scholarly journals Botryosphaeria Tree Fungal Pathogens and Their Diversity

2021 ◽  
Vol 10 (1) ◽  
pp. ACCEPTED
Author(s):  
Wendu A. Darge ◽  
Samuel S. Woldemariam
Keyword(s):  
Fungal Pathogens ◽  
Global Climate ◽  
Its Region ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Nutrient Deficiencies ◽  
Morphological Findings ◽  
Optimal Health ◽  
Molecular Phylogenetic ◽  
Host Tree Species

The genus Botryosphaeria identified in 1863 as saprophytes of dead tissue of woody plants have been described as pathogens of economically important plantation trees in agriculture and native forests. The genus is a species-rich, worldwide distributed occurring on diverse host ranges. Species of the Botryosphaeria are reported as the pathogens of many plantation trees, including species of Acacia, Eucalyptus, and Pinus causing canker and rapid dieback diseases which often end up in death. Botryosphaeria fungal pathogens have cross pathogenicity on different host tree species which enables them important and focus area of research. The taxonomy of Botryosphaeria spp. have been under research, identification of these fungi has generally been based on morphological features of the anamorph that usually seen under the microscope. Characters that are used to classify genera in the Botryosphaeria have mostly relied on the macroscopic features of the ascospores and the conidial features. Currently, molecular techniques such as DNA sequencing involving amplification of ITS region are important for exact identification of the genera to species level. Recent molecular, phylogenetic and morphological findings showed that order Botryosphaeriales is diverse consisting nine families and 33 genera with 23 genera only in the family Botryosphaeriaceae. Botryosphaeria spp. are naturally endophytes associated with tree plants known to cause monocyclic or polycyclic diseases resulting in polyetic epidemics. The factor that makes plants more prone to Botryosphaeria fungal species is assumed to be stress or wounding associated with the host plants. Global climate change driven drought is an important factor that initiate stress resulting in nutrient deficiencies. Botryosphaeria fungal tree diseases can be best managed by ensuring plants are in optimal health through appropriate integration of cultural, silvicultural and fungicidal applications to effectively prevent and control the diseases.

scholarly journals The Use of Galleria mellonella Larvae to Identify Novel Antimicrobial Agents against Fungal Species of Medical Interest

2018 ◽  
Vol 4 (3) ◽  
pp. 113 ◽  
Author(s):  
Kevin Kavanagh ◽  
Gerard Sheehan
Keyword(s):  
Fungal Pathogens ◽  
Antimicrobial Agents ◽  
Galleria Mellonella ◽  
Fungal Infections ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Antifungal Drugs ◽  
Immune Priming ◽  
Greater Wax Moth

The immune system of insects and the innate immune response of mammals share many similarities and, as a result, insects may be used to assess the virulence of fungal pathogens and give results similar to those from mammals. Larvae of the greater wax moth Galleria mellonella are widely used in this capacity and also for assessing the toxicity and in vivo efficacy of antifungal drugs. G. mellonella larvae are easy to use, inexpensive to purchase and house, and have none of the legal/ethical restrictions that are associated with use of mammals. Larvae may be inoculated by intra-hemocoel injection or by force-feeding. Larvae can be used to assess the in vivo toxicity of antifungal drugs using a variety of cellular, proteomic, and molecular techniques. Larvae have also been used to identify the optimum combinations of antifungal drugs for use in the treatment of recalcitrant fungal infections in mammals. The introduction of foreign material into the hemocoel of larvae can induce an immune priming effect which may operate independently with the activity of the antifungal drug. Procedures to identify this effect and limit its action are required.

scholarly journals Molecular characterization of fungi associated with stored soybean (Glycine max L) seeds

2020 ◽  
Vol 36 (2) ◽  
pp. 27-32
Author(s):  
C.G. Ikechi-Nwogu ◽  
F.C. Okene
Keyword(s):  
Fungal Pathogens ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Local Alignment ◽  
Post Harvest ◽  
High Quality Protein ◽  
Search Tool ◽  
Food And Feed ◽  
Glycine Max L

Soybean is an important legume that has high quality protein and oil for food and feed. Despite the importance of this legume, the crop is affected by several post-harvest diseases caused by fungi. A study was carried out to identify the fungal species associated with the seeds of soybean using molecular techniques. The DNA of the isolate, was molecularly characterized using Internal Transcribed Spacer 1 (ITS-1) molecular marker. The isolate DNA sequence, was aligned using the Basic Local Alignment Search Tool for nucleotide (BLASTN) 2.8.0 version of the National Center for Biotechnology Information (NCBI) database. The results showed that the isolate sequence was 98% identical to Diaporthe spp. Voucher VP51, 98% identical to Diaporthe schini isolate L5N71 and 98% identical to Diaporthe schini strain B125. These findings showed that Diaporthe spp. is one of the causal fungal pathogens of post-harvest diseases of soybean seeds. It is anticipated that these results will provide information on culturing Diaporthe species also provide the basis for further study to show their antibiotic and anti-cancerous, enzymes and secondary metabolites producing ability. Keywords: Soybean, Diaporthe schini and RBCL marker

scholarly journals Identification and Pathogenicity of Fungal Pathogens Associated with Stem-End Rot of Avocado in California

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1580-1584 ◽  
Author(s):  
M. Twizeyimana ◽  
H. Förster ◽  
V. McDonald ◽  
D. H. Wang ◽  
J. E. Adaskaveg ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Southern California ◽  
Colletotrichum Gloeosporioides ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Pathogenicity Test ◽  
Avocado Fruit ◽  
Low Humidity ◽  
Neofusicoccum Luteum

Stem-end rot of harvested avocado fruit commonly occurs wherever the crop is cultivated. Multiple fungal species have been described as causal agents. To determine the causal pathogens of stem-end rot in California, fungal isolations were conducted from symptomatic fruit, and fungi were identified by morphological and molecular techniques. In 2010 and 2011, a total of 177 isolates were recovered from 290 avocado fruit collected from seven orchards in one of the major avocado growing areas in Southern California. The majority of isolates was identified as Neofusicoccum luteum (65%), with the remainder either as Colletotrichum gloeosporioides (33%) or Phomopsis sp. (2%). In a pathogenicity test, N. luteum caused significantly (P < 0.05) more severe stem-end rot than either C. gloeosporioides or Phomopsis sp. No significant (P > 0.05) differences in stem-end rot severity were observed between inoculations with N. luteum isolated from fruit stem-end rot and N. luteum or N. parvum isolated from branch cankers. This confirms that stem-end rot of avocado can be initiated by fungi causing branch cankers. Although low humidity and rainfall during much of the growing and harvest seasons in California are considered unfavorable conditions for the development of avocado stem-end rot, the identification of the causal pathogens is of value when decays have to be managed during outbreaks, and it stresses the importance of managing branch cankers.

scholarly journals Updates on the Taxonomy of Mucorales with an Emphasis on Clinically Important Taxa

2019 ◽  
Vol 5 (4) ◽  
pp. 106 ◽  
Author(s):  
Walther ◽  
Wagner ◽  
Kurzai
Keyword(s):  
Fungal Pathogens ◽  
Its Region ◽  
Mucor Circinelloides ◽  
Rhizopus Microsporus ◽  
Human Environment ◽  
Important Species ◽  
Phylogenetic Studies ◽  
Molecular Phylogenetic ◽  
Life Threatening ◽  
Prevention Of Infections

Fungi of the order Mucorales colonize all kinds of wet, organic materials and represent a permanent part of the human environment. They are economically important as fermenting agents of soybean products and producers of enzymes, but also as plant parasites and spoilage organisms. Several taxa cause life-threatening infections, predominantly in patients with impaired immunity. The order Mucorales has now been assigned to the phylum Mucoromycota and is comprised of 261 species in 55 genera. Of these accepted species, 38 have been reported to cause infections in humans, as a clinical entity known as mucormycosis. Due to molecular phylogenetic studies, the taxonomy of the order has changed widely during the last years. Characteristics such as homothallism, the shape of the suspensors, or the formation of sporangiola are shown to be not taxonomically relevant. Several genera including Absidia, Backusella, Circinella, Mucor, and Rhizomucor have been amended and their revisions are summarized in this review. Medically important species that have been affected by recent changes include Lichtheimia corymbifera, Mucor circinelloides, and Rhizopus microsporus. The species concept of Rhizopus arrhizus (syn. R. oryzae) is still a matter of debate. Currently, species identification of the Mucorales is best performed by sequencing of the internal transcribed spacer (ITS) region. Ecologically, the Mucorales represent a diverse group but for the majority of taxa, the ecological role and the geographic distribution remain unknown. Understanding the biology of these opportunistic fungal pathogens is a prerequisite for the prevention of infections, and, consequently, studies on the ecology of the Mucorales are urgently needed.

scholarly journals Dieback and decline pathogens of olive trees in South Africa

2020 ◽  
Vol 45 (1) ◽  
pp. 196-220
Author(s):  
C.F.J. Spies ◽  
L. Mostert ◽  
A. Carlucci ◽  
P. Moyo ◽  
W.J. van Jaarsveld ◽  
...  
Keyword(s):  
South Africa ◽  
New Species ◽  
Fungal Pathogens ◽  
Fungal Species ◽  
Molecular Techniques ◽  
White Rot ◽  
Western Cape ◽  
Production Region ◽  
Wild Olive ◽  
Olive Trees

Trunk disease fungal pathogens reduce olive production globally by causing cankers, dieback, and other decline-related symptoms on olive trees. Very few fungi have been reported in association with olive dieback and decline in South Africa. Many of the fungal species reported from symptomatic olive trees in other countries have broad host ranges and are known to occur on other woody host plants in the Western Cape province, the main olive production region of South Africa. This survey investigated the diversity of fungi and symptoms associated with olive dieback and decline in South Africa. Isolations were made from internal wood symptoms of 145 European and 42 wild olive trees sampled in 10 and 9 districts, respectively. A total of 99 taxa were identified among 440 fungal isolates using combinations of morphological and molecular techniques. A new species of Pseudophaeomoniella, P. globosa, had the highest incidence, being recovered from 42.8 % of European and 54.8 % of wild olive samples. This species was recovered from 9 of the 10 districts where European olive trees were sampled and from all districts where wild olive trees were sampled. Members of the Phaeomoniellales (mainly P. globosa ) were the most prevalent fungi in five of the seven symptom types considered, the only exceptions being twig dieback, where members of the Botryosphaeriaceae were more common, and soft/white rot where only Basidiomycota were recovered. Several of the species identified are known as pathogens of olives or other woody crops either in South Africa or elsewhere in the world, including species of Neofusicoccum, Phaeoacremonium, and Pleurostoma richardsiae. However, 81 of the 99 taxa identified have not previously been recorded on olive trees and have unknown interactions with this host. These taxa include one new genus and several putative new species, of which four are formally described as Celerioriella umnquma sp. nov., Pseudophaeomoniella globosa sp. nov., Vredendaliella oleae gen. & sp. nov., and Xenocylindrosporium margaritarum sp. nov.

scholarly journals Molecular characterisation of fungi associated with sewage-impacted soil

2021 ◽  
Vol 27 (2) ◽  
pp. 107-113
Author(s):  
N. G. Iyanyi ◽  
A. E. Ataga ◽  
E. A Obichi ◽  
S. C. Agbasoga
Keyword(s):  
Pcr Amplification ◽  
Its Region ◽  
Fungal Species ◽  
Molecular Techniques ◽  
Septic Tank ◽  
Nucleotide Sequence Analysis ◽  
Molecular Method ◽  
Base Pairs ◽  
Universal Primer ◽  
Fungal Isolates

The decay of faecal matter from a septic system causes the arousal of fungi in the surrounding soil. These fungi can cause diseases if there is sewage spillage containing untreated or improperly treated wastewaters. Molecular techniques of identification of fungi have shown to be more dependable than traditional methods of identifying fungal species. This study was carried out to identify the fungal species associated with soil obtained from sewage-impacted soil near a septic tank using both traditional cultural techniques and molecular method. Fungi associated with the soil samples were isolated using serial dilution and Potato Dextrose Agar (PDA) method. Deoxyribonucleic Acid (DNA) was extracted from the pure cultures of fungal isolates using Quick DNA Fungal/Bacterial Miniprep kit. Polymerase Chain Reaction (PCR) amplification of internal transcribed spacer (ITS) region of the fungal isolates was carried out using universal primer pair; ITS4 and ITS5. The PCR products were sequenced and the sequences were blasted against National Centre for Biotechnology Information database. The result of the nucleotide sequence analysis revealed the identity of the isolates as Trichoderma harzanium with 580 base pairs and Aspergillus welwitschiae with 560 base pairs. Sequences of the isolates were aligned and compared with sequences on GenBank and a phylogenetic tree was constructed. The cultural method only aided in suggesting the suspected genera of the isolates while the molecular method was able to identify the isolates to the species level. This study will promote the knowledge of the fungal species associated with sewage-impacted soil and also aid researchers in proffering ways to enhance the prevention/control of diseases associated with sewage spill. Keyword: Septic tank, fungi, soil, phylogeny, sequencing

scholarly journals Post-translational regulation of autophagy is involved in intra-microbiome suppression of fungal pathogens

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jing Wang ◽  
Chaoyun Xu ◽  
Qiming Sun ◽  
Jinrong Xu ◽  
Yunrong Chai ◽  
...  
Keyword(s):  
Translational Regulation ◽  
Fungal Pathogens ◽  
Fungal Growth ◽  
Fungal Species ◽  
26S Proteasome ◽  
Healthy Plant ◽  
Autophagy Induction ◽  
Histone Acetyltransferase Gcn5 ◽  
Plant Microbiota ◽  
Autophagic Process

Abstract Background Microbiome interactions are important determinants for ecosystem functioning, stability, and health. In previous studies, it was often observed that bacteria suppress potentially pathogenic fungal species that are part of the same plant microbiota; however, the underlying microbe-microbe interplay remains mostly elusive. Here, we explored antagonistic interactions of the fungus Fusarium graminearum and bacterium Streptomyces hygroscopicus at the molecular level. Both are ubiquitous members of the healthy wheat microbiota; under dysbiosis, the fungus causes devastating diseases. Results In co-cultures, we found that Streptomyces alters the fungal acetylome leading to substantial induction of fungal autophagy. The bacterium secrets rapamycin to inactivate the target of rapamycin (TOR), which subsequently promotes the degradation of the fungal histone acetyltransferase Gcn5 through the 26S proteasome. Gcn5 negatively regulates fungal autophagy by acetylating the autophagy-related protein Atg8 at the lysine site K13 and blocking cellular relocalization of Atg8. Thus, degradation of Gcn5 triggered by rapamycin was found to reduce Atg8 acetylation, resulting in autophagy induction in F. graminearum. Conclusions Autophagy homeostasis plays an essential role in fungal growth and competition, as well as for virulence. Our work reveals a novel post-translational regulation of autophagy initiated by a bacterial antibiotic. Rapamycin was shown to be a powerful modulator of bacteria–fungi interactions with potential importance in explaining microbial homeostasis in healthy plant microbiomes. The autophagic process provides novel possibilities and targets to biologically control pathogens.

scholarly journals Morpho-molecular identification and first report of Fusarium equiseti in causing chilli wilt from Kashmir (Northern Himalayas)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ammarah Hami ◽  
Rovidha S. Rasool ◽  
Nisar A. Khan ◽  
Sheikh Mansoor ◽  
Mudasir A. Mir ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Pcr Amplification ◽  
Its Region ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Kashmir Valley ◽  
Fusarium Equiseti ◽  
Infected Root ◽  
Fusarium Sp ◽  
High Degree

AbstractChilli (Capsicum annuum L.) is one of the most significant vegetable and spice crop. Wilt caused by Fusarium Sp. has emerged as a serious problem in chilli production. Internal transcribed spacer (ITS) region is widely used as a DNA barcoding marker to characterize the diversity and composition of Fusarium communities. ITS regions are heavily used in both molecular methods and ecological studies of fungi, because of its high degree of interspecific variability, conserved primer sites and multiple copy nature in the genome. In the present study we focused on morphological and molecular characterization of pathogen causing chilli wilt. Chilli plants were collected from four districts of Kashmir valley of Himalayan region. Pathogens were isolated from infected root and stem of the plants. Isolated pathogens were subjected to DNA extraction and PCR amplification. The amplified product was sequenced and three different wilt causing fungal isolates were obtained which are reported in the current investigation. In addition to Fusarium oxysporum and Fusarium solani, a new fungal species was found in association with the chilli wilt in Kashmir valley viz., Fusarium equiseti that has never been reported before from this region. The studies were confirmed by pathogenicity test and re-confirmation by DNA barcoding.

scholarly journals Investigation of Antifungal Mechanisms of Thymol in the Human Fungal Pathogen, Cryptococcus neoformans

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3476
Author(s):  
Kwang-Woo Jung ◽  
Moon-Soo Chung ◽  
Hyoung-Woo Bai ◽  
Byung Yeoup Chung ◽  
Sungbeom Lee
Keyword(s):  
Cryptococcus Neoformans ◽  
Fungal Pathogens ◽  
Reverse Genetics ◽  
Mapk Pathway ◽  
Global Climate ◽  
Mitogen Activated Protein Kinase ◽  
Ergosterol Biosynthesis ◽  
Thymus Vulgaris ◽  
Dependent Manner ◽  
Expression Levels

Due to lifespan extension and changes in global climate, the increase in mycoses caused by primary and opportunistic fungal pathogens is now a global concern. Despite increasing attention, limited options are available for the treatment of systematic and invasive mycoses, owing to the evolutionary similarity between humans and fungi. Although plants produce a diversity of chemicals to protect themselves from pathogens, the molecular targets and modes of action of these plant-derived chemicals have not been well characterized. Using a reverse genetics approach, the present study revealed that thymol, a monoterpene alcohol from Thymus vulgaris L., (Lamiaceae), exhibits antifungal activity against Cryptococcus neoformans by regulating multiple signaling pathways including calcineurin, unfolded protein response, and HOG (high-osmolarity glycerol) MAPK (mitogen-activated protein kinase) pathways. Thymol treatment reduced the intracellular concentration of Ca2+ by controlling the expression levels of calcium transporter genes in a calcineurin-dependent manner. We demonstrated that thymol decreased N-glycosylation by regulating the expression levels of genes involved in glycan-mediated post-translational modifications. Furthermore, thymol treatment reduced endogenous ergosterol content by decreasing the expression of ergosterol biosynthesis genes in a HOG MAPK pathway-dependent manner. Collectively, this study sheds light on the antifungal mechanisms of thymol against C. neoformans.

scholarly journals Mitotic Recombination and Adaptive Genomic Changes in Human Pathogenic Fungi

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 901 ◽  
Author(s):  
Asiya Gusa ◽  
Sue Jinks-Robertson
Keyword(s):  
Fungal Pathogens ◽  
Repetitive Sequences ◽  
Pathogenic Fungi ◽  
Genetic Alterations ◽  
Fungal Species ◽  
Chronic Infections ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genomic Changes ◽  
Break Site ◽  
Repair Mechanisms

Genome rearrangements and ploidy alterations are important for adaptive change in the pathogenic fungal species Candida and Cryptococcus, which propagate primarily through clonal, asexual reproduction. These changes can occur during mitotic growth and lead to enhanced virulence, drug resistance, and persistence in chronic infections. Examples of microevolution during the course of infection were described in both human infections and mouse models. Recent discoveries defining the role of sexual, parasexual, and unisexual cycles in the evolution of these pathogenic fungi further expanded our understanding of the diversity found in and between species. During mitotic growth, damage to DNA in the form of double-strand breaks (DSBs) is repaired, and genome integrity is restored by the homologous recombination and non-homologous end-joining pathways. In addition to faithful repair, these pathways can introduce minor sequence alterations at the break site or lead to more extensive genetic alterations that include loss of heterozygosity, inversions, duplications, deletions, and translocations. In particular, the prevalence of repetitive sequences in fungal genomes provides opportunities for structural rearrangements to be generated by non-allelic (ectopic) recombination. In this review, we describe DSB repair mechanisms and the types of resulting genome alterations that were documented in the model yeast Saccharomyces cerevisiae. The relevance of similar recombination events to stress- and drug-related adaptations and in generating species diversity are discussed for the human fungal pathogens Candida albicans and Cryptococcus neoformans.

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