Gut-specific actinobacterial community structure and diversity associated with the wood-feeding termite species, Nasutitermes corniger (Motschulsky) described by nested PCR-DGGE analysis

This comprehensive survey studied the actinobacterial community structure and putative representative members associated with the gut of the wood-feeding termite, Nasutitermes corniger (Motschulsky), using nested PCR-DGGE and 16S rDNA sequences analyses. The closest relatives of the actinobacteria inhabiting the gut of Nasutitermes corniger were in five families, regardless of the geographical origin of the termite colony: Propionibacteriaceae, Streptomycetaceae, Cellulomonodaceae, Corynebacteriaceae and Rubrobacteraceae. Feeding termites on beech wood did not result in substantial changes in the actinobacterial community structure as revealed by DGGE banding patterns. Most of the 16S rDNA sequences obtained after excision and sequencing of DGGE bands clustered with those previously retrieved in termite guts. These results confirm the presence of gut-specific actinobacteria. Except for the 16S rDNA sequences affiliated to Streptomycetaceae and Cellulomonodaceae, no sequence had more than 97% similarity with the closest isolated strains, indicating the presence of microorganisms that have not yet been cultivated. These results suggest that members of the Actinomycetales order account for the largest proportion of the Actinobacteria phylum inhabiting the gut of the termite N. corniger.     

The role of pheromones in the initiation of foraging, recruitment and defence by the soldiers of a tropical termite, Nasutitermes corniger (Motschulsky)

The polyethic behaviour of soldiers and workers of Nasutitermescorniger during foraging and in defence is described. It hasbeen shown that the cephalic gland defensive secretion of thenasute soldiers produces short term recruitment of only soldiersto loci where it is present. Without further reinforcement ofthe stimulus, the number of soldiers wanes. Workers react tothe cephalic gland secretion by remaining in or retreating tothe nest. The sternal gland secretion of workers and soldiersacts in long term recruitment of soldiers when presented experimentallyas a point source, as a trail or as a trail with a food sourceat its end. This secretion causes more exiting soldiers thanthe cephalic gland secretion, and is more effective in thisregard as a trail than as a point source. The greater numbersexiting in the trail situation appears to be related to thegreater amount of pheromone area present, and the halting ofsoldiers at the pheromone odour boundary. The greatest numberof soldiers exit when the trail is coupled with a food sourceat its end, and in this situation workers exit for the firsttime in significant numbers. Additional information about thefood source is postulated to be communicated by tactile means(jittering) and it is suggested that this lowers the thresholdfor the trail following responses in the termites such thatworker exiting is initiated. Other factors affecting the numbersforaging are noted. The phenomenon of soldier initiation offoraging as scouts, and as a scouting column, is commented onwith regard to the polyethic responses to the pheromones, andto its adaptive significance (sociobiological import) in thelight of the soldiers' rôle in colony defence.     

Optimization of aqueous-assisted extraction of polysaccharides from pumpkin (Cucurbita moschata Duch) and their biological activities

The pumpkin pulp contains a greater composition of edible polysaccharides and has reported with excellent biological applications. This research pertains to optimize the extraction of polysaccharides from the fleshy portion of the pumpkin using aqueous assisted extraction (AAE). The result showed that the optimal extraction condition of pumpkin polysaccharide was as follows: extraction temperature at 55 °C, pH 4.5, and enzyme concentration of 4000 µ/g for 80 min. Under the optimal extraction condition, the yield of pumpkin polysaccharide via AAE (15.4) was significantly higher. The biological activities of extracted polysaccharide including α-amylase inhibition (57.41% at 1000 µg/mL) and anti-inflammatory (50.41% at 25 µg/mL) activity increased significantly. Additionally, the antioxidant activities of extracted pumpkin polysaccharides including IC₅₀ values of DPPH and ABTS were 59.87% and 58.74%, respectively. The pumpkin polysaccharide has maximum inhibitory effects against bacterial strains especially for Escherichia coli than that of fungal strains. It is suggested that the aqueous assisted extraction of is a cost-effective promising method to decrease the processing time as well as enhancing extracted polysaccharide yield – times.     

Chromatographic profiles and antimicrobial activity of the essential oils obtained from some species and cultivars of the Mentheae tribe (Lamiaceae)

The present study was focused on the chemical composition and antimicrobial activity of the essential oils (EsO) obtained from five Lamiaceae representatives grown in the south of Ukraine. Among them are Salvia sclarea L., Monarda didyma (cultivar ‘Cambridge Scarlet’), Thymus pulegioides (cultivar ‘2/6-07’), Thymus vulgaris (cultivar ‘Jalos’), and Thymus serpyllum L. The component analysis of the EsO was carried out by gas chromatography method coupled with mass spectrometry (GC–MS). The antimicrobial properties of the EsO were determined using the agar diffusion test against widespread pathogenic bacterial strains (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Streptococcus pyogenes) and opportunistic yeast Candida albicans. The EsO of Thymus serpyllum and Thymus vulgaris (cultivar ‘Jalos’) displayed noteworthy antibacterial properties against a wide spectrum of the microorganisms. These antimicrobial properties could be attributed to the high content of aromatic monoterpenoid thymol (52.56% and 47.33%, respectively). The EsO of Salvia sclarea with the dominance of linalyl acetate (45.51%) and linalool (38.98%) as well as Thymus pulegioides (cultivar ‘2/6-07’) containing α-citral (27.10%) and β-citral (17.11%) demonstrated the strongest antimicrobial effects on typical and clinical strains of Staphylococcus aureus with the inhibition zones in the range of 24.0–31.0 mm. The Salvia sclarea EsO demonstrated the most significant effect against clinical strains of Candida albicans. In conclusion, the present study revealed the chemical composition of five Lamiaceae species and cultivars grown in the south of Ukraine and considerable antimicrobial activity of the tested EsO, especially against the typical and clinical strains of Staphylococcus aureus and Candida albicans. The obtained results could be perspective for applying in the pharmaceutical industry and for the conservation of food and cosmetic products.     

黄鳍金枪鱼抗菌肽YFGAP在大肠杆菌中融合表达及其活性检测

【目的】抗菌肽YFGAP由32个氨基酸组成,分子量为3.4 kD,对革兰氏阳性菌(G+)和革兰氏阴性菌(G?)表现出强效的抑制作用,不具有溶血活性。在大肠杆菌中表达抗菌肽YFGAP,分离纯化抗菌肽并鉴定其生物学活性。【方法】化学合成EK-YFGAP和L-EK-YFGAP基因序列,构建表达载体pET22b-ELP20-EK-YFGAP、pET22b-ELP40-EK-YFGAP和pET22b-ELP40-L-EK- YFGAP,分别转化至大肠杆菌BL21(DE3)中诱导表达,可逆相变循环纯化融合蛋白。肠激酶酶切,经Vivaspin Turbo纯化柱纯化,测定重组抗菌肽的抑菌活性和溶血活性。【结果】纯化出两种融合蛋白ELP40-EK-YFGAP和ELP40-L-EK-YFGAP,肠激酶酶切纯化后获得重组抗菌肽YFGAP,对4种病原菌均有抑制效果,溶血活性较低。【结论】以ELPs作为非色谱纯化标签,实现了抗菌肽YFGAP的融合表达,具有操作简单、成本低、易于扩大的优势,为重组抗菌肽的量化制备及应用提供了理论基础和技术支持。     

Genetic localization of a bruchid resistance gene and its relationship to insecticidal cyclopeptide alkaloids, the vignatic acids, in mungbean ( Vigna radiata L. Wilczek)

Bruchid resistance, controlled by a single dominant gene (Br) in a wild mungbean accession (TC1966), has been incorporated into cultivated mungbean (Vigna radiata). The resistance gene simultaneously confers inhibitory activity against the bean bug, Riptortus clavatus Thunberg (Hemiptera: Alydidae). The resultant isogenic line (BC₂₀ generation) was characterized by the presence of a group of novel cyclopeptide alkaloids, called vignatic acids. A linkage map was constructed for Br and the vignatic acid gene (Va) using restriction fragment length polymorphism (RFLP) markers and a segregating BC₂₀F₂ population. By screening resistant and susceptible parental lines with 479 primers, eight randomly amplified polymorphic DNA (RAPD) markers linked to Br were identified and cloned for use as RFLP probes. All eight RAPD-based markers, one mungbean, and four common bean genomic clones were effectively integrated around Br within a 3.7-cM interval. Br was mapped to a 0.7-cM segment between a cluster consisting of six markers and a common bean RFLP marker, Bng110. The six markers are closest to the bruchid resistance gene, approximately 0.2 cM away. The vignatic acid gene, Va, cosegregated with bruchid resistance. However, one individual was identified in the BC₂₀F₂ population that retained vignatic acids in spite of its bruchid susceptibility. Consequently, Va was mapped to a single locus at the same position as the cluster of markers and 0.2 cM away from Br. These results suggest that the vignatic acids are not the principal factors responsible for bruchid resistance in V. radiata but will facilitate the use of map-based cloning strategies to isolate the Br gene. Received: 20 November 1997 / Accepted: 6 January 1998     

Resistance,its stability and reversion rate of resistance to imidacloprid,indoxacarb and chlorfenapyr in a field population of green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae)

Abstract

Green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a valuable bio-control agent that predates over various insect pests with high efficacy. It has developed considerable resistance to different classes of insecticides. This study was planned to investigate resistance level, stability and reversion rate against some new chemical insecticides using a field collected population of C. carnea. Field collected strain of C. carnea showed 313.44-fold, 216.50-fold and 276.83-fold resistance to imidacloprid, indoxacarb and chlorfenapyr compared to susceptible population, respectively. Baseline susceptibility values of C. carnea to imidacloprid, indoxacarb and chlorfenapyr were 2627.31, 502.10 and 581.89?ppm, while the insecticide resistance decrease rate was ?0.039, ?0.048 and ?0.040, respectively. Rotation of these insecticides requires quality measures maintaining survival of C. carnea in an intense environment where repeated applications are required to avoid economic damage by pests.     

Status and preliminary mechanism of resistance to insecticides in a field strain of housefly (Musca domestica,L)

Resistance profiles of houseflies (Gol-RR) collected from a field in Golmud city, Qinghai province, China, were determined for seven insecticides using topical bioassays. Resistance ratios of >1219.51, 153.17, >35.43, 6.12, 3.24, 1.73, and 0.86-fold were obtained for propoxur, cypermethrin, imidacloprid, indoxacarb, chlorpyrifos, fipronil, and chlorfenapyr, respectively, relative to a laboratory susceptible strain (SS). Synergism experiments showed that piperonyl butoxide (PBO), triphenylphosphate (TPP), and diethyl maleate (DEM) increased propoxur toxicity by >105.71, >7.88, and >5.15-fold in the Gol-RR strain, compared with 5.25, 2.00, and 1.39-fold in the SS strain, indicating the involvement of P450 monooxygenases, esterases, and glutathione-S-transferase in conferring resistance. Although cypermethrin resistance was significantly suppressed with PBO, TPP, and DEM in the Gol-RR strain, the synergistic potential of these agents to cypermethrin was similar in the SS strain, demonstrating that metabolism-mediated detoxification was not important for conferring resistance to cypermethrin in the Gol-RR strain. However, the three agents did not act synergistically with imidacloprid, indicating that other mechanisms may be responsible for the development of resistance to this insecticide. Acetylcholinesterase (AChE) activity was 13.70-fold higher in the Gol-RR than in the SS strain, suggesting the properties of the AChE enzyme were altered in the Gol-RR strain. Thus, rotation of chlorfenapyr insecticide with other agents acting through a different mode with minimal/no resistance could be an effective resistance management strategy for housefly.     

Antibiotic resistance and survival of faecal coliforms in activated sludge system in a semi-arid region (Beni Mellal,Morocco)

The activated sludge process is one of the biological treatment methods used in many countries to reduce the high levels of organic and mineral pollutants and pathogenic micro-organisms present in wastewater. The present work was undertaken to study the dynamic and antibiotic-resistance of faecal coliforms (FC) in the activated sludge system of Beni Mellal. This work has also as objective the study of the survival of FC, protozoan cysts, helminth eggs and FC antibiotic resistance in the sludge dehydrated in drying beds in order to know if the agricultural usage of sludge presents any problems to public health. The activated sludge treatment of Beni Mellal resulted in an average reduction of FC and faecal streptococci of 90.75 and 91.06%, respectively. The overall resistance (resistance to at least one antibiotic) of 111 FC strains isolated from the system was 72.07%. This treatment system did not increase the incidence of FC antibiotic resistance in treated wastewaters. The antibiotic resistance of FC was found to be similar in both raw (71.05%) and treated sewage (77.77%). High levels of antibiotic resistance were towards streptomycin (54.05%), ampicillin (42.34%), amoxicillin (42.34%) and amoxicillin–clavulanic acid (31.53%). The treatment of sludge in drying beds appeared to be efficient in eliminating pathogenic micro-organisms: FC, protozoan cysts and helminth eggs. Moreover, the FC antibiotic resistance did not change over time in sludge-drying bed. According to the standard norms, agricultural utilization of this sludge cannot be excluded. However, it is important to study in the receptor environment the survival and the behaviour of antibiotic-resistant FC present in sludge and water.     

Phytotoxic Effects and Phytochemical Fingerprinting of Hydrodistilled Oil,Enriched Fractions,and Isolated Compounds Obtained from Cryptocarya massoy (Oken) Kosterm. Bark

The hydrodistilled oil of Cryptocarya massoy bark was characterized by GC‐FID and GC/MS analyses, allowing the identification of unusual C₁₀ massoia lactone ( 3 , 56.2%), C₁₂ massoia lactone ( 4 , 16.5%), benzyl benzoate ( 1 , 12.7%), C₈ massoia lactone (3.4%), δ‐decalactone ( 5 , 1.5%), and benzyl salicylate ( 2 , 1.8%) as main constituents. The phytotoxic activities of the oil, three enriched fractions (lactone‐rich, ester‐rich, and sesquiterpene‐rich), and four constituents (compounds 1, 2, 5 , and δ‐dodecalactone ( 6 )) against Lycopersicon esculentum and Cucumis sativus seeds and seedlings were screened. At a concentration of 1000 μl/l, the essential oil and the massoia lactone‐rich fraction caused a complete inhibition of the germination of both seeds, and, when applied on tomato plantlets, they induced an 85 and 100% dieback, respectively. These performances exceeded those of the well‐known phytotoxic essential oils of Syzygium aromaticum and Cymbopogon citratus, already used in commercial products for the weed and pest management. The same substances were also evaluated against four phytopathogenic bacteria and ten phytopathogenic fungi, providing EC₅₀ values against the most susceptible strains in the 100–500 μl/l range for the essential oil and in the 10–50 μl/l range for compound 6 and the lactone‐rich fraction. The phytotoxic behavior was related mainly to massoia lactones and benzyl esters, while a greater amount of 6 may infer a good activity against some phytopathogenic fungi. Further investigations of these secondary metabolites are warranted, to evaluate their use as natural herbicides.     

Analysis of the chemical composition of root essential oil from Indian sarsaparilla (Hemidesmus indicus) and its application as an ecofriendly insecticide and pharmacological agent

The Indian sarsaparilla (Hemidesmus indicus) is a commonly used plant in Indian traditional medicine of Ayurveda for the preparation of various non-alcoholic beverages. However, limited studies are available on the essential oil of H. indicus roots (HRO); therefore, the study evaluated the antioxidant, anti-inflammatory and antidiabetic activities of H. indicus root essential oil as well as insecticide potential against the common pests of stored food materials (Sitophilus oryzae, Callosobruchus maculatus and Tribolium castaneum). The repellant efficacy of HRO was found to be high against S. oryzae (8.21 ± 0.55 μg/mL). Likewise, the fumigant potential was also observed for HRO against these pests; the higher activities were observed against S. oryzae and C. maculatus (32.46 ± 1.42 and 35.18 ± 1.62 μg/L). Besides, the essential oil was also found to be active as a contact poison, however, against all the three pests, the toxicity was above 100 μg/mm³, being the highest against C. maculatus (122.8 ± 3.57 μg/mm³). To analyze the possible effect of the essential oil on grains, the different grains were allowed to germinate and compared to that of normal; thus, the non-toxic nature of HRO against the stored products is also confirmed. The essential oil shown to have DPPH hydrogen peroxide and ABTS radical scavenging, nitric oxide scavenging potential, and inhibition of lipoxgenase, alpha-amylase and alpha-glucosidase. Overall, the present study concludes that the H. indicus may be a suitable repellant and fumigant agent against different pests of stored products and a possible antioxidant, anti-inflammatory, and anti-diabetic agent.     

河北转Bt基因棉田棉铃虫对杀虫剂的抗性及相关酶活性的变化

为明确河北省推广种植植转Bt基因抗虫棉（简称Bt棉）后, 棉铃虫Helicoverpa armigera (Hübner)对常用杀虫剂的抗药性水平及其生化机理, 2011-2012年采用点滴法对保定南郊、 沧州南皮、 邢台巨鹿3个地区的田间种群以及敏感种群进行了室内毒力测定, 并采用生化分析法对4个种群相关的羧酸酯酶（carboxylesterase, CarE）、 谷胱甘肽S 转移酶(glutathione S-transferases, GSTs)和乙酰胆碱酯酶(acetylcholinesterase, AChE)的活性进行了研究。结果表明: 3个田间种群对高效氯氰菊酯和氰戊菊酯处于中至高抗水平, 抗性倍数为20.02~73.70倍; 对灭多威处于低至中抗水平, 抗性倍数为6.27~11.84倍; 对高效氯氟氰菊酯(抗性倍数: 1.07~4.20倍), 辛硫磷、 毒死蜱和马拉硫磷(抗性倍数: 1.00~2.69倍), 以及氯虫苯甲酰胺（抗性倍数: 2.00~3.67倍）均处于敏感水平。3个田间种群的CarE, GSTs和AChE活性分别是敏感种群的1.06~1.23, 1.20~1.63和1.15~1.23倍, 这可能与其对高效氯氰菊酯、 氰戊菊酯和灭多威产生的抗性有关。     

Remating by female Mediterranean fruit flies (Ceratitis capitata, Diptera: Tephritidae): Temporal patterns and modulation by male condition

We determined the temporal pattern of female remating in the Mediterranean fruit fly, Ceratitis capitata, and how mating with sterile males affects remating. In addition, we examined the hypotheses that sterile male nutrition and age affect the subsequent receptivity of their mates. Temporally, female receptivity varied significantly throughout the experimental period. Relatively high levels of remating (14%) on the days following the first copulation were followed by a decline, with a significantly low point (4.1%) 2 weeks after mating. Subsequently, receptivity is gradually restored (18%) 3 and 4 weeks after the initial copulation. When females were first mated to sterile males, significantly higher remating percentages were recorded. The ability of sterile males to inhibit receptivity of both wild and laboratory reared females on the day of first mating was significantly improved when they were fed a nutrient rich diet. Male age at first mating also affected female receptivity: sterile males of intermediate age (11 days old) inhibited female remating significantly more than younger or older flies. Although further studies are needed to determine the relative roles of natural and sexual selection in modulating patterns of female sexual receptivity, the Sterile Insect Technique may be improved by releasing well nourished, older sterile males.     

Ochrosin,a new biosurfactant produced by halophilic Ochrobactrum sp. strain BS-206 (MTCC 5720): Purification,characterization and its biological evaluation

A new bioactive molecule characterized as 4-dimethylaminobenzaldehyde (designated as Ochrosin) was isolated from a halophilic Ochrobactrum sp. strain BS-206 (MTCC 5720). Ochrosin exhibited good antimicrobial activity against both Gram-positive and Gram-negative bacteria and different Candida strains with minimum inhibitory concentration (MIC) values ranging from 4.68 to 150 μg mL⁻¹. It also exhibited anti-adhesive activity against various bacterial pathogens. Ochrosin caused an increase in the reactive oxygen species (ROS) levels to 32.4% and 28% and increased the NAD⁺/NADH ratio by 2.61 and 2.26 in S. aureus and E. coli, respectively. Ochrosin appears to interfere with ergosterol biosynthetic pathway in different Candida strains as it reduced the ergosterol content. Ochrosin showed insecticidal activity against three major stored-product grain pests like Tribolium castaneum, Callosobruchus chinensis and Sitophilus oryzae with LC₅₀ values of 7.3, 8.9 and 7.6 μg cc⁻¹, respectively. The anti-feedant index (ED₅₀) values observed were 1.07 and 1.35 μg cm⁻² of leaf area against Achaea janata and Spodoptera litura, respectively. This is the first report on Ochrosin, a multifunctional biosurfactant, produced by Ochrobactrum sp. BS-206 exhibiting promising antimicrobial, anti-adhesive, anti-feedant and insecticidal activities.     

Purification, characterization, and sequencing of antimicrobial peptides, Cy-AMP1, Cy-AMP2, and Cy-AMP3, from the Cycad (Cycas revoluta) seeds

Novel antimicrobial peptides (AMP), designated Cy-AMP1, Cy-AMP2, and Cy-AMP3, were purified from seeds of the cycad (Cycas revoluta) by a CM cellulofine column, ion-exchange HPLC on SP COSMOGEL, and reverse-phase HPLC. They had molecular masses of 4583.2 Da, 4568.9 Da and 9275.8 Da, respectively, by MALDI–TOF MS analysis. Half of the amino acid residues of Cy-AMP1 and Cy-AMP2 were cysteine, glycine and proline, and their sequences were similar. The sequence of Cy-AMP3 showed high homology to various lipid transfer proteins. For Cy-AMP1 and Cy-AMP2, the concentrations of peptides required for 50% inhibition (IC₅₀) of the growth of plant pathogenic fungi, Gram-positive and Gram-negative bacteria were 7.0–8.9 μg/ml. The Cy-AMP3 had weak antimicrobial activity. The structural and antimicrobial characteristics of Cy-AMP1 and Cy-AMP2 indicated that they are a novel type of antimicrobial peptide belonging to a plant defensin family.     

Antimicrobial and antioxidant activities with acute toxicity,cytotoxicity and mutagenicity of Cystoseira compressa (Esper) Gerloff & Nizamuddin from the coast of Urla (Izmir,Turkey)

The aim of the study was to evaluate the biological activities with toxic properties of the methanol, hexane, and chloroform extracts of Cystoseira compressa (Esper) Gerloff & Nizamuddin from the Coast of Urla in the Aegean Sea. The extracts of C. compressa were tested for their antimicrobial and antioxidant activities in this study. Cytotoxic and mutagenic potentials of the extracts were also evaluated using cell culture and mutagenicity assays. Hexane extract was found to have higher total flavonoid and phenolic contents than the other extracts and exerted higher antioxidant activity than other extracts. All extracts exhibited moderate antimicrobial activity against tested microorganisms (minimum inhibitory concentration ranges are 32–256 μg/mL). The results indicated that the extracts had no significant cytotoxic activity against human hepatocellular carcinoma Hep 3B cell line in all treated concentrations (5–50 μg/mL) and did not show mutagenicity in the Ames test. Lethality was not observed among mice treated with oral doses of the extracts. In conclusion, results of investigations indicate that brown alga C. compressa is a natural source of antioxidant. It has moderate antimicrobial activities with no toxicity.     

Glucosinolates,flea beetle resistance,and leaf pubescence as taxonomic characters in the genus Barbarea (Brassicaceae)

Glucosinolate content of leaves and roots, diversity in leaf pubescence, and resistance to two near-isogenic lines of the flea beetle Phyllotreta nemorum with or without an R-gene, were determined for 27 accessions of 7 Barbarea taxa, i.e. B. stricta, B. orthoceras, B. intermedia, B. verna, B. vulgaris var. vulgaris, the G-type of B. vulgaris var. arcuata and the P-type of B. vulgaris var. arcuata. Four variable glucosinolate biosynthetic characters were deduced. For (formally) homophenylalanine-derived glucosinolates: (1). Presence or absence of 2-hydroxylation, and if present, R- or S-configuration of 2-hydroxylation; (2). presence or absence of p-hydroxylation; and for tryptophan-derived glucosinolates: (3). presence or absence of N-methoxyglucobrassicin; and (4). presence or absence of 1,4-dimethoxyglucobrassicin. Three phenotypes of leaf-pubescence were observed; (1). glabrous to glabrate leaves; (2). glabrous to glabrate leaves with hairs along the edge; (3). pubescent leaves. The hairs were characterized as simple by scanning electron microscopy. Full resistance to a flea beetle line (ST) was found in B. vulgaris var. vulgaris and in the G-type of var. arcuata; partial resistance was found in B. verna and B. intermedia, while the remaining taxa were fully susceptible to the ST line. All investigated Barbarea taxa were susceptible to larvae from another line containing an R-gene, indicating a similar flea beetle resistance mechanism in the three resistant species. Most Barbarea taxa could be characterized by a particular combination of the investigated characters. The most aberrant was the P-type of B. vulgaris var. arcuata, and the taxonomic status of this type should be reconsidered.     

Bergamot natural products eradicate cancer stem cells (CSCs) by targeting mevalonate,Rho-GDI-signalling and mitochondrial metabolism

Here, we show that a 2:1 mixture of Brutieridin and Melitidin, termed “BMF”, has a statin-like properties, which blocks the action of the rate-limiting enzyme for mevalonate biosynthesis, namely HMGR (3-hydroxy-3-methylglutaryl-CoA-reductase). Moreover, our results indicate that BMF functionally inhibits several key characteristics of CSCs. More specifically, BMF effectively i) reduced ALDH activity, ii) blocked mammosphere formation and iii) inhibited the activation of CSC-associated signalling pathways (STAT1/3, Notch and Wnt/beta-catenin) targeting Rho-GDI-signalling. In addition, BMF metabolically inhibited mitochondrial respiration (OXPHOS) and fatty acid oxidation (FAO). Importantly, BMF did not show the same toxic side-effects in normal fibroblasts that were observed with statins. Lastly, we show that high expression of the mRNA species encoding HMGR is associated with poor clinical outcome in breast cancer patients, providing a potential companion diagnostic for BMF-directed personalized therapy.