MyMedR

Displaying all 10 publications

Abstract:

Sort:

Fulltext Host specialization and phylogenetic diversity of Corynespora cassiicola

Dixon LJ, Schlub RL, Pernezny K, Datnoff LE

Phytopathology, 2009 Sep;99(9):1015-27.
PMID: 19671003 DOI: 10.1094/PHYTO-99-9-1015

The fungus Corynespora cassiicola is primarily found in the tropics and subtropics, and is widely diverse in substrate utilization and host association. Isolate characterization within C. cassiicola was undertaken to investigate how genetic diversity correlates with host specificity, growth rate, and geographic distribution. C. cassiicola isolates were collected from 68 different plant species in American Samoa, Brazil, Malaysia, and Micronesia, and Florida, Mississippi, and Tennessee within the United States. Phylogenetic analyses using four loci were performed with 143 Corynespora spp. isolates, including outgroup taxa obtained from culture collections: C. citricola, C. melongenae, C. olivacea, C. proliferata, C. sesamum, and C. smithii. Phylogenetic trees were congruent from the ribosomal DNA internal transcribed spacer region, two random hypervariable loci (caa5 and ga4), and the actin-encoding locus act1, indicating a lack of recombination within the species and asexual propagation. Fifty isolates were tested for pathogenicity on eight known C. cassiicola crop hosts: basil, bean, cowpea, cucumber, papaya, soybean, sweet potato, and tomato. Pathogenicity profiles ranged from one to four hosts, with cucumber appearing in 14 of the 16 profiles. Bootstrap analyses and Bayesian posterior probability values identified six statistically significant phylogenetic lineages. The six phylogenetic lineages correlated with host of origin, pathogenicity, and growth rate but not with geographic location. Common fungal genotypes were widely distributed geographically, indicating long-distance and global dispersal of clonal lineages. This research reveals an abundance of previously unrecognized genetic diversity within the species and provides evidence for host specialization on papaya.

Matched MeSH terms: Ascomycota/classification*
New species of Stigmatomyces from various continents

Rossi W, Weir A

Mycologia, 2007 8 1;99(1):139-43.
PMID: 17663133

Four new species of Stigmatomyces (Ascomycetes, Laboulbeniales, Stigmatomycetinae) parasitic on flies (Diptera) are described. These are S. benjaminii, parasitic on Spilochroa polita (Trixoscelididae) from Mexico, S. munarii, parasitic on Trixoscelis namibensis (Trixoscelididae) from Namibia, S. neurochaetae parasitic on Neurochaeta parviceps (Neurochaetidae) from Malaysia, and S. zaleae, parasitic on Zalea spp. (Tethinidae) from Australia. Both Trixoscelididae and Neurochaetidae are new host families for Laboulbeniales.

Matched MeSH terms: Ascomycota/classification*
Isolation of keratinophilic fungi from soil in Malaysia

Soon SH

Mycopathologia, 1991 Mar;113(3):155-8.
PMID: 2067562

Two hundred and thirty soil samples from different localities were examined for the presence of geophilic keratinophilic fungi. Six species namely Microsporum gypseum--34 isolates, Chrysosporium keratinophilum--29, C. tropicum--20, Keratinophyton terreum--4, Trichophyton terrestre--8 and Chrysosporium species--3--were isolated. Most of these fungi were recovered from garden, field and river bank soil. The importance of these findings is briefly discussed.

Matched MeSH terms: Ascomycota/classification
Morphological and Inter Simple Sequence Repeat (ISSR) markers analyses of Corynespora cassiicola isolates from rubber plantations in Malaysia

Nghia NA, Kadir J, Sunderasan E, Puad Abdullah M, Malik A, Napis S

Mycopathologia, 2008 Oct;166(4):189-201.
PMID: 18568417 DOI: 10.1007/s11046-008-9138-8

Morphological features and Inter Simple Sequence Repeat (ISSR) polymorphism were employed to analyse 21 Corynespora cassiicola isolates obtained from a number of Hevea clones grown in rubber plantations in Malaysia. The C. cassiicola isolates used in this study were collected from several states in Malaysia from 1998 to 2005. The morphology of the isolates was characteristic of that previously described for C. cassiicola. Variations in colony and conidial morphology were observed not only among isolates but also within a single isolate with no inclination to either clonal or geographical origin of the isolates. ISSR analysis delineated the isolates into two distinct clusters. The dendrogram created from UPGMA analysis based on Nei and Li's coefficient (calculated from the binary matrix data of 106 amplified DNA bands generated from 8 ISSR primers) showed that cluster 1 encompasses 12 isolates from the states of Johor and Selangor (this cluster was further split into 2 sub clusters (1A, 1B), sub cluster 1B consists of a unique isolate, CKT05D); while cluster 2 comprises of 9 isolates that were obtained from the other states. Detached leaf assay performed on selected Hevea clones showed that the pathogenicity of representative isolates from cluster 1 (with the exception of CKT05D) resembled that of race 1; and isolates in cluster 2 showed pathogenicity similar to race 2 of the fungus that was previously identified in Malaysia. The isolate CKT05D from sub cluster 1B showed pathogenicity dissimilar to either race 1 or race 2.

Matched MeSH terms: Ascomycota/classification
Identification of Botryosphaeriaceae associated with stem-end rot of mango (Mangifera indica L.) in Malaysia

Li L, Mohd MH, Mohamed Nor NMI, Subramaniam S, Latiffah Z

J Appl Microbiol, 2021 Apr;130(4):1273-1284.
PMID: 32813902 DOI: 10.1111/jam.14828

AIMS: To identify Botryosphaeriaceae fungal species that are associated with stem-end rot of mango, and to study their pathogenicity on mango fruit.
METHODS AND RESULTS: Based on the sequences of internal transcribed spacer (ITS), TEF1-α and β-tubulin, as well as on the phylogenetic analysis of combined sequences, four species of Lasiodiplodia (L. theobromae,L. pseudotheobromae, L. iranensis, L. mahajangana) and two species of Neofusicoccum (N. ribis, N. parvum) were identified. Pseudofusicoccum violaceum, Neoscytalidium dimidiatum and three species of Botryosphaeria (B. scharifii, B. dothidea, B. ramosa) were identified based on sequences of ITS and TEF1-α. Pathogenicity test of selected isolates were tested on Chok Anan, Waterlily and Falan mango cultivars. Generally, all species were observed to be pathogenic on the three tested mango cultivars on wounded fruits, except for N. ribis and N. parvum, which were pathogenic on both wounded and unwounded fruits. However, N. ribis was only pathogenic on cultivar Falan, whereas B. ramosa were pathogenic on cultivars Waterlily and Falan.
CONCLUSIONS: Eleven species of Botryosphaeriaceae were associated with mango stem-end rot in Malaysia. To the best of our knowledge, four species, namely L. mahajangana, B. ramosa, N. ribis and P. violaceum are the first recorded Botryosphaeriaceae fungi associated with stem end rot of mango.
SIGNIFICANCE AND IMPACT OF THE STUDY: The identification of Botryosphaeriaceae fungi is important to establish suitable control measures and quarantine requirements. Many species have a wide host range, which means that there is a possibility of cross infection from other infected plants.

Matched MeSH terms: Ascomycota/classification
Fulltext Genome sequence of an unclassified pleosporales species isolated from human nasopharyngeal aspirate

Ng KP, Yew SM, Chan CL, Soo-Hoo TS, Na SL, Hassan H, et al.

Eukaryot Cell, 2012 Jun;11(6):828.
PMID: 22645233 DOI: 10.1128/EC.00133-12

Pleosporales is the largest order in the fungal class Dothideomycetes. We report the 36,814,818-bp draft genome sequence and gene annotation of UM1110, a Pleosporales isolate associated with unclassified genera that is potentially a new fungal species. Analysis of the genome sequence led to the finding of genes associated with fungal adhesive proteins, secreted proteases, allergens, and pseudohyphal development.

Matched MeSH terms: Ascomycota/classification
Fulltext The genome of newly classified Ochroconis mirabilis: Insights into fungal adaptation to different living conditions

Yew SM, Chan CL, Kuan CS, Toh YF, Ngeow YF, Na SL, et al.

BMC Genomics, 2016 Feb 03;17:91.
PMID: 26842951 DOI: 10.1186/s12864-016-2409-8

Ochroconis mirabilis, a recently introduced water-borne dematiaceous fungus, is occasionally isolated from human skin lesions and nails. We identified an isolate of O. mirabilis from a skin scraping with morphological and molecular studies. Its genome was then sequenced and analysed for genetic features related to classification and biological characteristics.

Matched MeSH terms: Ascomycota/classification*
Fulltext Genomic Analyses of Cladophialophora bantiana, a Major Cause of Cerebral Phaeohyphomycosis Provides Insight into Its Lifestyle, Virulence and Adaption in Host

Kuan CS, Cham CY, Singh G, Yew SM, Tan YC, Chong PS, et al.

PLoS One, 2016;11(8):e0161008.
PMID: 27570972 DOI: 10.1371/journal.pone.0161008

Cladophialophora bantiana is a dematiaceous fungus with a predilection for causing central nervous system (CNS) infection manifesting as brain abscess in both immunocompetent and immunocompromised patients. In this paper, we report comprehensive genomic analyses of C. bantiana isolated from the brain abscess of an immunocompetent man, the first reported case in Malaysia and Southeast Asia. The identity of the fungus was determined using combined morphological analysis and multilocus phylogeny. The draft genome sequence of a neurotrophic fungus, C. bantiana UM 956 was generated using Illumina sequencing technology to dissect its genetic fundamental and basic biology. The assembled 37.1 Mb genome encodes 12,155 putative coding genes, of which, 1.01% are predicted transposable elements. Its genomic features support its saprophytic lifestyle, renowned for its versatility in decomposing hemicellulose and pectin components. The C. bantiana UM 956 was also found to carry some important putative genes that engaged in pathogenicity, iron uptake and homeostasis as well as adaptation to various stresses to enable the organism to survive in hostile microenvironment. This wealth of resource will further catalyse more downstream functional studies to provide better understanding on how this fungus can be a successful and persistent pathogen in human.

Matched MeSH terms: Ascomycota/classification
Fulltext Functional expression of a novel α-amylase from Antarctic psychrotolerant fungus for baking industry and its magnetic immobilization

He L, Mao Y, Zhang L, Wang H, Alias SA, Gao B, et al.

BMC Biotechnol, 2017 02 28;17(1):22.
PMID: 28245836 DOI: 10.1186/s12896-017-0343-8

BACKGROUND: α-Amylase plays a pivotal role in a broad range of industrial processes. To meet increasing demands of biocatalytic tasks, considerable efforts have been made to isolate enzymes produced by extremophiles. However, the relevant data of α-amylases from cold-adapted fungi are still insufficient. In addition, bread quality presents a particular interest due to its high consummation. Thus developing amylases to improve textural properties could combine health benefits with good sensory properties. Furthermore, iron oxide nanoparticles provide an economical and convenient method for separation of biomacromolecules. In order to maximize the catalytic efficiency of α-amylase and support further applications, a comprehensive characterization of magnetic immobilization of α-amylase is crucial and needed.
RESULTS: A novel α-amylase (AmyA1) containing an open reading frame of 1482 bp was cloned from Antarctic psychrotolerant fungus G. pannorum and then expressed in the newly constructed Aspergillus oryzae system. The purified recombinant AmyA1 was approximate 52 kDa. AmyA1 was optimally active at pH 5.0 and 40 °C, and retained over 20% of maximal activity at 0-20 °C. The K m and V max values toward soluble starch were 2.51 mg/mL and 8.24 × 10-2 mg/(mL min) respectively, with specific activity of 12.8 × 103 U/mg. AmyA1 presented broad substrate specificity, and the main hydrolysis products were glucose, maltose, and maltotetraose. The influence of AmyA1 on the quality of bread was further investigated. The application study shows a 26% increase in specific volume, 14.5% increase in cohesiveness and 14.1% decrease in gumminess in comparison with the control. AmyA1 was immobilized on magnetic nanoparticles and characterized. The immobilized enzyme showed improved thermostability and enhanced pH tolerance under neutral conditions. Also, magnetically immobilized AmyA1 can be easily recovered and reused for maximum utilization.
CONCLUSIONS: A novel α-amylase (AmyA1) from Antarctic psychrotolerant fungus was cloned, heterologous expression in Aspergillus oryzae, and characterized. The detailed report of the enzymatic properties of AmyA1 gives new insights into fungal cold-adapted amylase. Application study showed potential value of AmyA1 in the food and starch fields. In addition, AmyA1 was immobilized on magnetic nanoparticles and characterized. The improved stability and longer service life of AmyA1 could potentially benefit industrial applications.

Matched MeSH terms: Ascomycota/classification
Morphological and molecular characterization, sexual reproduction, and pathogenicity of Setosphaeria rostrata isolates from rice leaf spot

Kusai NA, Azmi MM, Zainudin NA, Yusof MT, Razak AA

Mycologia, 2016 09;108(5):905-914.
PMID: 27474518

Setosphaeria rostrata, a common plant pathogen causing leaf spot disease, affects a wide range of plant species, mainly grasses. Fungi were isolated from brown spots on rice leaves throughout Peninsular Malaysia, and 45 isolates were identified as Setosphaeria rostrata The isolates were then characterized using morphological and molecular approaches. The mating type was determined using PCR amplification of the mating type alleles, and isolates of opposite mating types were crossed to examine sexual reproduction. Based on nuclear ribosomal DNA ITS1-5.8S-ITS2 region (ITS) and beta-tubulin (BT2) sequences, two phylogenetic trees were constructed using the maximum likelihood method; S. rostrata was clustered in one well-supported clade. Pathogenicity tests showed that S. rostrata isolates are pathogenic, suggesting that it is the cause of the symptoms. Mating-type analyses indicated that three isolates carried the MAT1-1 allele, and the other 42 isolates carried MAT1-2 After isolates with opposite mating types were crossed on Sach's medium and incubated for 3 wk, six crosses produced pseudothecia that contained eight mature ascospores, and 12 other crosses produced numerous pseudothecia with no ascospores. To our knowledge, this is the first report on S. rostrata isolated from leaf spots on rice.

Matched MeSH terms: Ascomycota/classification*