotic stresses, restricting the habitats of sessile plants and reducing crop productivity. Cold regulated (COR) genes are low temperature-responsive genes expressing under regulation of a specific signal transduction pathway, which is designated C-repeat-binding-factor (CBF) signaling pathway. In the present article, cold bioassay showed that the transcript level of cold regulated gene CbCOR15b from shepherd's purse (Capsella bursa-pastoris) was obviously elevated under cold treatments. Reverse transcription-PCR (RT-PCR) and GUS report system revealed that unlike AtCOR15b, CbCOR15b expressed not only in leaves but also in stems and maturation zone of roots. When transgenic tobacco plants ectopically expressing CbCOR15b were exposed to chilling and freezing temperatures, they displayed more cold tolerance compared to control plants. According to the electrolyte leakage, the relative water content, the glucose content and the phenotype observation, CbCOR15b transformants suffered less damage under cold stress. Further investigation of the subcellular localization of CbCOR15b by transient expression of fusion protein CbCOR15b–GFP revealed that it was localized exclusively in the chloroplasts of tobacco mesophyll cells and in the cytoplasm of onion epidermal cells. It can be concluded that CbCOR15b which located in the chloroplasts and in the cytoplasm of cells without chloroplasts was involved in cold response of C. bursa-pastoris and conferred enhanced cold tolerance in transgenic tobacco plants.

Van Acker, R. C. and Cici, S. Z. H. 2012. Short Communication: Timing of stinkweed and shepherd's-purserecruitment affects biological characteristics of progeny. Can. J. Plant Sci. 92: 933–936. The effect of recruitment timing (fall versus spring recruitment) on seed characteristics and performance of two common Canadian facultative winter annual weeds; stinkweed (Thlaspi arvense L.) and shepherd's-purse (Capsella bursa-pastoris L.) was investigated. Seed germination proportion was unaffected by maternal emergence timing but germination was faster for spring versus winter cohort seeds of stinkweed. Proportionally more seeds from winter (fall-recruited) cohorts were rendered non-viable by aging treatments, while for shepherd's purse, aging treatments broke dormancy instead of reducing viability and this was especially true for winter cohort seeds. For both weed species, spring cohort seeds produced earlier flowering plants with greater and lesser biomass allocation to reproductive tissues and roots, respectively. These results show the potential importance of germination timing and maternal effects on weed populations and demonstrate additional complexity in the nature of facultative winter annual weeds, in particular.

The increasing use of AHAS-inhibiting herbicides has resulted in evolved resistance in key dicot weeds infesting cereal cropping systems worldwide. Shepherd’s purse (Capsella bursa-pastoris) is a common dicot weed species in wheat in China with populations that have evolved resistance to the AHAS herbicide tribenuron-methyl. The seeds of eight resistant populations were collected from wheat fields and one susceptible population from road side in Hebei province of China. All eight populations showed high level resistance to tribenuron-methyl with resistance indices of over 100 fold based on whole plant dose response assays in the greenhouse. Comparison of the AHAS gene sequences of the susceptible and resistant populations with Arabidopsis revealed that proline at position 197 of the AHAS gene was substituted by threonine in population CAPBU-HB-2, serine in populations CAPBU-HB-3, CAPBU-HB-4, CAPBU-HB-5, and CAPBU-HB-6, leucine in population CAPBU-HB-7 and CAPBU-HB-8, histidine in population CAPBU-HB-9. The study confirmed tribenuron-methyl resistance in shepherd’s purse in Hebei province of China due to target site mutations at AHAS codon position 197.

†Background and Aims Myxospermy is a term which describes the ability of a seed to produce mucilage upon hydration. The mucilage is mainly comprised of plant cell-wall polysaccharides which are deposited during development of those cells that comprise the seed coat (testa). Myxospermy is more prevalent among those plant species adapted to surviving on arid sandy soils, though its significance in determining the ecological fitness of plants is unclear. In this study, the first mathematical model of myxospermous seed mucilage expansion is presented based on seeds of the model plant species Capsella bursa-pastoris (shepherd’s purse). †Methods The structures underpinning the expansion process were described using light, electron and time-lapse confocal micrographs. The data and experimental observations were used to create a mathematical model of myxospermous seed mucilage expansion based on diffusion equations. †Key Results The mucilage expansion was rapid, taking 5 s, during which the cell mucilage volume increased 75-fold. At the level of the seed, this represented a 6-fold increase in seed volume and a 2.5-fold increase in seed surface area. These increases were shown to be a function of water uptake (16 g water g 21 mucilage dry weight), and relaxation of the polymers which comprised the mucilage. In addition, the osmotic pressure of the seed mucilage, estimated by assessing the mucilage expansion of seeds hydrated in solutions of varying osmotic pressure, was ‐0.54 MPa (equivalent to 0.11 M or 6. 6g L 21 NaCl). †Conclusions The results showed that the mucilage may be characterized as hydrogel and seed-mucilage expansion may be modelled using the diffusion equation described. The potential of myxospermous seeds to affect the ecological services provided by soil is discussed briefly.

This study examined larval food habits of two syntopic, related, carabids Amara chalcites Dejean and A. congrua Morawitz using a laboratory-rearing experiment, and the results were compared with those of a previous stable-isotope analyses of the same species. Larvae were reared on six different diets (seeds of Capsella bursa-pastoris (Linnaeus) Medikus, Stellaria media (Linnaeus) Villars, Taraxacum officinale Weber ex Wiggers; mixed seeds; Tenebrio molitor Linnaeus larvae; and Tenebrio larvae + mixed seeds). For both species, beetles fed seed diets exhibited moderate to high survival rates, with the exception of those fed Stellaria seeds, on which A. congrua showed low survival rates. The pure-animal diet resulted in high survival rates of A. chalcites but low survival rates of A. congrua. These results were consistent with those of the isotope analysis, in which A. chalcites larvae were more carnivorous than were A. congrua larvae, and the larvae of the two species appeared to prefer different types of seeds. In contrast, the effect of diet on adult weight differed between the two methods. In the laboratory experiments, supplementing seeds with animal food during the larval stage positively affected adult weight for both species, whereas in the isotope analysis, the positive effect only occurred in A. chalcites. Possible explanations for the discrepancy between the two methods and suggestions for future research are provided.

Capsella bursa-pastoris, a winter annual weed in the mustard family, can not be controlled by tribenuron after the herbicide has been continuously used for several years. The resistant biotype Lz-R was the generation of a population collected from Liangzhu, a place where tribenuron had been used for more than 15 consecutive years. To confirm and characterize the resistance of C. bursa-pastoris to tribenuron, whole-plant bioassays were conducted in the greenhouse. The results of whole-plant bioassays revealed that Lz-R was highly resistant to tribenuron with the resistance index (GR50 Lz-R)/(GR50 Lz-S) up to 236.6. To investigate the molecular basis of resistance in C. bursa-pastoris, the acetolactate synthase (ALS) genes were sequenced and compared between susceptible and resistant biotypes. Analysis of the nucleotide and deduced amino acid sequences between the biotypes indicated that one substitution had occurred in Domain A, cytosine by thymine (CCT to TCT) at position 197, that led to a change of the amino acid proline in the susceptible to serine in the Lz-R.