Blackfoot Disease Research Articles

The efficacy of some endophytic fungi against primary grapevine black foot disease pathogens

ABSTRACT Black foot disease (BFD), primarily attributed to taxa within the genera Dactylonectria and Ilyonectria, is a significant problem that causes serious damage worldwide in many grape and wine regions. This threat could especially be destructive in nurseries and early-stage vineyards, where it induces a decline in growth along with drying, leading to a reduction in the quality and lifespan of the grapevines. This research mainly focused on assessing the biocontrol capabilities of endophytic isolates derived from grapevine saplings, specifically Acremonium sclerotigenum and Clonostachys rosea. The study aimed to assess their effectiveness against the major pathogens responsible for BFD, including Dactylonectria macrodidyma, D. torresensis, and I. liriodendri, under laboratory and in vivo conditions. In the conducted paired culture assays, Trichoderma harzianum KRL-AG2 was employed for comparative purposes. On the 28th day of antagonistic tests, the inhibition response of A. sclerotigenum (≥94%) and C. rosea (>90%) isolates against the three species of BFD, D. macrodidyma, D. torresensis, and I. liriodendri, reached the maximum inhibition rate. Based on the in vivo analysis conducted with 1103 P rootstocks, T. harzianum, A. sclerotigenum, and C. rosea isolates significantly reduced the disease severity and supplied notable positive effects on plant growth parameters, including root dry weight, root length, and shoot dry weight. These results suggest that these biocontrol agents have potential for the biological management of BFD.

Isolation and Reproductive Structures Induction of Fungal Pathogens Associated with Xylem and Wood Necrosis in Grapevine.

Grapevine (Vitis vinifera L.) trunk diseases (GTDs) are considered a disease complex including five diseases: esca, Petri disease, black-foot disease, Botryosphaeria dieback, and Eutypa dieback. The main symptom is a general decline in affected plants, which show xylem necrosis and discoloration or sectorial necrosis in the wood. Their diagnosis is tedious due to four main reasons: (i) the wide diversity of internal symptoms that we can find; (ii) the great diversity of fungi that are associated with them; (iii) the high frequency of co-infections in the same plant; and (iv) the different behavior that the fungal species associated with GTDs show in vitro. Here, we describe a detailed protocol to isolate the different fungal trunk pathogens associated with GTDs as well as methods to induce sporulation and formation of fruiting bodies (pycnidia) to make easier their morphological characterization.

Assessment of the tube-well water quality: A micro-level case study from Lower Gangetic Plain (LGP) in North 24 Parganas district, West Bengal, India

The purpose of this study is to investigate the quality of tubewell water (TW) in Barasat-I (Community Development Block) under North 24 Parganas District of Lower Gangetic Plain (LGP), West Bengal, India with respect to suitability for drinking purpose. This is the first micro-level ground water related study in this region. In total twenty (20) groundwater (GW) samples from tube-wells at different locations of nine (09) Gram Panchayats (GP) were collected and analyzed. The results have been compared with the Indian standard (IS) for drinking water based on eight parameters, such as pH, total dissolved solids (TDS), total suspended solid (TSS), conductivity, total alkalinity (TA), total hardness (TH), chloride (Cl), and arsenic (As). Moreover, TDS (50%) and Total Hardness (TH) (90%) were found to be above the desirable limit. However, pH, Chloride, has been found to be within the permissible limit. This micro-level study revealed that high contamination with arsenic of GW has been identified on the middle to eastern side of Barasat-I. As is found to be above acceptable limit at 70% sampling points. Therefore, rural people of the eastern side of the Barasat-I are prone to a higher risk of black-foot disease due to higher level of As. Overall, the groundwater in this block is not suitable and fit for direct drinking. It needs treatment to minimize pollution or contamination, where regular monitoring and analysis is recommended to determine the extent of contamination in the other parts of LGP. The findings of this study will be beneficial to manage and control ground water vulnerability in micro-level for water scientists, policy makers, and researchers as well in sustainable way and must be achieved by 2030.

Removal of toxic arsenic(iii) from an old endemic black-foot disease groundwater by oxidative electrosorption

Environmental context Naturally occurring arsenic was the likely cause of endemic black foot disease in groundwaters in Taiwan, and levels still exceed Taiwan EPA water quality standards. A method for the clean-up of these groundwaters that is both feasible and environmentally friendly is urgently needed. Oxidation of As(III) as H3AsO3 to the less toxic As(V)− and removal of As in groundwater was performed quantitatively by electrosorption using materials derived from agricultural wastes; this shows that this method has the potential to be a novel, green remediation method. Rationale Naturally occurring arsenic in the groundwater caused black-foot disease (BFD) in the 1950s on the southwest seashore of Taiwan. Recently, we found that the concentration of arsenic in groundwater taken from currently sealed wells in areas previously affected by BFD remained higher than the Taiwan (EPA) water quality standard. Although clean tap water is available in that area, removal of arsenic from the groundwater is of great importance to expand possible utilisation. Methodology Removal of arsenic from two old endemic BFD groundwaters with activated carbon (AC) electrodes recycled from agricultural wastes by electrosorption using capacitive deionisation (CDI) processes was studied. A better understanding of arsenic electrochemistry involved in electrosorption was investigated by in situ X-ray absorption near-edge structure spectroscopy. Results Arsenic removal efficiencies (61–93%) remained high across concentrations (5 and 196 mg/L). A high oxidation rate constant (0.93 h−1) for As(III)0 to As(V)− was found, allowing the electrosorption of As(V)− onto the meso- and micro-pores of the AC CDI electrodes with rate constants of 0.021 and 0.0013 h−1, respectively. Removal of arsenic from contaminated groundwater for drinking water was achieved with six CDI reactors in series. Moreover, in the presence of other ions (such as Na+, Mg2+ and Ca2+), 60–73% of As(III)0 and As(V)− ions were removed from the groundwaters by electrosorption. Discussion We have developed an engineering-feasible method for converting As(III)0 to less toxic As(V)−, enabling its removal by electrosorption, which demonstrates the feasibility for green remediation of BFD waters as well as other arsenic-contaminated groundwaters.

Impact Of Chronic Arsenic Toxicity on Human Health- A Review

The levels of heavy metals in ground water continue to be higher than those considered acceptable by regulatory agencies in different countries across the world. One of the most important public health problems in the world is chronic arsenic poisoning, or arsenicosis, caused by drinking water that has been poisoned with arsenic. Arsenic poisoning over time has been related to a number of cancers of the skin, oral cavity, urinary bladder, kidney, and lung in addition to bone marrow depression, Blackfoot disease, cardiovascular disease, diabetes, hypertension, and a host of other ailments. In addition, arsenic causes DNA damage that has genotoxic effects. Around the world, 137 million people in 70 different nations depend on drinking water that has been drawn from severely contaminated groundwater. The two nations that have been affected the most so far are Bangladesh and West Bengal, India. The drinking water of 26 million people in nine districts of West Bengal contains levels of arsenic that are significantly higher than the WHO-acceptable limit of 10 g/l. The review focuses on the impact of chronic arsenic toxicity on public health worldwide.

Grapevine nursery propagation material as source of fungal trunk disease pathogens in Uruguay.

Grapevine fungal trunk diseases (GTDs) have become a serious problem for grapevines worldwide. Nursery vines infected during the propagation process are considered one of the main ways of dissemination of GTD pathogens. In this study, we examined the status of GTDs in grapevine planting material, from rootstocks and scion mother cuttings to grafted rooted vines ready to plant, according to the local nursery propagation process. During 2018-2019, internal symptoms of GTDs were examined in 2400 propagation materials and fungal isolations were carried out from a subsample of 1026 selected materials. Our results revealed that nursery grapevine plants produced in Uruguay have a high incidence of GTDs, regardless of the scion/rootstock combination. Typical brown to black streaks and sectorial wood necrosis were observed in materials on all propagation stages, with a markedly increasing incidence throughout the nursery process, reaching almost 100% in grafted rooted vines ready to plant. Botryosphaeria dieback, Petri disease and black-foot disease were the main GTDs found. The results showed that Botryosphaeria dieback and Petri disease pathogens infect materials from the early stages of the process, with a marked increase towards the end of the plant production process, whereas black-foot disease pathogens were found exclusively in vines ready to plant. Diaporthe dieback pathogens were also detected in materials in all stages but in a low proportion (less than 10% of infected material). Based on single locus analysis, the 180 isolates selected were placed into eight genera and 89% identified within 22 fungal species associated with GTDs, with Phaeoacremonium oleae and Diaporthe terebinthifolii as new records on grapevine worldwide. Our results have concluded that locally produced vines are one of the main ways of dissemination of GTD pathogens and showed that a nursery sanitation programme is required to reduce the incidence of these diseases.

First Report of Dactylonectria alcacerensis, Dactylonectria macrodidyma, and Ilyonectria liriodendri Associated with Black Foot Disease of Grapevine in Argentina.

Black-foot is a fungal disease that affects young vines and planting material in the countries where grapevines are cultivated. During the 2018 grape-growing season, symptoms of reduced vigor, short internodes, leaf chlorosis, root rot and necrosis in the base of plants were observed in vines between 2 to 10 years old from 400 ha of vineyards of Mendoza and Salta regions. A total of 30% of the vineyards of cultivars Malbec, Cabernet Sauvignon and Aspirant Bouchet, and rootstocks 101-14 Millardet et de Grasset and 1103 Paulsen, had vines with disease symptoms. Vines had 15% disease incidence and 30% disease severity. These symptoms have been described as characteristic of black-foot, caused by "Cylindrocarpon"-like asexual morph fungi. Isolations were made from roots and basal part of 30 symptomatic plants. Fragments of advanced necrotic tissue were washed with running water, surface sterilized with 70% alcohol for 20 seconds, 2% NaOCl solution for 4 minutes and rinsed in sterile distilled water twice. These fragments were placed onto Potato Dextrose Agar (PDA) and incubated at 25°C in the dark for 10 days to isolate fungal pathogens. A total of 50 colonies resembling black-foot disease pathogens were subcultured onto fresh PDA in order to obtain single spore cultures. The isolates developed buff to cinnamon and dark brown, and felty mycelium. Colonies subcultured in synthetic nutrient agar (SNA) produced hyaline, cylindrical, straight and/or slightly curved with one to three septate (35.6 × 5.3 µm) macroconidia and abundant, hyaline, ellipsoidal and zero to one septate (12.5 × 6.0 µm) microconidia. Cultures and conidia morphological characteristics were similar to those of Ilyonectria or Dactylonectria genera (Cabral et al. 2012a; Lombard et al. 2014). DNA sequence analysis of the partial histone H3 gene was obtained for isolates INTA SC1 (I. liriodendri), INTA LC2 (D. alcacerensis) and INTA LC1 (D. macrodidyma) and deposited in GenBank (accession nos. OK338901, OK338900 and OK338899). The BLAST search was conducted against type specimens. Sequences showed high similarity (99% to 100%) to the sequences of Ilyonectria liriodendri (Halleen, Rego & Crous) Chaverri & Salgado (GenBank accession no. JF735509), Dactylonectria alcacerensis (A. Cabral, Oliveira & Crous) L. Lombard & Crous (GenBank accession no. JF735630) and Dactylonectria macrodidyma (Halleen, Schroers & Crous) L. Lombard & Crous (GenBank accession no. JF735647). Pathogenicity tests were conducted under greenhouse conditions on 1-year-old rooted canes cv Malbec using the three isolates. Ten rooted cuttings with pruned roots were immersed in a suspension of 106 conidia ml-1 of each isolate for 60 min (Cabral et al. 2012b) while control cuttings were immersed in sterile distilled water. Immediately they were planted in pots and kept in a greenhouse at a temperature between 25 to 30°C. Symptoms developed on all plants 4 months after inoculation and consisted in necrotic lesions of roots and in the base of the canes, with a reduction in root biomass. Plants did not develop aerial symptoms. All fungi were re-isolated only from necrotic lesions of root and base of inoculated canes, fulfilling Koch's postulates. No symptoms were observed on the control plants. To our knowledge, this is the first report of the species I. liriodendri, D. alcacerensis and D. macrodidyma associated with black-foot disease of grapevine in Argentina. Black-foot disease has a negative effect on the viability of planting material and young vines, and this report will assist with monitoring distribution of the disease as well as developing management recommendations to nurseries and grape growers in Argentina.

Mechanisms of Arsenic Exposure-Induced Hypertension and Atherosclerosis: an Updated Overview.

Arsenic is an abundant element in the earth's crust. In the environment and within the human body, this toxic element can be found in both organic and inorganic forms. Chronic exposure to arsenic can predispose humans to cardiovascular diseases including hypertension, stroke, atherosclerosis, and blackfoot disease. Oxidative damage induced by reactive oxygen species is a major player in arsenic-induced toxicity, and it can affect genes expression, inflammatory responses, and/or nitric oxide homeostasis. Exposure to arsenic in drinking water can lead to vascular endothelial dysfunction which is reflected by an imbalance between vascular relaxation and contraction. Arsenic has been shown to inactivate endothelial nitric oxide synthase leading to a reduction of the generation and bioavailability of nitric oxide. Ultimately, these effects increase the risk of vascular diseases such as hypertension and atherosclerosis. The present article reviews how arsenic exposure contributes to hypertension and atherosclerosis development.

Campylocarpon fasciculare (Nectriaceae, Sordariomycetes); Novel Emergence of Black-Foot Causing Pathogen on Young Grapevines in China.

The black-foot disease of grapevine is one of the most destructive diseases in viticulture and it is caused by a complex of soil-borne fungi. This study aimed to identify the species associated with black-foot disease in young grapevines in vineyards of China. Fungal isolates were identified as Campylocarpon fasciculare, based on both morphological and multi-locus phylogenetic analysis of ITS, tef1–α and ß-tubulin sequence data. For the first time in China, we report Campylocarpon fasciculare associated with symptomatic young grapevines. Koch’s postulates were performed on Vitis vinifera cv. Summer Black (SB) in a greenhouse and to confirm the pathogenicity on grapevines. This work improves the knowledge of black-foot disease in Chinese vineyards and will be helpful to growers in their decisions regarding vinicultural practices, planting and disease management.

Incidence and survival variations of upper tract urothelial cancer in Taiwan (2001-2010).

ObjectivesTo assess temporal patterns and regional differences in the incidence rate, and factors associated with survival of urinary tract urothelial carcinoma.MethodsThe medical records of 8830 patients with new diagnoses of urinary tract urothelial carcinoma in the years 2001–2010 were retrieved from Taiwan National databases. Temporal trends, regional disparity and related survival factors were evaluated using the Cochran–Armitage trend test, local Moran’s I statistic and log‐rank test, respectively.ResultsThe annual urinary tract urothelial carcinoma incidence rates (standardized by age) were steady at approximately 3.14–3.41 per 100 000 person‐years. Notably, women had a significantly higher annual urinary tract urothelial carcinoma incidence than men in most of the years studied (range of female‐to‐male annual standardized rate ratio: 2.08–3.25), and diabetes prevalence in urinary tract urothelial carcinoma increased significantly from 12.3% to 23.4% per year over the 10 years. High urinary tract urothelial carcinoma incidence cluster areas other than the latest endemic area of “blackfoot disease” were newly identified by local Moran’s I statistic (P < 0.05). Furthermore, older age, male sex, end‐stage kidney disease and more advanced tumor grade were associated with lower 5‐year overall survival probabilities in the 2001–2015 cohort.ConclusionsThe incidence and survival of urinary tract urothelial carcinoma over the decade 2001–2010 were different according to population and regional features. Various urinary tract urothelial carcinoma screening, prevention, treatment and care plans should be developed depending on age, sex, comorbidity and area of residence.

The relative susceptibility of grapevine rootstocks to black foot disease is dependent on inoculum pressure

Black foot disease of grapevines is a major economic issue for the viticulture industry worldwide. The disease is mainly associated with a complex of pathogen species within the genera Dactylonectria and Ilyonectria. The susceptibility of six grapevine rootstock cultivars to black foot disease under field conditions was assessed. Callused rootstocks of 101-14, 5C, 420A, Riparia Gloire, Schwarzmann and 3309C were planted into soil containing low natural pathogen populations or inoculated with isolates representing the species diversity in New Zealand. Disease incidence, disease severity and dry weight accumulation were assessed after 8 months of growth. Root and shoot dry weights were not significantly affected by inoculation treatment, but differed among rootstock cultivars, with cultivar 420A having the lowest root and shoot dry weight, cultivar 3309C having the largest shoot dry weight and cultivar 5C the largest root dry weight. The relative susceptibility of rootstocks differed significantly depending on whether they were grown under low natural inoculum pressure or a higher pressure in artificially inoculated soil. Schwarzmann and Riparia Gloire rootstock cultivars were the least susceptible under natural low inoculum pressure, but were the most susceptible in inoculated soil. In contrast, 5C was one of the most susceptible under low inoculum levels but was the least susceptible under high pathogen pressure. The result of the study indicate that black foot pathogen inoculum levels in soil affect the relative susceptibility of grapevine rootstocks to infection, and may have implications for the selection of rootstocks for planting.

Specifically designed magnetic biochar from waste wood for arsenic removal

Arsenic is a carcinogenic substance, with many cases of poisoning related to arsenic pollution in groundwater. In Taiwan arsenic in groundwater caused the notorious Blackfoot disease. Methods for arsenic removal from water include precipitation, membrane processes, ion exchange, and adsorption, but these processing technologies suffer from high investment costs and complex operations. The traditional adsorption method cannot be used for arsenic removal due to its high operating costs, difficulties in recovery, and low adsorption capacity. To address these issues, this study designed an adsorption material based on biochar for arsenic removal with higher adsorption properties and easy recovery. Biochar sources are readily available from waste wood as a cheap and environmentally friendly material. The efficiency of As (III) removal is also promoted by FeCl3 and KMnO4. The objectives of this research are to obtain optimum operation conditions by assessing the effects of different iron and manganese contents, different doses, different pH and different initial concentration. The adsorption mechanism between As (III) and biochar was studied by adsorption isotherms and the kinetic model. X-ray diffraction, energy-dispersive X-ray spectroscopy and elemental analyzer analysis results show that modified biochar has major elements of Fe and Mn. There is greater magnetism, 40 emu g− 1, in the modified biochar. The maximum adsorption efficiency of 81% and 0.72 mg g− 1 capacity occurs when the ratio of Mn, Fe and C is 4:1:1. The adsorption capacity is high under higher pH with pristine biochar and 1FeC under lower pH with 1Fe2MnC. The reaction mechanism is divided into four pathways. The first pathway is the attachment of As (III) ions into the pore of biochar via physical adsorption. In the second pathway, biochar can connect with As (III) through hydrogen bonding from the function group -OH in the biochar and the As (III) itself. In the third pathway, they can contact each other by electron force when the biochar surface is filled with a positive charge. In the fourth pathway, the compounds of manganese have strong oxidizability to oxidize As (III) to As(V). The iron ions then act as a bridge connecting the biochar and the As (III), resulting in the formation of new complex compounds.

Drought Influences Fungal Community Dynamics in the Grapevine Rhizosphere and Root Microbiome.

Plant roots support complex microbial communities that can influence nutrition, plant growth, and health. In grapevine, little is known about the impact of abiotic stresses on the belowground microbiome. In this study, we examined the drought-induced shifts in fungal composition in the root endosphere, the rhizosphere and bulk soil by internal transcribed spacer (ITS) high-throughput amplicon sequencing (HTAS). We imposed three irrigation regimes (100%, 50%, and 25% of the field capacity) to one-year old grapevine rootstock plants cv. SO4 when plants had developed 2–3 roots. Root endosphere, rhizosphere, and bulk soil samples were collected 6- and 12-months post-plantation. Drought significantly modified the overall fungal composition of all three compartments, with the root endosphere compartment showing the greatest divergence from well-watered control (100%). The overall response of the fungal microbiota associated with black-foot disease (Dactylonectria and “Cylindrocarpon” genera) and the potential biocontrol agent Trichoderma to drought stress was consistent across compartments, namely that their relative abundances were significantly higher at 50–100% than at 25% irrigation regime. We identified a significant enrichment in several fungal genera such as the arbuscular mycorrhizal fungus Funneliformis during drought at 25% watering regime within the roots. Our results reveal that drought stress, in addition to its well-characterized effects on plant physiology, also results in the restructuring of grapevine root microbial communities, and suggest the possibility that members of the altered grapevine microbiota might contribute to plant survival under extreme environmental conditions.

Spectral characterization of fungal diseases downy mildew, powdery mildew, black-foot and Petri disease on Vitis vinifera leaves

ABSTRACT Phytopathogenic diseases impact the development and yield of grapevines, resulting in economic, social and environmental losses. Sick plants have their metabolism changed, leading to alterations in their reflectance spectra. Little is known on these alterations, and a better knowledge could be used in the development of sensors able to detect diseases through fast, non-destructive techniques. This study was aimed at detecting spectral changes of grape leaves (Vitis vinifera cv. Cabernet Sauvignon), with early symptoms of downy mildew (Plasmopara viticola), powdery mildew (Uncinula necator), black-foot (Dactylonectria macrodidyma) and Petri disease (Phaeoacremonium spp.). Plants grown in pots and kept in a greenhouse were inoculated with the pathogens. In early stages of disease development, reflectance measurements were performed using a FieldSpec 3 spectroradiometer with leaf-clip attachment. The investigation began with discriminant analysis, which revealed that symptomatic plants are separated from the control ones. Reflectance spectra were, therefore, further investigated, looking for alterations on the shape of the spectra, characteristic of each disease. The disease descriptors were based on ratios between spectral features internal to a spectrum, a procedure which allowed the derivation of parameters intrinsic to each disease. A set of thresholds, defined as the ratios of reflectance at selected wavelengths, were derived for the studied diseases. For these ratios, the selected wavelengths (nm) were R443/R496, R443/R573, R443/R695, R443/R1900, R496/R573, R496/R695, R516/R1900 and R1900/R2435. The spectra from symptomatic plants present shape changes of as much as 20% with respect to healthy plants. The observed spectral changes are larger for black-foot and powdery mildew, but some wavelength ratios are also indicators of downy mildew and Petri disease. Data from wavelengths shorter than 700 nm in general carry more information than measurements at near infrared. These results are potentially useful to the development of low-cost devices to field use, providing real-time disease detection to early assessment of vineyard health status.

Evaluation of Sown Cover Crops and Spontaneous Weed Flora as a Potential Reservoir of Black-Foot Pathogens in Organic Viticulture

Simple SummaryBlack-foot is an important grapevine disease caused by a soil-borne fungal pathogens complex, which are collectively known as Cylindrocarpon-like asexual morphs. In organic viticulture, both sown and native cover crop species can act as potential reservoirs of black-foot associated fungi. In our study a wide survey of cover crops grown in organic vineyards was conducted over a diverse range of climatic zones in six different European countries to acquire information about the presence of Cylindrocarpon-like asexual morphs on their roots. Several fungal species associated with black-foot disease were found on some of the cover crops evaluated in all the countries. These results provide valuable information for a reasoned choice of cover crop species, or a species mix, that can be used in organic viticulture. This is particularly important for maximizing their benefits and reducing potential problems in vineyards.(1) Background. An extensive survey of grapevine-sown cover crops and spontaneous weed flora was conducted from 2019 to 2020 in organic vineyards in six European countries (France, Italy, Romania, Slovenia, Spain, Switzerland). Our main objective was to detect and identify the presence of Cylindrocarpon-like asexual morphs species associated with black-foot disease on their roots. (2) Methods. Fungal isolations from root fragments were performed on culture media. Cylindrocarpon-like asexual morph species were identified by analyzing the DNA sequence data of the histone H3 (his3) gene region. In all, 685 plants belonging to different botanical families and genera were analyzed. Cylindrocarpon-like asexual morphs were recovered from 68 plants (9.9% of the total) and approximately 0.97% of the plated root fragments. (3) Results. Three fungal species (Dactylonectria alcacerensis, Dactylonectria torresensis, Ilyonectria robusta) were identified. Dactylonectria torresensis was the most frequent, and was isolated from many cover crop species in all six countries. A principal component analysis with the vineyard variables showed that seasonal temperatures and organic matter soil content correlated positively with Cylindrocarpon-like asexual morphs incidence. (4) Conclusions. The presence of Cylindrocarpon-like asexual morphs on roots of cover crops suggests that they can potentially act as alternative hosts for long-term survival or to increase inoculum levels in vineyard soils.

In situ X-ray absorption spectroscopic studies of photocatalytic oxidation of As(III) to less toxic As(V) by TiO2 nanotubes.

Arsenic in groundwater caused the black-foot disease (BFD) in many countries in the 1950-1960s. It is of great importance to develop a feasible method for removal of arsenic from contaminated groundwater in BFD endemic areas. Photocatalytic oxidation of As(III) to less toxic As(V) is, therefore, of significance for preventing any arsenic-related disease that may occur. By insitu synchrotron X-ray absorption spectroscopy, the formation of As(V) is related to the expense of As(III) disappearance during photocatalysis by TiO2 nanotubes (TNTs). Under UV/Vis light irradiation, the apparent first-order rate constant for the photocatalytic oxidation of As(III) to As(V) is 0.0148 min-1. Itseems that As(III) can be oxidized with photo-excited holes while the not-recombined electrons may be scavenged with O2 in the channels of the well defined TNTs (an opening of 7 nm in diameter). In the absence of O2, on the contrary, As(III) can be reduced to As(0), to some extent. Cu(II) (CuO), as an electron acceptor, was impregnated on the TNTs surfaces in order to gain a better understanding of electron transfer during photocatalysis. It appears that As(III) can be oxidized to As(V) while Cu(II) is reduced to Cu(I) and Cu(0). The molecular-scale data are very useful in revealing the oxidation states and interconversions of arsenic during the photocatalytic reactions. This work has implications in that the toxicity of arsenic in contaminated groundwater or wastewater can be effectively decreased via solar-driven photocatalysis, which may facilitate further treatments by coagulation.

Review on double-edged sword nature of arsenic: its path of exposure, problems, detections, and possible removal techniques

ABSTRACT Chemically, Arsenic is one of the double-edged sword element distributed ubiquitously in nature. Low concentration of arsenic is used to treat leukaemia where as the high concentration of arsenic intake in human body leads to critical diseases such as skin diseases, cancer, blackfoot disease, hypertension, neurological effect, DNA damage and others. Chronic exposure may lead to coma and death. This peer review provides an overview about the distribution of arsenic species in rock, mining, and their pH dependent mobility that are found in aqueous body. The study reviews information among the various routes of arsenic exposure, their toxicity mechanisms, and a variety of total arsenic concentration detection process such as spectroscopic techniques, kit detection. The heart context of this review covers best arsenic removal techniques such as coagulation, absorption, oxidation, osmosis, electro-coagulation and others reputed techniques.

Comparative analysis of patients with upper urinary tract urothelial carcinoma in black-foot disease endemic and non-endemic area

BackgroundA high incidence of upper urinary tract urothelial carcinoma has been reported in the southwestern area of Taiwan, where arsenic water contamination was considered the main cause. However, there is no definite proof to show a correlation between arsenic water contamination and upper urinary tract urothelial carcinoma. To investigate the clinical and epidemiological features of patients with upper urinary tract urothelial carcinoma between arsenic water endemic and non-endemic areas, we analyzed patients in terms of characteristics, stratified overall survival, disease-free survival, and cancer-specific survival.MethodsThe records of a total of 1194 patients diagnosed with upper urinary tract urothelial carcinoma were retrospectively reviewed. Clinical data and current medical status were collected from the medical records. Statistical analyses were performed to determine the clinical variables and stratified survival curves between endemic and non-endemic groups.ResultsFemale predominance was revealed in both endemic and non-endemic groups (male:female ratio = 1:1.2–1.4). No statistical differences were found in histological types, staging, and tumor size between the two groups. Nonetheless, patients with characteristics of aging and having end-stage renal disease were outnumbered in the non-endemic group, while a higher prevalence of previous bladder tumors and more ureteral tumors were found in the endemic group. Adjusted stratified cumulative survival curves suggested a poorer prognosis in endemic patients, especially in disease-free survival of early stage disease.ConclusionsA higher mortality rate with more previous bladder cancer history and ureteral tumors was seen in patients with upper urinary tract urothelial carcinoma residing in the arsenic water contamination area. This may be attributed to the long-term carcinogenic effect of arsenic underground water.

Comparative Genomic Analysis of Dactylonectria torresensis Strains from Grapevine, Soil and Weed Highlights Potential Mechanisms in Pathogenicity and Endophytic Lifestyle.

The soil-borne fungus Dactylonectria torresensis is the most common causal agent of black-foot disease in Europe. However, there is a lack of understanding on how this fungus can provoke plant symptoms. In this study, we sequenced, annotated and analyzed the genomes of three isolates of D. torresensis collected from asymptomatic vine, weed and soil. Sequenced genomes were further compared to those of 27 fungal species including root and aerial pathogens, white rot degraders, indoor biodeterioration agents, saprotrophs, dark septate endophytes and mycorrhiza. Strains of D. torresensis present genomes with between 64 and 65 Mbp and with up to 18,548 predicted genes for each strain. Average Nucleotide Identity (ANI) shows that strains are different according to genome contents. Clusters of orthologous groups were compared, and clusters of genes related to necroses were particularly detected in all strains of D. torresensis (necrosis inducing peptides and proteins, and ethylene inducing peptides) as well as several genes involved in resistance against fungicides frequently used in viticulture such as copper. Interestingly, an expanded high number of genes related to carbohydrate-active enzymes were detected in each Dactylonectria strain, especially those related to glycoside hydrolases that could be involved in penetration of plant tissues or pathogenicity. An increased number of candidate genes for CAZyme classes AA9 and AA3-1 supports the ability of strains to efficiently degrade plant material. High numbers of genes of D. torresensis related to secretome and small secreted proteins were further characterized. Moreover, the presence of several gene clusters such as fujikurin-like genes was detected and were normally found in Fusarium fujikuroi, that have been linked to fungal pathogenicity. The phenotypes of the three strains investigated showed further difference in light response. We found that Dactylonectria strains have an increased number of photoreceptor encoding genes and we showed sequence alterations. Altogether, the results highlight several gene clusters present in D. torresensis strains that could be linked to endophytic lifestyle, pathogenicity, plant maceration and degradation of plant tissues as well as adaptation to soil contaminated with metals and metalloids and light response.

Field evaluation of biocontrol agents against black-foot and Petri diseases of grapevine.

Black-foot and Petri diseases are the main fungal diseases associated with young grapevine decline. Two field experiments were established to evaluate the preventive effect of two potential biocontrol agents (BCAs), that is Streptomyces sp. E1 + R4 and Pythium oligandrum Po37, and three BCA-commercial products containing Trichoderma atroviride SC1, Trichoderma koningii TK7 and Pseudomonas fluorescens + Bacillus atrophaeus on fungal infection in grafted plants and plant growth parameters. The effectiveness of some BCA in reducing the incidence and severity of both diseases was dependent on the plant part analyzed and the plant age. No single BCA application was able to control both diseases. Streptomyces sp. E1 + R4 were able to reduce significantly the infection of the most prevalent black-foot disease fungi while P. oligandrum Po37 and Trichoderma spp. were able to reduce significantly Phaeomoniella chlamydospora and Phaeoacremonium minimum (Petri disease) infection. BCA treatments had no effect on the shoot weight, and root weight was significantly lower in all BCA treatments with respect to the control. The combination of the disease-suppressive activity of two or more beneficial microbes in a biocontrol preparation is required to prevent infection by black-foot and Petri disease fungi in vineyards.