Detection of Artichoke Latent Virus by an Indirect Dot-ELISA

An indirect Dot-ELISA was compared with DAS-ELISA for detecting Artichoke Latent Virus (ALV) both in purified preparations and in crude sap from “Spinoso sardo” artichoke leaves. Antigen diluted samples (1 μl) were first spotted on nitrocellulose (NC) and polyvinylidene difluoride (PVDF) membranes. After blocking, the membranes were incubated in rabbit anti-ALV IgG, then in goat anti-rabbit IgG—alkaline phosphatase conjugate, and finally exposed to substrate and examined for a coloured precipitate. The minimum detection levels for ALV by Dot-ELISA were 125 pg of purified virus and 1/2,000 dilution of virus-infected sap on NC, and 83.3 pg of purified virus and 1/4,000 dilution of virus-infected sap on PVDF, as compared with 50 ng of purified virus and 1/1,000 dilution of virus-infected sap detectable by DAS-ELISA. This indirect Dot-ELISA proved to be more sensitive and more economical than DAS-ELISA, and can be completed in as little as 5—6 hours.     

Artichoke Italian latent virus causes artichoke patchy chlorotic stunting disease

Artichoke patchy chlorotic stunting (APCS) is the most serious disease affecting artichoke in Greece. It is widespread in Argolis, the main artichoke centre in Greece, where the local thornless artichoke, cv. “Argos”, is cultivated. The disease was first noticed in 1982, but to growers it was known since earlier times. Data collected during 1980–1990 revealed its wide distribution in the area, its patchy dispersal in fields, and its annual radial increase of the patches during the years, as well as a centripetal symptomatological severity gradient within each patch. These observations indicated a soil-borne nature for the disease. Field surveys for several viruses indicated a correlation of APCS with artichoke Italian latent nepovirus (AILV), a soil-borne virus known to occur in such patches and transmitted by the vector nematode Longidorus fasciatus Roca et Lamberti. In experiments fulfilling Koch's postulates, it was possible to reproduce the symptoms of APCS, demonstrating that AILV is a cause of the disease, if not the only one. Field surveys also revealed the ubiquitous occurrence of artichoke mottled crinkle virus (AMCV), independently of any particular symptoms. In the same survey, broad bean wilt virus (BBWV), also, was recovered from artichoke in Greece for the first time.     

Partial Characterization of Artichoke Virus M

A virus with filamentous particles 697 nm in length was isolated from artichoke plants in Southern Italy and identified as a new possible member of Carlavirus group, for which the name artichoke virus M (AVM) is suggested. AVM could not be transmitted by sap inoculation to herbaceous hosts and was always present in artichoke in mixed infections with other viruses. Virus particles had a buoyant density in CsCl of 1.31 g × cm^?3 and contained a single species of nucleic acid with an apparent size of 7.5 Kb and a single coat protein species with a mol. wt of 31,000. The virus was distantly related serologically to carnation latent and poplar mosaic carlaviruses but not to other members of the group including the recently described artichoke latent S carlavirus. Cytological alterations consisted of complex cytoplasmic inclusions composed of deranged organelles, lipid droplets and accumulations of membranes.     

Constancy of rDNA Content during Dedifferentiation of Carrot and Jerusalem Artichoke Explants

When carrot explants were cultured with phytohormones, DNA synthesistook place synchronously in the explants and a satellite DNAwith a heavier density in CsCl than the bulk DNA replicatedin the earliest phase of the first replication period. The earlyreplicating carrot satellite consisted of a component havingan identical density to carrot rDNA and another component havinga density between the p-value of carrot rDNA and that of thebulk DNA. DNA-rRNA hybridization was used to explore the possibilitythat this early replication of the satellites leads to amplificationof rDNA in the explant cells, in which massive ribosome synthesisis known to occur. The results showed that there was neitheramplification nor underreplication of rRNA genes during callusformation and its growth. Experiments with explants of Jerusalem artichoke tuber, whichare well known as a synchronous replication system, showed thata component slightly heavier than the bulk DNA was synthesizedat the early phases of the first replication period. However,the density of this early replicating satellite differed fromthat of artichoke rDNA. DNA-rRNA hybridization experiments againshowed no gross changes of rDNA content during dedifferentiationof this plant system. (Received September 30, 1981; Accepted January 5, 1982)     

Artichoke latent virus: characterisation, ultrastructure and geographical distribution

An isolate of artichoke latent virus (ALV-I) obtained from a symptomless artichoke plant in Southern Italy was characterised and compared with ALV isolates from other countries. ALV occurs in California and throughout the western part of the Mediterranean basin but of Mediterranean countries east of Italy, it was found only in Israel and Turkey. ALV-I was readily transmissible by inoculation of sap to a moderate range of hosts, was transmitted in a non-persistent manner by Aphis fabae, Brachicaudus cardui and Myzus persicae, but was not seed transmitted. The virus has flexuous rod-shaped particles measuring c. 12 nm × 746 nm with a sedimentation coefficient of 145 S and a buoyant density of 1·31 g/cm³. The particles contain single stranded RNA with a mol. wt of 3 × 10⁶ and protein composed of a single polypeptide species with a mol. wt of 33 000. Cylindrical cytoplasmic inclusions consisting of pinwheels and laminated aggregates were present in cells of naturally and artificially infected plants. ALV isolates from different geographical origin were indistinguishable from ALV-I biologically, morphologically, serologically and ultrastructurally. These properties place ALV in the Potyvirus group, but it was serologically unrelated to 12 other potyviruses 10 of which occur commonly in Italy.     

Localization of the Enzymes of Fructan Metabolism in Vacuoles Isolated by a Mechanical Method from Tubers of Jerusalem Artichoke (Helianthus tuberosus L.)

Vacuoles isolated by a mechanical slicing method from developing tubers of Jerusalem artichoke (Helianthus tuberosus L.) contain activities of the two principal enzymes responsible for fructan synthesis: sucrose-sucrose fructosyl transferase and fructan-fructan fructosyl transferase. Both enzymes are associated with the vacuolar sap and not with the tonoplast. In vacuoles isolated from dormant tubers, the fructan-fructan fructosyl transferase activity remains in the vacuolar sap but the fructan exohydrolase activity is associated with the tonoplast. Fructan is hydrolysed by these vacuoles to fructose, which can be exported to the suspending medium. The localization of the enzymes of fructan metabolism in the vacuole has implications for the maintenance of fructan polymerisation.     

Molecular characterization and systemic induction of single-chain ribosome-inactivating proteins (RIPs) in sugar beet (Beta vulgaris) leaves

Sugar beet (Beta vulgaris L.) leaves contain virus-inducible type 1 (single chain) ribosome-inactivating proteins that have been named beetins. The structural and functional characterization, the cellular location, and the potential role of beetins as antiviral agents are reported here. Beetins are formed of a single polypeptide chain with a varying degree of glycosylation and strongly inhibited in vitro protein synthesis in rabbit reticulocyte lysates (IC50=1.15 ng ml(-1)) and a Vicia sativa L. cell-free system (IC50=68 ng ml(-1)) through the single depurination of the large rRNA. Beetins trigger the multidepurination of tobacco mosaic virus (TMV) genomic RNA which underwent extensive degradation upon treatment with acid aniline. Beetins are extracellular proteins that were recovered from the apoplastic fluid. Induction of sugar beet RIPs with either H2O2 or artichoke mottled crinkle virus (AMCV) was observed in leaves distant from the site of application of such elicitors. The external application of purified beetin to sugar leaves prevented infection by AMCV which supports the preliminary hypothesis that beetins could be involved in plant systemic acquired resistance subjected to induction by phytopathogens.     

Preliminary Studies on Black Spot of Globe Artichoke

Studies were conducted to determine the cause of an apparently new disorder of globe artichoke ( Cynara scotymus L.) characterised by a localised black necrosis in the receptacle of the flower buds. The effects of single and mixed infections by artichoke latent potyvirus (ALV) and broad bean wilt virus – French artichoke (BBWV-FA) in buds with necrosis of three globe artichoke cultivars were studied. Virus-free plants developed diseased buds irrespective of whether the plants were 1 or 2 years old, but the presence of ALV and/or BBWV-FA significantly increased black spot occurrence on 2-year-old plants. Virus effects were dependent on cultivar, cv. Capitan being less susceptible to virus infection than cvs Camus de Bretagne and Castel. The head size of the globe artichoke was found to be related to the rate of necrosis, with a higher incidence for terminal buds.
ALV and BBWV-FA did not cause the disorder but favour its development probably by weakening plants through increased leaf transpiration. The results are discussed in relation to a possible physiological disorder exacerbated by the presence of ALV and/or BBWV-FA.     

Phytochemical Compounds from the Crop Byproducts of Tunisian Globe Artichoke Cultivars

The phytochemical composition in two Tunisian globe artichoke cultivars (bracts, leaves, and floral stems) was evaluated in the plant byproducts. The results indicated that the bracts contain the highest levels of total phenols, o‐diphenols, and flavonoids, whereas tannins seem to be more abundant in the leaves. Bracts from the ‘Violet d'Hyères’ cultivar possessed more total phenols (160.8 mg/g DW), flavonoids (64.9 mg/g DW), and anthocyanins (15.3 μg/g DW) than the ‘Blanc d'Oran’ bracts (134.5 mg/g DW, 51.2 mg/g DW, and 8.3 μg/g DW, resp.). Sixty‐four volatile compounds were identified in the headspace of globe artichoke material, particularly in the bracts. The volatile profile showed that sesquiterpene hydrocarbons and non‐terpene derivatives were the main volatiles emitted by the bracts in both cultivars. These results suggest that globe artichoke byproducts might represent a potential source of natural compounds, which could be used as nutraceuticals or as ingredients in the design of functional foods.     

Effects of Artichoke Latent Virus Infection on the Production of Artichoke Heads

Virus-free and artichoke latent virus (ALV) infected plants of ‘Brindisino’ artichoke obtained by in vitro propagation, were studied over a period of three years to evaluate the effect of ALV infection on artichoke field performance and to determine the infection rate of healthy plants. ALV infection caused qualitative and quantitative changes ‘Brindisino’ artichoke such as leaf and bract discoloration, opening of head apex, delay of first harvest, shortening of head stalk, reduction of head width and a dramatic decrease of yield. Due to the high infection rate of healthy plants during the trial period, the differences in the production of heads between the two groups of plants decreased in the last year of experiment.     

Artichoke juice improves endothelial function in hyperlipemia

Artichoke extracts have been shown to produce various pharmacological effects, such as the inhibition of cholesterol biosynthesis and of LDL oxidation. Endothelial dysfunction represents the first stage of atherosclerotic disease; it is usually evaluated in humans by a noninvasive ultrasound method as brachial flow-mediated vasodilation (FMV) and by the determination of several humoral markers such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin. Aim of the study was to investigate the effects of dietary supplementation with artichoke juice on brachial FMV of hyperlipemics. We studied 18 moderately hyperlipemic patients (LDL cholesterol > 130 <200 mg/dl and/or triglycerides >150 <250 mg/dl) of both genders and 10 hyperlipemic patients, matched for age, sex and lipid parameters. All subjects were under isocaloric hypolipidic diet. A basal determination of serum lipids, soluble VCAM-1, ICAM-1, E-selectin and brachial FMV was performed. Thereafter patients were given 20 ml/die of frozen artichoke juice. The same parameters were repeated after 6 weeks. After artichoke treatment there was an increase of triglycerides (156 +/- 54 vs 165 +/- 76 mg/dL, p <0.05) and a reduction of total cholesterol (261 +/- 37 vs 244 +/- 38 mg/dL, p <0.05) and LDL cholesterol (174 +/- 31 vs 160 +/- 34 mg/dL, p <0.05). Controls showed a significant decrease in total and LDL cholesterol (respectively: 267 +/- 22 vs 249 +/- 20 mg/dL and 180 +/- 24 vs 164 +/- 23 mg/dL, both p <0.001). After artichoke there was a decrease in VCAM-1(1633 +/- 1293 vs 1139 +/- 883 ng/mL, p <0.05) and ICAM-1(477 +/- 123 vs 397 +/- 102 ng/mL, p <0.05), brachial FMV increased (3.3 +/- 2.7 vs 4.5 +/- 2.4%, p <0.01), while controls did not exhibit significant changes in VCAM-1, ICAM-1, E-selectin and brachial FMV. Univariate analysis showed that, in artichoke patients, changes of VCAM-1 and ICAM-1 were significantly related to changes in brachial FMV (respectively: r=-0.66 and r=-0.62; both p <0.05). In conclusion, artichoke dietary supplementation seems to positively modulate endothelial function in hypercholesterolemia.     

Black Spot of Globe Artichoke: a Calcium-deficiency Disorder

Experiments were performed with field-grown artichoke ( Cynara scolymus L.) cv. Capitan to determine whether the black spot disorder was associated with calcium deficiency in receptacles. Ageing of the plants and size of heads contributed to lower Ca levels of receptacles. Receptacles with lower amounts of Ca were more affected by the disorder. Globe artichoke infection by artichoke latent virus (ALV) and/or broad bean wilt virus strain french artichoke (BBWV-FA) resulted in decreases in both the relative water content (RWC) of leaves and the Ca content of receptacles, and in increased black spot incidence. In addition, a wind-screen and an anti-trans-pirant spray (composed of a wax emulsion and a spreader/sticker surfactant) increased the RWC of leaves and bracts and the Ca content of receptacles, and also significantly reduced the incidence of necrosed buds.
These data support the view that Ca deficiency is involved in the occurrence of black spot disorder.     

Structure-based design and experimental engineering of a plant virus nanoparticle for the presentation of immunogenic epitopes and as a drug carrier

Biomaterials research for the discovery of new generation nanoparticles is one of the most active areas of nanotechnoloy. In the search of nature-made nanometer-sized objects, plant virus particles appear as symmetrically defined entities that can be formed by protein self-assembly. In particular, in the field of plant virology, there is plenty of literature available describing the exploitation of plant viral cages to produce safe vaccine vehicles and nanoparticles for drug delivery. In this context, we have investigated on the use of the artichoke mottled crinkle virus (AMCV) capsid both as a carrier of immunogenic epitopes and for the delivery of anticancer molecules. A dual approach that combines both in silico tools and experimental virology was applied for the rational design of immunologically active chimeric virus-like particles (VLPs) carrying immunogenic peptides. The atomic structures of wild type (wt) and chimeric VLPs were obtained by homology modeling. The effects of insertion of the HIV-1 2F5 neutralizing epitope on the structural stability of chimeric VLPs were predicted and assessed by detailed inspection of the nanoparticle intersubunit interactions at atomic level. Wt and chimeric VLPs, exposing on their surface the 2F5 epitope, were successfully produced in plants. In addition, we demonstrated that AMCV capsids could also function as drug delivery vehicles able to load the chemotherapeutic drug doxorubicin. To our knowledge, this is the first systematic predictive and empirical research addressing the question of how this icosahedral virus can be used for the production of both VLPs and viral nanoparticles for biomedical applications.     

Proximate Composition,Minerals and Antioxidant Activity of Artichoke Leaf Extracts

Biological Trace Element Research - In this study, leaf extracts from the Green Globe cultivar of artichoke (Cynara scolymus L.), a herbaceous plant of the Asteraceae family, were analyzed to...     

Artichoke and Cynar liqueur: Two (not quite) entangled proteomes

Combinatorial peptide ligand libraries (CPLLs) have been adopted to investigate the proteome of artichoke extracts, of a home-made alcoholic infusion and of the Italian Cynar liqueur. The aim of study was not only to perform the deepest investigation so far of the artichoke proteome but also to assess the genuineness of the commercial aperitif via a three-pronged attack. First, different extraction techniques have been used for the characterization of the artichoke's proteome, secondly a home-made infusion has been analyzed and finally the proteome of the commercial drink was checked. The artichoke proteome has been evaluated via prior capture with CPLLs at four different pH (2.2, 4.0, 7.2 and 9.3) values. Via mass spectrometry analysis of the recovered fractions, after elution of the captured populations in 4% boiling SDS, we could identify a total of 876 unique gene products in the artichoke extracts, 18 in the home-made infusion and no proteins at all in the Italian Cynar liqueur, casting severe doubts on the procedure stated by the manufacturer (that should be made by an infusion of artichoke leaves plus thirteen different herbs). This could be the starting point for investigating the genuineness and natural origin of commercial drinks in order to protect consumers from adulterated products.     

cDNA cloning of artichoke mottled crinkle virus RNA and localization and sequencing of the coat protein gene

We report the cDNA cloning of the genomic RNA of artichoke mottled crinkle virus (AMCV), which is a member of Tombusvirus group. AMCV has a monopartite positive sense RNA genome, which is not polyadenylated at the 3 end. The genome size is 4.8 kb.We have localized and sequenced the open reading frame (ORF) encoding the coat protein. Unlike most monopartite positive-strand RNA plant viruses, the ORF is not located near the 3 end, but like other members of the Tombusvirus group, CyRSV (cymbidium ringspot virus), TBSV-cherry (tomato bushy stunt virus cherry strain) and CNV (cucumber necrosis virus) it starts ca. 2.7 kb downstream of the 5 end and stops ca. 1 kb upstream of the 3 end. This ORF predicts a polypeptide chain of 387 amino acids.Comparison of the coat proteins of AMCV, TBSV-BS3, TBSV-cherry and CNV confirms that, within the Tombusvirus group, there exists a high degree of similarity among coat proteins but that this similarity is not uniformly distributed among domains. In particular, the N-terminal region, thought to make contact with the phosphate groups of the viral RNA, and the C-terminal region, considered the most immunogenic portion of the capsid, are found to be the least homologous.     

圆红冬孢酵母发酵菊芋块茎产油脂的研究

研究了圆红冬孢酵母Y4发酵菊芋块茎,菊芋品种及其处理方法对发酵产油的影响。结果表明,菊芋浸提汁、酸水解液或菊芋浆均可直接被圆红冬孢酵母Y4利用,发酵积累油脂,但白皮菊芋比紫皮菊芋更有利于油脂发酵。发酵菊芋浸提汁或酸水解液时,无需添加外源营养物,干菌体油脂含量可达到40%（w/w）;发酵菊芋浆时,白皮菊芋转化率达到12.1 g油/100 g去皮干菊芋。菊芋油脂发酵产品主要以16碳和18碳系脂肪酸为主,与常规植物油的脂肪酸组成相似,可作为制备生物柴油的新型替代原料。