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Plant Disease Aug 2021Asiatic dayflower ( L.) is an annual herbaceous weed that is distributed throughout China. A foliar disease on Asiatic dayflowers was discovered in one farm field in...
Asiatic dayflower ( L.) is an annual herbaceous weed that is distributed throughout China. A foliar disease on Asiatic dayflowers was discovered in one farm field in Dianjiang County, Chongqing, China (N30°3´22″, E107°18´5″) in summer, 2019. The disease incidence was observed on about 10% (13/127) of the plants. Symptoms appeared as round-shaped tan lesions (2-5 mm) in diameter that occurred randomly and irregularly on the whole leaves. The centers of lesions become grayish white with reddish borders as the disease progressed. The leaves with typical symptoms were detached and wiped with 70% ethanol for surface disinfestation before isolating the causal agent. Subsequently, three pieces (3-4 mm) of tissue were taken from the margin of the leaf lesion, disinfested in 1.5% NaClO for 1 min, rinsed 3 times in sterilized distilled water, and placed onto Potato Dextrose Agar (PDA) medium containing 50 μg/ml each of kanamycin and ampicillin. A fungus was exclusively and consistently isolated from the disinfested leaf lesion sections. The colonies on PDA grew rapidly and covered the entire petri dish within 5 days at 28℃. Colonies were at first grayish white, cotton wool-like, round, with abundant aerial mycelium, and later turned black as conidia produced. The abundant conidia formed on PDA were initially yellow brown and gradually became black, oblate to ellipsoidal, smooth, single-celled, and ranged in size from 4 to 10 × 3.5 to 9 μm. They were borne on a colorless, hyaline, and inverted flask-shaped cell at the tip of each conidiophore. The morphology characteristics were consistent with those of spp. (Wang et al. 2017). Genomic DNA was extracted from one representative isolate NDJ0819. The amplification and sequencing of the gene fragments including the internal transcribed space (ITS) region of ribosomal DNA and beta-tubulin were performed using the primers ITS1/ITS4 (White et al. 1990) and Bt2a/Bt2b (Glass and Donaldson 1995), respectively. Fragments of 536 bp for ITS and 408 bp for beta-tubulin were obtained. A phylogram of the combined ITS and beta-tubulin sequences reconstructed using the maximum likelihood bootstrapping method implemented in the software MEGA version 7.0 (Kumar et al. 2016) indicated that isolate NDJ0819 clustered with . Both ITS and beta-tubulin sequences were deposited into GenBank (accession no. MT140353 and MT157509, respectively). Pathogenicity test was performed by rub-inoculating needle-wounded leaves of three 4-week-old Asiatic dayflowers with spore suspension (2.6 × 10 conidia/ml) of NDJ0819 prepared in water containing 0.05% Tween-20, and holding plants at 28℃ in the growth chamber. The pathogenicity test was repeated twice. Brown, round-shaped lesions developed on leaves inoculated with spores at 15 days post-inoculation. However, the centers of the lesion did not become grayish white, compared to those of lesions seen in naturally infected leaves. No symptoms developed on leaves inoculated with sterilized distilled water. was re-isolated from the lesions. All results described above indicated that was responsible for the leaf spot of Asiatic dayflower. To our knowledge, this is the first report of causing leaf spot on Asiatic dayflower in China. Research into the potential use of as a candidate biological agent against the weed is worth being initiated.
PubMed: 34463526
DOI: 10.1094/PDIS-06-21-1271-PDN -
Frontiers in Plant Science 2023Abiotic stress, especially salt stress, is one of the major barriers to crop production worldwide. Crops like onion that belong to the glycophytic group are more...
Abiotic stress, especially salt stress, is one of the major barriers to crop production worldwide. Crops like onion that belong to the glycophytic group are more sensitive to salinity stress. A huge study regarding the influence of salinity stress on the growth and development of crops has already been done and is still ongoing. One of the major targets of the research is to develop genotypes that have enhanced performance under stress environments. The world needs more of these types of genotypes to combat the ever-growing salt-stressed soils. Therefore, a number of germplasm were studied during the 2019-2020 and 2020-2021 seasons under different salt concentrations to identify tolerant genotypes as well as to study the plants' responses at different growth stages against elevated salinity levels. A 2-year study was conducted where germination potential was evaluated in the first year and carried out in petri dish culture of seeds, followed by plastic pot culture for plant establishment and bulb development evaluation during the second year. Four different saline water solutions having different salt concentrations (0, 8, 10, and 12 dS m) were applied to the petri dishes and pots as the source of water for plants in both seasons. Results indicated that a significant reduction in plants' performance occurs under higher salinity levels. Salt concentration had an adverse impact on germination, leaf development and growth, the height of plants, bulb size and shape, and the bulb weight of onion. All the growth phases of onion are sensitive to elevated concentrations. Variable performances were observed in the genotypes under stress conditions, and a few genotypes (Ac Bog 409, Ac Bog 414, Ac Bog 424, Ac Bog 430, Ac Bog 417, Ac Bog 419, Ac Bog 420, Ac Bog 422, and Ac Bog 425) having some sort of tolerance to salt stress were identified, which might be recommended for mass production. Tolerance indices could successfully be applied in selecting the salt-tolerant genotypes. Thus, the present findings and the identified genotypes could be further utilized in salt stress improvement research on onion.
PubMed: 37063224
DOI: 10.3389/fpls.2023.1154051 -
European Review For Medical and... Dec 2022Dexpanthenol is an ingredient in multiple topical pharmaceutical preparations thanks to its high penetration and localized concentration. It is included in many...
OBJECTIVE
Dexpanthenol is an ingredient in multiple topical pharmaceutical preparations thanks to its high penetration and localized concentration. It is included in many ointments or lotions for dermatological use, assisting in healing and reducing pruritus. Vaseline is a synthetic product obtained by distilling crude oil. It is commercially available in several grades. The study presented here examined how topically applied agents (dexpanthenol or vaseline) affect nasal epithelial cells in culture. In particular, the study aimed to identify any alterations to epithelial cells which might indicate toxicity.
MATERIALS AND METHODS
The nasal epithelial cells used were sourced from mucosal tissue fragments left over the following septorhinoplasty on five patients not suffering from rhinosinusitis. The first step was to dissect the mucosal fragments into smaller pieces on a sterilized Petri dish. These fragments were then placed into the DMEM-F12 cell culture medium, which had been freshly prepared. The dexpanthenol and vaseline were diluted in dimethylsulfoxide (DMSO) to a concentration of 5 mg/mL. The cells in the wells were exposed to varying concentrations of dexpanthenol or vaseline. The actual concentration of the test reagent to which the epithelial cells were exposed ranged from 0.15 mg/mL to 5 mg/mL. The exposure period was 24 hours. The cells were finally examined using a Leica SP5II confocal microscope. The features sought were DNA fragmentation, condensation of the nuclei, changes in the outer membrane, or cytoskeletal abnormality. These features, if present, indicate cytotoxicity.
RESULTS
The viability of the cultured nasal epithelial cells was unaltered by a 24-hour exposure to dexpanthenol, nor was the cellular proliferation rate affected at the level of statistical significance. There was evidence of a cytotoxic effect from exposing nasal epithelial cells to vaseline in liquid form for 24 hours. There was a reduction in cellular viability in the plates where the highest dose of vaseline (5 mg/mL) was used. Cellular viability was not affected significantly at any of the doses below 5 mg/mL.
CONCLUSIONS
The absence of cytotoxic effects from the application of dexpanthenol to the nasal mucosa indicates that this agent may be safely used within the nose. The cytotoxic effects of liquid vaseline observed in this trial (condensed nuclear chromatin, loss of cellular volume) indicate that this agent may be harmful when used intranasally. For patients who require nasal packing due to nose bleeds or following endoscopic sinus surgical procedures, dexpanthenol should be preferred to vaseline from the point of view of maximizing healing of a nasal injury.
Topics: Humans; Excipients; Petrolatum; Sinusitis; Pantothenic Acid
PubMed: 36524920
DOI: 10.26355/eurrev_202212_30496 -
PloS One 2020Spissistilus festinus (Say) (Hemiptera: Membracidae) was shown to transmit Grapevine red blotch virus (GRBV) in a greenhouse study. Grapevines infected with GRBV exhibit...
Spissistilus festinus (Say) (Hemiptera: Membracidae) was shown to transmit Grapevine red blotch virus (GRBV) in a greenhouse study. Grapevines infected with GRBV exhibit reduced sugar accumulation, altered secondary metabolite production and delayed berry maturation that negatively impacts wine quality and economics. Augmentative biocontrol may be a useful integrated pest management (IPM) tool for suppressing S. festinus populations in vineyards, but minimal research has been conducted on testing potential predators against the different life stages of S. festinus. The susceptibility of S. festinus adults and nymphs (1st through 5th instar) to predation by six commercially available biocontrol agents in petri dish and bell bean plant arenas was determined under greenhouse conditions. No significant mortality of S. festinus nymphs or adults occurred when exposed to Cryptolaemus montrouzieri adults, C. montrouzieri larvae and Sympherobius barberi adults in petri dish or bell bean plant arenas. Significant mortality of 1st and 2nd instar nymphs of S. festinus in the presence of Zelus renardii nymphs was observed in petri dish but not in bell bean arenas. Hippodamia convergens adults and Chrysoperla rufilabris larvae both consumed a significant number of S. festinus nymphs in petri dish and bell bean arenas. No significant predation of S. festinus adults was documented in this experiment. Results of this study aid in identifying predators that may be suitable candidates for additional field testing to determine their potential efficacy as biocontrol agents of S. festinus in a vineyard setting.
Topics: Animals; Coleoptera; Food Chain; Geminiviridae; Hemiptera; Models, Biological; Nymph; Predatory Behavior
PubMed: 33253247
DOI: 10.1371/journal.pone.0242775 -
Scientific Reports Jul 2023The mechanisms governing chemotaxis in Chlamydomonas reinhardtii are largely unknown compared to those regulating phototaxis despite equal importance on the migratory...
The mechanisms governing chemotaxis in Chlamydomonas reinhardtii are largely unknown compared to those regulating phototaxis despite equal importance on the migratory response in the ciliated microalga. To study chemotaxis, we made a simple modification to a conventional Petri dish assay. Using the assay, a novel mechanism governing Chlamydomonas ammonium chemotaxis was revealed. First, we found that light exposure enhances the chemotactic response of wild-type Chlamydomonas strains, yet phototaxis-incompetent mutant strains, eye3-2 and ptx1, exhibit normal chemotaxis. This suggests that Chlamydomonas transduces the light signal pathway in chemotaxis differently from that in phototaxis. Second, we found that Chlamydomonas collectively migrate during chemotaxis but not phototaxis. Collective migration during chemotaxis is not clearly observed when the assay is conducted in the dark. Third, the Chlamydomonas strain CC-124 carrying agg1, the AGGREGATE1 gene (AGG1) null mutation, exhibited a more robust collective migratory response than strains carrying the wild-type AGG1 gene. The expression of a recombinant AGG1 protein in the CC-124 strain suppressed this collective migration during chemotaxis. Altogether, these findings suggest a unique mechanism; ammonium chemotaxis in Chlamydomonas is mainly driven by collective cell migration. Furthermore, it is proposed that collective migration is enhanced by light and suppressed by the AGG1 protein.
Topics: Chlamydomonas reinhardtii; Chemotaxis; Ammonium Compounds; Chlamydomonas; Cell Movement; Light
PubMed: 37402785
DOI: 10.1038/s41598-023-36818-6 -
Environmental Health Perspectives Nov 2020Exposure to a diverse environmental microbiome is thought to play an important role in "educating" the immune system and facilitating competitive exclusion of pathogens...
BACKGROUND
Exposure to a diverse environmental microbiome is thought to play an important role in "educating" the immune system and facilitating competitive exclusion of pathogens to maintain human health. Vegetation and soil are key sources of airborne microbiota--the aerobiome. A limited number of studies have attempted to characterize the dynamics of near surface green space aerobiomes, and no studies to date have investigated these dynamics from a vertical perspective. Vertical stratification in the aerobiome could have important implications for public health and for the design, engineering, and management of urban green spaces.
OBJECTIVES
The primary objectives of this study were to: ) assess whether significant vertical stratification in bacterial species richness and evenness (alpha diversity) of the aerobiome occurred in a parkland habitat in Adelaide, South Australia; ) assess whether significant compositional differences (beta diversity) between sampling heights occurred; and ) to preliminarily assess whether there were significant altitudinal differences in potentially pathogenic and beneficial bacterial taxa.
METHODS
We combined an innovative columnar sampling method at soil level, 0.0, 0.5, 1.0, and , using passive petri dish sampling to collect airborne bacteria. We used a geographic information system (GIS) to select study sites, and we used high-throughput sequencing of the bacterial 16S rRNA gene to assess whether significant vertical stratification of the aerobiome occurred.
RESULTS
Our results provide evidence of vertical stratification in both alpha and beta (compositional) diversity of airborne bacterial communities, with diversity decreasing roughly with height. We also found significant vertical stratification in potentially pathogenic and beneficial bacterial taxa.
DISCUSSION
Although additional research is needed, our preliminary findings point to potentially different exposure attributes that may be contingent on human height and activity type. Our results lay the foundations for further research into the vertical characteristics of urban green space aerobiomes and their implications for public health and urban planning. https://doi.org/10.1289/EHP7807.
Topics: Air Microbiology; Cities; Environmental Monitoring; Humans; Microbiota; Parks, Recreational
PubMed: 33236934
DOI: 10.1289/EHP7807 -
Advanced Science (Weinheim,... Dec 2020There is an unmet demand for microfluidics in biomedicine. This paper describes contactless fabrication of microfluidic circuits on standard Petri dishes using just a...
There is an unmet demand for microfluidics in biomedicine. This paper describes contactless fabrication of microfluidic circuits on standard Petri dishes using just a dispensing needle, syringe pump, three-way traverse, cell-culture media, and an immiscible fluorocarbon (FC40). A submerged microjet of FC40 is projected through FC40 and media onto the bottom of a dish, where it washes media away to leave liquid fluorocarbon walls pinned to the substrate by interfacial forces. Such fluid walls can be built into almost any imaginable 2D circuit in minutes, which is exploited to clone cells in a way that beats the Poisson limit, subculture adherent cells, and feed arrays of cells continuously for a week. This general method should have wide application in biomedicine.
PubMed: 33304750
DOI: 10.1002/advs.202001854 -
Plants (Basel, Switzerland) May 2022Plant monoterpenes have received attention for their ecological functions and as potential surrogates for synthetic herbicides, but very little is known about the...
Plant monoterpenes have received attention for their ecological functions and as potential surrogates for synthetic herbicides, but very little is known about the processes that govern their behavior in the soil environment, and even less about the possible enantioselectivity in the functions and environmental behavior of chiral monoterpenes. We characterized the adsorption and dissipation of the two enantiomers of the chiral monoterpene pulegone in different soils, and their phytotoxicity to different plant species through Petri dish and soil bioassays. R- and S-pulegone displayed a low-to-moderate non-enantioselective adsorption on the soils that involved weak interaction mechanisms. Soil incubation experiments indicated that, once in the soil, R- and S-pulegone are expected to suffer rapid volatilization and scarcely enantioselective, biodegradation losses. In Petri dishes, the phytotoxicity of pulegone and its enantioselectivity to , , and was species-dependent. was the most sensitive species and showed higher susceptibility to S- than to R-pulegone. Biodegradation and volatilization losses greatly reduced the phytotoxic activity of S-pulegone applied to soil, but the addition of a highly-adsorptive organoclay stabilized the monoterpene and increased its phytotoxic effect. Stabilization by adsorption may represent an important mechanism by which the bioactivity of plant monoterpenes in soils can be increased.
PubMed: 35631720
DOI: 10.3390/plants11101296 -
Plant Disease Jun 2022Grapevine is one of the most widely-planted fruit crops in the world, and is the most economically important fruit crop in the state of New York, USA. Symptoms of...
Grapevine is one of the most widely-planted fruit crops in the world, and is the most economically important fruit crop in the state of New York, USA. Symptoms of anthracnose on grapevine are similarly widely-reported on grapevine fruit and foliage, and such symptoms are commonly attributed to Elsinöe ampelina (Wilcox et al., 2015). However, similar symptoms, if not identical, to those associated with E. ampelina have been sporadically attributed to various species in the genus Colletotrichum. In September 2021, a survey was conducted in three research vineyards at Cornell AgriTech in Geneva, NY. Symptoms of anthracnose werebserved on four Vitis interspecific hybrid breeding lines in a 1 ha vineyard. Leaves, fruit, and petioles showing symptoms of anthracnose, i.e., sunken necrotic lesions with grayish centers and brownish margins, were collected. Symptomatic and healthy portions of surface-sterilized tissues were placed on PDA medium and incubated at 23oC for 7 days. Several petiole samples yielded colonies of white to greyish mycelium, with some red to orange pigmentation (Fig. 1A and 1B), similar to those described by Chowdappa et al. (2009) for Colletotrichum species isolated from grapevine in India. Cultures were allowed to sporulate. Slides from cultures were prepared and examined at 400X magnification. Conidia from cultures were cylindrical with rounded ends, 13.5-15.2 μm in length and 7.6-9.0 μm in width (Fig. 1C). Koch's postulates were fulfilled by inoculating detached healthy leaves of V. vinifera 'Chardonnay' that had been surface sterilized in 10% sodium hypochlorite and triple-rinsed in sterile distilled water. Drop inoculation was used from a suspension of 105 conidia/ml from the foregoing pure cultures as five 2 µL droplets per leaf. Inoculated detached leaves were maintained on water agar in a Petri dish at 23oC. Four days after inoculation, symptoms were observed and compared with the originally collected samples. Inoculated leaves displayed symptoms typically found on the collected tissues, and the original pathogen, as confirmed by colony morphology and conidial characteristics and dimensions, was reisolated from inoculated leaves, and not from non-inoculated controls. For molecular characterization, fungal DNA was isolated by using Qiagen DNeasy kit and amplified using the following primer pairs: ITS1/ITS4, TEF (Hyun et al., 2009), E. ampelina F/R (Santos et al. 2018), TUB2, ACT, HIS3, GAPDH and CHS1 (Damm et al., 2001). PCR products were purified using ExoSAP-IT, and samples were Sanger sequenced. Sequences were analyzed using Geneious Prime software, and the resulting sequences (NCBI accessions OL720215, OL720216, OL720217, OL720218, OL853836, OM982612, OM982613, OM982614, OM982615 and OM982616) had 94 to 100% identity to Colletotrichum fioriniae NCBI accessions MN944922.1, MK646015.1, MN944922.1, MN856415.1, KU847413.1, MN520490.1, MN544294.1, KY695259.1, MN535117.1 and MN544295.1. Symptoms of grapevine anthracnose caused by Colletotrichum species have been reported from India (Chowdappa et al., 2009) and Korea (Kim et al., 2021). To our knowledge this is the first report of grapevine anthracnose caused by C. fioriniae Anthracnose and ripe rot are diseases of increasing importance, particularly as new grapevine cultivars with resistance to powdery mildew or downy mildew are adopted. Taxonomy of the causal agents (E. ampelina and Colletotrichum spp.) has undergone considerable revision. Consequently, distribution and relative prevalence of the various taxa will require further study.
PubMed: 35771116
DOI: 10.1094/PDIS-03-22-0604-PDN -
Journal of Nematology 2020induce necrotic lesions, the hallmark symptom for the genus, soon after infection. The objective of our study was to characterize and quantify gender differences in...
induce necrotic lesions, the hallmark symptom for the genus, soon after infection. The objective of our study was to characterize and quantify gender differences in lesion development. Independent experiments were conducted for three hosts; pea ( L. cv. Early Alaskan), dill ( cv. Long Island Mammoth), and alfalfa ( cv. Vernal). Each experimental unit was an excised radical placed on water agar in a Petri dish and inoculated with either 40 adult males or 40 fourth-stage juvenile females. Length, size, and number of lesions were recorded during the experiment and the radicals were harvested 14 days after introducing nematodes. Lesions were first observed on pea after two days for female-inoculated roots, and 24 hr after introducing both genders to dill and alfalfa. Lesions expanded either by multiple lesions coalescing or individual lesions expanding over time. Males made fewer, smaller lesions with less discoloration for all three hosts. There was no difference among genders for the total number of nematodes recovered per Petri dish or the number of endoparasitic nematodes after 14 days. The survival rate of males and females at harvest was not different, indicating that the difference in lesion formation was not related to nematode population densities. This study verified and quantified the observation that lesions induced by males are less extensive and in smaller numbers than lesions by females.
PubMed: 33842893
DOI: 10.21307/jofnem-2020-090