scholarly journals Diseases of S. halepense: Possible Role as a Reservoir of Pathogens to Other Plants

Weed Science ◽  
2021 ◽  
pp. 1-61
Author(s):  
Ezekiel Ahn ◽  
Louis K. Prom ◽  
Clint Magill
Keyword(s):  
Sorghum Halepense ◽  
Sequence Information ◽  
Pathogen Identification ◽  
Disease Symptoms ◽  
Noxious Weeds ◽  
Potential Reservoir ◽  
Disease Agent ◽  
Pathogen Reservoir ◽  
Wide Dissemination

Abstract Johnsongrass [Sorghum halepense (L.) Pers.] is one of the most noxious weeds distributed around the world. Due to rapid growth, wide dissemination, seeds that can germinate after years in the soil and ability to spread via rhizomes, S. halepense is difficult to control. From a perspective of plant pathology, Johnsongrass is also a potential reservoir of pathogens that can eventually jump to other crops, especially corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench]. As one of the most problematic weeds, understanding S. halepense and its diseases can provide useful information concerning its role in diseases of agronomically important crops. An alternative consideration is that S. halepense may provide a source of genes for resistance to pathogens. While some studies have verified that pathogens isolated from S. halepense actually cause disease on host crops through cross inoculation, similarity of disease symptoms and pathogen morphology have been used for identity of the disease agent in most studies. Availability of DNA sequence information has greatly altered and improved pathogen identification, leading to significant changes in phylogenetic assignments. Reclassification of pathogens, especially fungi, raises new questions concerning the role of S. halepense as a disease reservoir. Our goals in this review are to pinpoint, where possible, diseases where S. halepense acts as a significant pathogen reservoir and to point out problem areas where further research is needed.

scholarly journals Staphylococcal Communities on Skin Are Associated with Atopic Dermatitis and Disease Severity

2021 ◽  
Vol 9 (2) ◽  
pp. 432
Author(s):  
Sofie Marie Edslev ◽  
Caroline Meyer Olesen ◽  
Line Brok Nørreslet ◽  
Anna Cäcilia Ingham ◽  
Søren Iversen ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Alpha Diversity ◽  
Skin Microbiota ◽  
Specific Primers ◽  
Staphylococcus Lugdunensis ◽  
Disease Symptoms ◽  
Lesional Skin ◽  
Staphylococcus Capitis ◽  
Staphylococcus Hominis

The skin microbiota of atopic dermatitis (AD) patients is characterized by increased Staphylococcus aureus colonization, which exacerbates disease symptoms and has been linked to reduced bacterial diversity. Skin bacterial communities in AD patients have mostly been described at family and genus levels, while species-level characterization has been limited. In this study, we investigated the role of the bacteria belonging to the Staphylococcus genus using targeted sequencing of the tuf gene with genus-specific primers. We compared staphylococcal communities on lesional and non-lesional skin of AD patients, as well as AD patients with healthy controls, and determined the absolute abundance of bacteria present at each site. We observed that the staphylococcal community, bacterial alpha diversity, and bacterial densities were similar on lesional and non-lesional skin, whereas AD severity was associated with significant changes in staphylococcal composition. Increased S. aureus, Staphylococcus capitis, and Staphylococcus lugdunensis abundances were correlated with increased severity. Conversely, Staphylococcus hominis abundance was negatively correlated with severity. Furthermore, S. hominis relative abundance was reduced on AD skin compared to healthy skin. In conclusion, various staphylococcal species appear to be important for skin health.

scholarly journals The Effect of Fusarium verticillioides Fumonisins on Fatty Acids, Sphingolipids, and Oxylipins in Maize Germlings

2021 ◽  
Vol 22 (5) ◽  
pp. 2435
Author(s):  
Marzia Beccaccioli ◽  
Manuel Salustri ◽  
Valeria Scala ◽  
Matteo Ludovici ◽  
Andrea Cacciotti ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fusarium Verticillioides ◽  
Fungal Growth ◽  
Defense Responses ◽  
Ceramide Synthase ◽  
Ear Rot ◽  
In Planta ◽  
Disease Symptoms ◽  
The Impact

Fusarium verticillioides causes multiple diseases of Zea mays (maize) including ear and seedling rots, contaminates seeds and seed products worldwide with toxic chemicals called fumonisins. The role of fumonisins in disease is unclear because, although they are not required for ear rot, they are required for seedling diseases. Disease symptoms may be due to the ability of fumonisins to inhibit ceramide synthase activity, the expected cause of lipids (fatty acids, oxylipins, and sphingolipids) alteration in infected plants. In this study, we explored the impact of fumonisins on fatty acid, oxylipin, and sphingolipid levels in planta and how these changes affect F. verticillioides growth in maize. The identity and levels of principal fatty acids, oxylipins, and over 50 sphingolipids were evaluated by chromatography followed by mass spectrometry in maize infected with an F. verticillioides fumonisin-producing wild-type strain and a fumonisin-deficient mutant, after different periods of growth. Plant hormones associated with defense responses, i.e., salicylic and jasmonic acid, were also evaluated. We suggest that fumonisins produced by F. verticillioides alter maize lipid metabolism, which help switch fungal growth from a relatively harmless endophyte to a destructive necrotroph.

scholarly journals Interaction of the Tobacco Mosaic Virus Replicase Protein with the Aux/IAA Protein PAP1/IAA26 Is Associated with Disease Development

2005 ◽  
Vol 79 (4) ◽  
pp. 2549-2558 ◽  
Author(s):  
Meenu S. Padmanabhan ◽  
Sameer P. Goregaoker ◽  
Sheetal Golem ◽  
Haiymanot Shiferaw ◽  
James N. Culver
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Protein S ◽  
Helicase Domain ◽  
Auxin Response ◽  
Disease Symptoms ◽  
Developmental Abnormalities ◽  
Replicase Protein ◽  
Transcriptional Alterations

ABSTRACT Virus-infected plants often display developmental abnormalities that include stunting, leaf curling, and the loss of apical dominance. In this study, the helicase domain of the Tobacco mosaic virus (TMV) 126- and/or 183-kDa replicase protein(s) was found to interact with the Arabidopsis Aux/IAA protein PAP1 (also named IAA26), a putative regulator of auxin response genes involved in plant development. To investigate the role of this interaction in the display of symptoms, a TMV mutant defective in the PAP1 interaction was identified. This mutant replicated and moved normally in Arabidopsis but induced attenuated developmental symptoms. Additionally, transgenic plants in which the accumulation of PAP1 mRNA was silenced exhibit symptoms like those of virus-infected plants. In uninfected tissues, ectopically expressed PAP1 accumulated and localized to the nucleus. However, in TMV-infected tissues, PAP1 failed to accumulate to significant levels and did not localize to the nucleus, suggesting that interaction with the TMV replicase protein disrupts PAP1 localization. The consequences of this interaction would affect PAP1's putative function as a transcriptional regulator of auxin response genes. This is supported by gene expression data indicating that ∼30% of the Arabidopsis genes displaying transcriptional alterations in response to TMV contain multiple auxin response promoter elements. Combined, these data indicate that the TMV replicase protein interferes with the plant's auxin response system to induce specific disease symptoms.

scholarly journals Multiple-Locus Sequence Typing and Analysis of Toxin Genes in Bacillus cereus Food-Borne Isolates

2007 ◽  
Vol 74 (3) ◽  
pp. 850-860 ◽  
Author(s):  
Barbara Cardazzo ◽  
Enrico Negrisolo ◽  
Lisa Carraro ◽  
Leonardo Alberghini ◽  
Tomaso Patarnello ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Bacillus Cereus ◽  
Reticulate Evolution ◽  
Sequence Information ◽  
Data Set ◽  
Group I ◽  
Food Borne ◽  
Public Data ◽  
Encoding Genes

ABSTRACT In the present study we characterized 47 food-borne isolates of Bacillus cereus using multilocus sequence typing (MLST). Newly determined sequences were combined with sequences available in public data banks in order to produce the largest data set possible. Phylogenetic analysis was performed on a total of 296 strains for which MLST sequence information is available, and three main lineages—I, II, and III—within the B. cereus complex were identified. With few exceptions, all food-borne isolates were in group I. The occurrence of horizontal gene transfer (HGT) among various strains was analyzed by several statistical methods, providing evidence of widespread lateral gene transfer within B. cereus. We also investigated the occurrence of toxin-encoding genes, focusing on their evolutionary history within B. cereus. Several patterns were identified, indicating a pivotal role of HGT in the evolution of toxin-encoding genes. Our results indicate that HGT is an important element in shaping the population structure of the B. cereus complex. The results presented here also provide strong evidence of reticulate evolution within the B. cereus complex.

scholarly journals Trypanosome infections in naturally infected horses and donkeys of three active sleeping sickness foci in the south of Chad

2020 ◽  
Author(s):  
Joël Vourchakbé ◽  
Arnol Auvaker Tiofack ◽  
Mbida Mpoame ◽  
Gustave Simo
Keyword(s):  
Capillary Tube ◽  
Control Strategies ◽  
Clinical Signs ◽  
Sleeping Sickness ◽  
Diagnostic Methods ◽  
Trypanosome Species ◽  
Blood Samples ◽  
Potential Reservoir ◽  
Objective Being

Abstract Background Equine trypanosomiases are complex infectious diseases with overlapping clinical signs defined by their mode of transmission. Despite their economic impacts, these diseases have been neglected by the scientific community, the veterinary authorities and regulatory organizations. To fill the observed knowledge gap, we undertook the identification of different trypanosome species and subspecies naturally infecting horses and donkeys within the Chadian sleeping sickness focus. The end objective, being to investigate the potential role of these domestic animals as reservoirs of the human infective Trypanosoma brucei gambienseMethod Blood samples were collected from 155 donkeys and 131 horses in three human African trypanosomiasis (HAT) foci of Chad. Rapid diagnostic test (RDT) and capillary tube centrifugation (CTC) test were used to search for trypanosome infections. DNA was extracted from each blood sample and different trypanosome species and subspecies were identified with molecular tools.Results From 286 blood samples collected, 54 (18.9%) and 36 (12.6%) were respectively positive for RDT and CTC. PCR revealed 144 (50.3%) animals with trypanosome infections. The kappa Cohen coefficients used to evaluate the concordance between the diagnostic methods were low; ranging from 0.087±0.0473 to 0.48 ± 0.0698. Trypanosomes of the subgenus Trypanozoon were the most prevalent (29.4%), followed by T. congolense forest (11.5%), T. congolense savannah (4.9%) and T. vivax (4.5%). Two donkeys and one horse from the Maro HAT focus were found with T. b. gambiense infections. Between animal species and HAT foci, no significant differences were observed in the infection rates of different trypanosomes. Conclusion This study revealed several trypanosome species and sub species in donkeys and horses, highlighting the existence of AAT in HAT foci of Chad. The identification of T. b. gambiense in donkeys and horses suggests considering these animals as potential reservoir for HAT in Chad. The presence of both human-infective and human non infective trypanosomes species highlights the need for developing joined control strategies for HAT and AAT.

Deletion mutants which affect the nuclease-sensitive site in simian virus 40 chromatin

1982 ◽  
Vol 2 (7) ◽  
pp. 782-788
Author(s):  
R D Gerard ◽  
M Woodworth-Gutai ◽  
W A Scott
Keyword(s):  
Simian Virus 40 ◽  
Simian Virus ◽  
Deletion Mutants ◽  
Sequence Information ◽  
Base Pairs ◽  
Deletion Mutations ◽  
Sensitive Site ◽  
Late Side ◽  
Nuclease Sensitivity

A short segment of simian virus 40 (SV40) chromatin on the late side of the origin of replication is hypersensitive to nuclease cleavage. The role of DNA sequence information in this nuclease-sensitive feature was examined by constructing deletion mutations in this region. Deletions were introduced into the inserted segment of in(Or)-1411 (a viable, partially duplicated variant of SV40), and nuclease sensitivity of the inserted segment was compared with that of the unaltered sequences in their normal location in the viral genome. Extended deletions (118 to 161 base pairs) essentially abolished nuclease sensitivity within the inserted segment. Shorter deletions (21 to 52 base pairs) at separate locations retained the nuclease-sensitive feature. In some short-deletion mutants nuclease susceptibility was substantially reduced. We conclude that more than one genetic element in this region contributes to the organization of the nuclease-sensitive feature and that the SV40 72-base repeat is not, in itself, sufficient signal for this feature.

scholarly journals Application of kDNA Minicircle PCR-RFLP to Characterize Leishmania donovani Clinical Isolates Obtained from Post-Kala-Azar Dermal Leishmaniasis in Eastern Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ojesh Pokhrel ◽  
Keshav Rai ◽  
Narayan Raj Bhattarai ◽  
Suman Rijal ◽  
Arpana Rijal ◽  
...  
Keyword(s):  
Leishmania Donovani ◽  
Clinical Isolates ◽  
Rdna Genes ◽  
Kala Azar ◽  
Pcr Rflp ◽  
Potential Reservoir ◽  
Rflp Assay ◽  
Epidemiological Characterization

Post-kala-azar dermal leishmaniasis (PKDL) is a skin manifestation of visceral leishmaniasis (VL) which develops after apparent cure in some patients. PKDL is considered as the potential reservoir for the VL infection. Molecular epidemiological characterization of L. donovani isolates obtained from VL and PKDL isolates is essentially required in order to understand the transmission dynamics of the VL infection. To date, genetic variation among the VL and PKDL L. donovani isolates was not fully elucidated. Therefore, 14 clinical isolates from VL and 4 clinical isolates from PKDL were speciated by hsp70 and rDNA genes. Further characterization of L. donovani by haspB PCR demonstrates two different genotypes. All PKDL isolates have the same genetic structure. kDNA PCR-RFLP assay revealed 18 different genotypes; however, structural analysis showed the two distinct kDNA genotype population (k = 2). The kDNA fingerprint patterns of parasites from hilly districts were clustered separately from low-land districts. Therefore, further study with a large number of samples is urgently required for systematic characterization of the clinical isolates to track the molecular epidemiology of the Leishmania donovani causing VL and the role of PKDL as a reservoir.

scholarly journals Key Aspects on the Biology, Ecology and Impacts of Johnsongrass [Sorghum halepense (L.) Pers] and the Role of Glyphosate and Non-Chemical Alternative Practices for the Management of This Weed in Europe

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 717 ◽  
Author(s):  
Travlos ◽  
Montull ◽  
Kukorelli ◽  
Malidza ◽  
Dogan ◽  
...  
Keyword(s):  
Weed Management ◽  
Control Plant ◽  
Field Trials ◽  
European Countries ◽  
Alternative Methods ◽  
Sorghum Halepense ◽  
Current Status ◽  
Integrated Weed Management ◽  
Alternative Practices

Sorghum halepense (L.) Pers is a common and noxious worldwide weed of increasing distribution in many European countries. In the present review, information on the biology, ecology, agricultural, economic and environmental impact of johnsongrass is given, and the current status of this weed in Europe is discussed. Furthermore, special attention is given to the important role of field trials using glyphosate to control weeds in arable and perennial crops in many European countries. Some of the factors which affect control efficacy and should be taken into account are also discussed. Finally, several non-chemical alternative methods (cultural, mechanical, thermal, biological, etc.) for johnsongrass management are also presented. The adoption of integrated weed management (IWM) techniques such as glyphosate use, crop rotation, and deep tillage is strongly recommended to control plant species that originate from both seed and rhizomes.

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