Differential accumulation of fenarimol by a wild-type isolate and fenarimol-resistant isolates of Penicillium italicum

1984 ◽  
Vol 90 (4) ◽  
pp. 143-153 ◽  
Author(s):  
M. A. Waard ◽  
J. G. M. Nistelrooy
Keyword(s):  
Penicillium Italicum ◽  
Wild Type ◽  
Type Isolate

scholarly journals Unveiling the Role Displayed by Penicillium digitatum PdMut3 Transcription Factor in Pathogen–Fruit Interaction

2021 ◽  
Vol 7 (10) ◽  
pp. 828
Author(s):  
Marta de Ramón-Carbonell ◽  
Paloma Sánchez-Torres
Keyword(s):  
Fungal Growth ◽  
Dna Binding Protein ◽  
Invasive Growth ◽  
Wild Type ◽  
Morphological Alterations ◽  
Type Isolate ◽  
In The Wild ◽  
Expression Rate ◽  
Regulatory Functions ◽  
Null Mutants

Zn2Cys6 transcription factors are unique to fungi and are involved in different regulatory functions. In this study, we have identified the Penicillium digitatumPdMut3 gene, which encodes a putative Zn (II) 2Cys6 DNA-binding protein. Elimination of PdMut3 in Pd1 strain caused increased virulence during citrus infection. The transcription of the PdMut3 gene showed a higher expression rate during fungal growth and less transcription during fruit infection. Furthermore, the deletion of the gene in the wild-type isolate of P. digitatum did not produce any modification of the sensitivity to different fungicides, indicating that the gene is not associated with resistance to fungicides. In contrast, PdMut3 null mutants showed a reduction in growth in minimal media, which was associated with severe alterations in conidiophore development and morphological alterations of the hyphae. Mutants showed greater sensitivity to compounds that interfere with the cell wall and an invasive growth block. Thus, PdMut3 might have an indirect role in fungi virulence through metabolism and peroxisomes development.

scholarly journals Mutations in ORP1 Conferring Oxathiapiprolin Resistance Confirmed by Genome Editing using CRISPR/Cas9 in Phytophthora capsici and P. sojae

2018 ◽  
Vol 108 (12) ◽  
pp. 1412-1419 ◽  
Author(s):  
Jianqiang Miao ◽  
Yuandong Chi ◽  
Dong Lin ◽  
Brett M. Tyler ◽  
Xili Liu
Keyword(s):  
Binding Protein ◽  
Phytophthora Capsici ◽  
Control Plant ◽  
Point Mutations ◽  
Wild Type ◽  
Oxysterol Binding Protein ◽  
Type Isolate ◽  
Phytophthora Spp ◽  
Zoospore Production ◽  
Wild Type Parent

Oxathiapiprolin is a novel fungicide that was recently registered in a number of countries to control plant-pathogenic oomycetes such as Phytophthora capsici. In our previous study, point mutations G770V and G839W in oxysterol binding protein-related protein 1 (ORP1) were detected in oxathiapiprolin-resistant P. capsici isolates (PcORP1). Here, we used the CRISPR/Cas9 system to verify the effects of these two point mutations on P. capsici phenotypes. Transformants containing heterozygous G770V and G839W mutations in PcORP1 showed high levels of oxathiapiprolin resistance. The G770V transformants showed otherwise similar phenotypes compared with the wild-type isolate BYA5, including sporangia and zoospore production, cyst germination, and pathogenicity. However, two independent transformants with heterozygous G839W mutations in PcORP1 could not produce sporangia. Three transformants with an unexpected point mutation in PcORP1 (ΔN837) showed high oxathiapiprolin resistance, and either similar or significantly reduced fitness compared with BYA5. The same deletion (ΔN837) was confirmed to confer oxathiapiprolin resistance in P. sojae by using CRISPR/Cas9. These homozygous P. sojae mutants also showed either similar or strongly reduced fitness compared with the wild-type parent isolate P6497. These results improve our understanding of oxathiapiprolin resistance in Phytophthora spp., and will be useful for the development of novel oxysterol-binding protein homolog inhibitor fungicides.

scholarly journals VibA, a Homologue of a Transcription Factor for Fungal Heterokaryon Incompatibility, Is Involved in Antifungal Compound Production in the Plant-Symbiotic Fungus Epichloë festucae

2014 ◽  
Vol 14 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Jennifer T. Niones ◽  
Daigo Takemoto
Keyword(s):  
Transcription Factor ◽  
Antifungal Activity ◽  
Critical Role ◽  
Antifungal Compound ◽  
Symbiotic Association ◽  
Wild Type ◽  
Exogenous Dna ◽  
Content Type ◽  
Type Isolate ◽  
Epichloë Festucae

ABSTRACT Symbiotic association of epichloae endophytes ( Epichloë/Neotyphodium species) with cool-season grasses of the subfamily Pooideae confers bioprotective benefits to the host plants against abiotic and biotic stresses. While the production of fungal bioprotective metabolites is a well-studied mechanism of host protection from insect herbivory, little is known about the antibiosis mechanism against grass pathogens by the mutualistic endophyte. In this study, an Epichloë festucae mutant defective in antimicrobial substance production was isolated by a mutagenesis approach. In an isolated mutant that had lost antifungal activity, the exogenous DNA fragment was integrated into the promoter region of the vibA gene, encoding a homologue of the transcription factor VIB-1. VIB-1 in Neurospora crassa is a regulator of genes essential in vegetative incompatibility and promotion of cell death. Here we show that deletion of the vibA gene severely affected the antifungal activity of the mutant against the test pathogen Drechslera erythrospila . Further analyses showed that overexpressing vibA enhanced the antifungal activity of the wild-type isolate against test pathogens. Transformants overexpressing vibA showed an inhibitory activity on test pathogens that the wild-type isolate could not. Moreover, overexpressing vibA in a nonantifungal E. festucae wild-type Fl1 isolate enabled the transformant to inhibit the mycelial and spore germination of D. erythrospila . These results demonstrate that enhanced expression of vibA is sufficient for a nonantifungal isolate to obtain antifungal activity, implicating the critical role of VibA in antifungal compound production by epichloae endophytes.

scholarly journals Phytophthora capsici sterol reductase PcDHCR7 has a role in mycelium development and pathogenicity

2021 ◽  
Author(s):  
Weizhen Wang ◽  
Fan Zhang ◽  
Sicong Zhang ◽  
Zhaolin Xue ◽  
Linfang Xie ◽  
...  
Keyword(s):  
De Novo ◽  
Reductase Activity ◽  
Phytophthora Capsici ◽  
Biosynthesis Pathway ◽  
Wild Type ◽  
Knock Out ◽  
Type Isolate ◽  
De Novo Biosynthesis ◽  
Phytophthora Spp ◽  
Genes Encoding

The de novo biosynthesis of sterols is critical for eukaryotes, however, some organisms lack this pathway including most oomycetes. Phytophthora spp. are sterol auxotroph but remarkably, have retained a few genes encoding enzymes in the sterol biosynthesis pathway. Here we investigated the function of PcDHCR7, a gene in Phytophthora capsici predicted to encode the Δ7-sterol reductase. When expressed in Saccharomyces cerevisiae, PcDHCR7 showed a Δ7-sterol reductase activity. Knocking out PcDHCR7 in P. capsici resulted in loss of the capacity to transform ergosterol into brassicasterol, which means PcDHCR7 has a Δ7-sterol reductase activity in P. capsici itself. This enables P. capsici to transform sterols recruited from the environment for better use. Biological characteristics were compared between wild-type isolate and PcDHCR7 knock-out transformants. The results indicated that PcDHCR7 plays a key role in mycelium development and pathogenicity of zoospores in P. capsici.

scholarly journals Complete Genome Sequence of a Wild-Type Isolate of Caulobacter vibrioides Strain CB1

2018 ◽  
Vol 7 (12) ◽  
Author(s):  
Derrick C. Scott ◽  
Kiesha Wilson ◽  
Keshawn Ross ◽  
Damyen Ingram ◽  
Tajah Lewter ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Dna Sequences ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Genome Rearrangement ◽  
Gc Content ◽  
Wild Type ◽  
Content Type ◽  
Type Isolate

The complete genome sequence of Caulobacter vibrioides strain CB1 consists of a chromosome of 4,137,285 bp, with a GC content of 67.2% and 3,990 coding DNA sequences. This strain contains the typical genome rearrangement that is characteristic of the Caulobacter strains that are currently sequenced.

Ultrastructure of Melanin Formation in Thielaviopsis Basicola

1976 ◽  
Vol 34 ◽  
pp. 50-51
Author(s):  
M. H. Wheeler ◽  
W. J. Tolmsoff ◽  
A. A. Bell ◽  
R. D. Stipanovic
Keyword(s):  
Agar Medium ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Transmission Microscopy ◽  
Electron Transmission ◽  
Type Isolate ◽  
Melanin Formation ◽  
Albino Mutant ◽  
Before And After ◽  
Electron Transmission Microscopy

Melanin formation in the fungus Thielaviopsis basicola was examined by light and electron-transmission microscopy with methods described previously in studies of Verticillium dahliae (1,2). A wild-type isolate and an albino mutant of T. basicola were grown on potato-carrot-dextrose-agar medium at 24°C prior to chemical treatment. The wild-type isolate was examined and compared with the albino mutant before and after treatment with each of the following compounds that have been proposed as melanin intermediates in various fungi (3): (+)-scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2H)- naphthalenone]; 1,8-dihydroxynaphthalene (DHN); L-3,4-dihydroxyphenylalanine (DOPA); and catechol.

scholarly journals Isolation of Nonpathogenic Mutants of Fusarium oxysporum f. sp. melonis for Biological Control of Fusarium Wilt in Cucurbits

2002 ◽  
Vol 92 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Stanley Freeman ◽  
Aida Zveibil ◽  
Haim Vintal ◽  
Marcel Maymon
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Fungal Pathogens ◽  
Conidial Suspension ◽  
Wild Type ◽  
Seedling Mortality ◽  
Type Isolate ◽  
Novel Approach ◽  
Mutant Strains ◽  
Race 2

Two nonpathogenic mutant strains 4/4 and 15/15 of Fusarium oxysporum f. sp. melonis (race 1,2) were isolated by a continuous dipinoculation technique following UV mutagenesis of the virulent wild-type isolate FOM1.2. No disease symptoms or detrimental effects were observed following inoculation of muskmelon seedlings by strain 4/4. In contrast, strain 15/15 caused mortality of susceptible cultivars although to a lesser extent than the wild-type isolate. Strain 4/4 colonized a variety of muskmelon and watermelon cultivars. In muskmelon cv. Ein Dor, seedlings were dipped in a conidial suspension of strain 4/4 and planted in medium amended with the mutant to achieve 100% colonization of roots and between 30 to 70% of the lower stem tissues 7 days after planting. Similar percent colonization of watermelon seedlings by strain 4/4 was recorded. In cross-protection experiments with muskmelon cultivars, significant reduction in seedling mortality was observed between 4/4-colonized FOM1.2. challenged plants compared with that of wild-type challenged plants alone. Similarly, strain 4/4 was able to significantly reduce mortality of watermelon seedlings caused by F. oxysporum f. sp. niveum race 2. This novel approach of generating nonpathogenic mutants for biological control in Fusarium spp. and other fungal pathogens from virulent wild-type isolates may be beneficial for control, because the mutant strains, lacking only in pathogenicity, may compete more efficiently than other biocontrol organisms against the pathogen of origin.

An endophytic chitinase-producing isolate of Actinoplanes missouriensis, with potential for biological control of root rot of lupin caused by Plectosporium tabacinum

2003 ◽  
Vol 51 (3) ◽  
pp. 257 ◽  
Author(s):  
Khaled A. El-Tarabily
Keyword(s):  
Biological Control ◽  
Cell Wall ◽  
Root Rot ◽  
Germ Tube ◽  
First Record ◽  
Plant Roots ◽  
Wild Type ◽  
Type Isolate ◽  
Cell Wall Lysis

Twenty-one streptomycete and 15 non-streptomycete actinomycetes were isolated from surface-disinfested lupin roots and evaluated for their potential to produce chitinase and to inhibit the growth of Plectosporium tabacinum, the causal agent of lupin root rot in Egypt. The most inhibitory isolate was identified as Actinoplanes missouriensis which produced relatively high levels of chitinase and degraded the hyphae of P.�tabacinum in vitro, causing extensive plasmolysis and cell-wall lysis. A crude culture filtrate of A. missouriensis exhibited antifungal activity and significantly (P < 0.05) reduced spore germination and germ-tube growth of the pathogen. The antagonist was recovered from inside the root at all samplings up to 8 weeks after inoculation, indicating that the roots of healthy lupin may be a habitat for the endophyte. A. missouriensis significantly (P < 0.05) reduced the severity of root rot under glasshouse conditions. An endophytic isolate of Actinoplanes italicus incapable of producing chitinase and a mutant strain of A. missouriensis that did not produce detectable levels of chitinase, did not lyse hyphae of P. tabacinum or reduce root rot in the glasshouse experiments, although colonisation of the lupin root by both these isolates was similar to that of the chitinase-producing wild-type isolate of A. missouriensis. This study is the first record of control of a soil-borne plant pathogen by a chitinolytic actinomycete, endophytic in plant roots.

scholarly journals Multinuclei Occurred Under Cryopreservation and Enhanced the Pathogenicity of Melampsora larici-populina

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Zheng ◽  
Zijia Peng ◽  
Shaobing Peng ◽  
Zhongdong Yu ◽  
Zhimin Cao
Keyword(s):  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Gas Chromatography Mass Spectrometry ◽  
Blue Staining ◽  
Wild Type ◽  
Qrt Pcr ◽  
Type Isolate ◽  
Multiple Nucleus ◽  
Mitogen Activated Protein ◽  
Fatty Acids Metabolism

Melampsora larici-populina is a macrocyclic rust, and the haploid stage with two nuclei and the diploid of mononuclear sequentially occur annually. During the preservation of dry urediniospores at −80°C, we found that one isolate, ΔTs06, was different from the usual wild-type isolate Ts06 at −20°C because it has mixed polykaryotic urediniospores. However, the other spores, including the 0, I, III, and IV stages of a life cycle, were the same as Ts06. After five generations of successive inoculation and harvest of urediniospores from the compatible host Populus purdomii, the isolate ΔTs06 steadily maintained more than 20% multiple nucleus spores. To test the pathogenesis variation of ΔTs06, an assay of host poplars was applied to evaluate the differences between ΔTs06 and Ts06. After ΔTs06 and Ts06 inoculation, leaves of P. purdomii were used to detect the expression of small secreted proteins (SSPs) and fungal biomasses using quantitative real-time PCR (qRT-PCR) and trypan blue staining. ΔTs06 displayed stronger expression of five SSPs and had a shorter latent period, a higher density of uredinia, and higher DNA mass. A transcriptomic comparison between ΔTs06 and Ts06 revealed that 3,224 were differentially expressed genes (DEGs), 55 of which were related to reactive oxygen species metabolism, the Mitogen-activated protein kinase (MAPK) signaling pathway, and the meiosis pathway. Ten genes in the mitotic and meiotic pathways and another two genes associated with the “response to DNA damage stimulus” all had an upward expression, which were detected by qRT-PCR in ΔTs06 during cryopreservation. Gas chromatography–mass spectrometry (GC-MS) confirmed that the amounts of hexadecanoic acid and octadecadienoic acid were much more in ΔTs06 than in Ts06. In addition, using spectrophotometry, hydrogen peroxide (H2O2) was also present in greater quantities in ΔTs06 compared with those found in Ts06. Increased fatty acids metabolism could prevent damage to urediniospores in super-low temperatures, but oxidant species that involved H2O2 may destroy tube proteins of mitosis and meiosis, which could cause abnormal nuclear division and lead to multinucleation, which has a different genotype. Therefore, the multinuclear isolate is different from the wild-type isolate in terms of phenotype and genotype; this multinucleation phenomenon in urediniospores improves the pathogenesis and environmental fitness of M. larici-populina.

scholarly journals Inheritance of extrachromosomal ribosomal DNA during the asexual life cycle of Dictyostelium discoideum: examination by use of DNA polymorphisms.

1985 ◽  
Vol 5 (2) ◽  
pp. 273-280 ◽  
Author(s):  
D L Welker ◽  
K P Hirth ◽  
K L Williams
Keyword(s):  
Life Cycle ◽  
Dictyostelium Discoideum ◽  
Ribosomal Dna ◽  
Dna Polymorphisms ◽  
Haploid Cell ◽  
Wild Type ◽  
Parasexual Cycle ◽  
Restriction Fragments ◽  
Type Isolate ◽  
Ca 50

Wild-type isolates of Dictyostelium discoideum exhibited differences in the size of restriction fragments of the extrachromosomal 88-kilobase ribosomal DNA (rDNA) palindrome. Polymorphisms in rDNA also were found among strains derived solely from the NC4 wild-type isolate. These variations involved EcoRI fragments II, III, and V; they included loss of the EcoRI site separating fragments II and V and deletion and insertion of DNA. More than one rDNA form can coexist in the same diploid or haploid cell. However, one or another parental rDNA tended to predominate in diploids constructed, using the parasexual cycle, between haploid NC4-derived strains and haploid wild-type isolates. In some cases, most if not all of the rDNA of such diploids were of one form after ca. 50 generations of growth. Segregant haploids, derived from diploids that possessed predominantly a single rDNA allele, possessed the same allele as the diploid and did not recover the other form. This evidence implies that replication does not proceed from a single chromosomal or extrachromosomal copy of the rDNA during the asexual life cycle of D. discoideum.

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