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EFSA Journal. European Food Safety... Dec 2023Following an EFSA commodity risk assessment of bonsai plants ( grafted on ) imported from China, the EFSA Plant Health Panel performed a pest categorisation of a...
Following an EFSA commodity risk assessment of bonsai plants ( grafted on ) imported from China, the EFSA Plant Health Panel performed a pest categorisation of a clearly defined plant pathogenic fungus of the family Pestalotiopsidaceae. The pathogen was reported on a wide range of monocotyledonous, dicotyledonous and gymnosperms, either cultivated or wild plant species, causing various symptoms such as leaf spot, leaf blight, scabby canker, fruit spot, pre- and post-harvest fruit rot and root rot. In addition, the fungus was reported as an endophyte on a wide range of asymptomatic plant species. This pest categorisation focuses on the hosts that are relevant for the EU and for which there is robust evidence that the pathogen was formally identified by a combination of morphology, pathogenicity and multilocus sequencing analyses. was reported in Africa, North, Central and South America, Asia and Oceania. In the EU, it was reported in the Netherlands. There is a key uncertainty on the geographical distribution of worldwide and in the EU, because of the endophytic nature of the fungus, the lack of surveys, and because in the past, when molecular tools were not fully developed, the pathogen might have been misidentified as other species or other members of the Pestalodiopsidaceae family based on morphology and pathogenicity tests. is not included in Commission Implementing Regulation (EU) 2019/2072. Plants for planting, fresh fruits, bark and wood of host plants as well as soil and other growing media associated with plant debris are the main pathways for the entry of the pathogen into the EU. Host availability and climate suitability in parts of the EU are favourable for the establishment and spread of the pathogen. The introduction and spread of the pathogen into the EU are expected to have an economic and environmental impact where susceptible hosts are grown. Phytosanitary measures are available to prevent the introduction and spread of the pathogen into the EU. Unless the restricted distribution in the EU is disproven, satisfies all the criteria that are within the remit of EFSA to assess for this species to be regarded as potential Union quarantine pest.
PubMed: 38130321
DOI: 10.2903/j.efsa.2023.8493 -
EFSA Journal. European Food Safety... Dec 2023Following the commodity risk assessments of bonsai plants from China consisting of grafted on performed by EFSA, the EFSA Plant Health Panel performed a pest...
Following the commodity risk assessments of bonsai plants from China consisting of grafted on performed by EFSA, the EFSA Plant Health Panel performed a pest categorisation of a clearly defined plant pathogenic fungus of the family Pestalotiopsidaceae. The pathogen has been reported on herbaceous, woody and ornamental plants causing symptoms such as leaf blight, shoot blight, seedling blight, pod canker, pre- and post-harvest fruit rot, and gummosis. Moreover, the fungus was reported as an endophyte on a wide range of asymptomatic hosts. The pathogen is present in Africa, North and South America, Asia, Europe and Oceania. It has been reported from the EU, with a restricted distribution (Portugal). There is a key uncertainty on the geographical distribution of in the EU and worldwide, because of the endophytic nature of the fungus, the lack of surveys and since the pathogen might have been misidentified based only on morphology and pathogenicity tests. The pathogen is not included in Commission Implementing Regulation (EU) 2019/2072. This pest categorisation focuses on those hosts that are relevant for the EU and for which there is robust evidence that the pathogen was formally identified by a combination of morphology, pathogenicity and multilocus sequence analysis. Plants for planting, fresh fruits, bark and wood of host plants as well as soil and other plant growing media are the main pathways for the entry of the pathogen into the EU. Host availability and climate suitability factors occurring in parts of the EU are favourable for the establishment of the pathogen. Despite the low aggressiveness observed in most reported hosts, and the fact that may colonise plants as an endophyte, its introduction and spread in the EU may have an economic and environmental impact (with a key uncertainty) where susceptible hosts are grown. Phytosanitary measures are available to prevent the introduction and spread of the pathogen. The Panel cannot conclude on whether satisfies all the criteria that are within the remit of EFSA to assess for this species to be regarded as potential Union quarantine pest, because of the key uncertainties on the restricted distribution in the EU and the magnitude of the impact.
PubMed: 38116101
DOI: 10.2903/j.efsa.2023.8494 -
Polish Journal of Microbiology Dec 2023The sp. strain cr013 is a mycoparasite of , a potential biocontrol fungus for Armand pine () blister rust. A previous study showed that the strain cr013 has great...
The sp. strain cr013 is a mycoparasite of , a potential biocontrol fungus for Armand pine () blister rust. A previous study showed that the strain cr013 has great potential to produce new compounds. However, there has been no report of the whole-genome sequence of the mycoparasite sp. In this study, the BGISEQ-500 and Oxford Nanopore GridION X5 sequencing platforms were used to sequence the strain cr013 isolates and assemble the reads to obtain the complete genome. We first report the whole-genome information of the mycoparasite sp. strain cr013 (GenBank accession number: JACFXT010000000, BioProject ID: PRJNA647543, BioSample ID: SAMN15589943), and the genomic components and gene functions related to the mycoparasitism process were analyzed. This study provides a theoretical basis for understanding the lifestyle strategy of the mycoparasite sp. and reveals the mechanisms underlying secondary metabolite diversity in the strain cr013.
Topics: Pestalotiopsis; Basidiomycota; Genomics; Fungi
PubMed: 38095159
DOI: 10.33073/pjm-2023-041 -
Biocontrol fungi induced stem-base rot disease resistance of How revealed by transcriptome analysis.Frontiers in Microbiology 2023How (MO) is a Rubiaceae plant, and its medicinal part is dried root, which is one of the "Four Southern Medicines" in China. At present, the plant MO breed seedlings...
INTRODUCTION
How (MO) is a Rubiaceae plant, and its medicinal part is dried root, which is one of the "Four Southern Medicines" in China. At present, the plant MO breed seedlings mainly by cutting methods. Long-term asexual propagation makes pathogenic fungi accumulate in MO, leading to stem-base rot, which is caused by (Fon).
METHODS
In this study, we used and sp. as biocontrol fungi to investigate their antagonistic ability to Fon through in vitro antagonism and pot experiments, and combined with transcriptome sequencing to explore the mechanism of biocontrol.
RESULTS
The results showed that both and sp. could inhibit the growth of Fon. In addition, and sp. could also enhance the basic immunity to Fon by increasing the activities of defensive enzymes such as POD and SOD, chlorophyll content, soluble sugar content, and oligosaccharide content of MO. The mechanism of biological control of stem-base rot of MO was discussed by transcriptome technology. MO was treated with two treatments, root irrigation with biocontrol fungi or inoculation with Fon after root irrigation with biocontrol fungi. Transcriptome sequencing revealed that nearly 11,188 differentially expressed genes (DEGs) were involved in the process of inducing MO systemic resistance to Fon by biocontrol fungi. Meanwhile, Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, as well as transcription factor (TFs) prediction showed that there were significant differences in the expression levels of MO roots under different treatments. Also, the genes of the "MAPK signaling pathway" and "plant hormone signaling pathway" were analyzed, in which the ERFs gene of the ethylene signal transduction pathway participated in the metabolism of glycosyl compounds. It is speculated that the ethylene signal may participate in the immune response of the sugar signal to the infection of Fon. After qRT-PCR verification of 10 DEGs related to the ethylene signal transduction pathway, the expression trend is consistent with the results of transcriptome sequencing, which proves the reliability of transcriptome sequencing.
DISCUSSION
In conclusion, this study preliminarily identified the molecular mechanism of the biological control of MO stem-base rot and provided a scientific basis for further research on the prevention and control mechanism of MO stem-base rot.
PubMed: 38107850
DOI: 10.3389/fmicb.2023.1257437 -
Pathogens (Basel, Switzerland) Nov 2023The main pathogens affecting the carob () tree in the Mediterranean basin are described in this overview. The most widespread diseases periodically occurring in carob... (Review)
Review
The main pathogens affecting the carob () tree in the Mediterranean basin are described in this overview. The most widespread diseases periodically occurring in carob orchards are powdery mildew () and cercospora leaf spot (). The causal agents of "black leaf spots" (e.g., , and spp.) are responsible for symptoms similar to those previously mentioned for foliar diseases, but are reported in carob orchards at a negligible frequency. Likewise, canker and branch diebacks caused by fungal species belonging to Botryosphaeriaceae are almost never recorded. Among the rots of wood tissues that may compromise old carob specimens, "brown cubical rot" caused by is the most widespread and recurrent issue; this pathogen is also well-known for producing edible fruit bodies that are appreciated for pharmaceutical and industrial purposes. On the other hand, "white rots" caused by and species are less common and reported for the first time in this review. Gall-like protuberances on twigs of uncertain aetiology or tumors on branches associated with are described, although these symptoms are seldom detected, as they are also observed for necrotic leaf spots caused by pv. . A worldwide list of pathogens not yet recorded but at high risk of potential introduction in Italian carob-producing areas is also provided. Finally, concerns related to new phytopathogenic fungi vectored by the invasive ambrosia beetle are addressed. All the described pathogens could become limiting factors for carob production in the near future, because they could be favored by high-density orchards, the increasing global network of trade exchanges, and the high frequency at which extreme events related to climate change occur globally. Thus, symptoms and signs, causal agents, epidemiology, and, whenever applicable, recommendations for disease prevention and management are provided in this review.
PubMed: 38003821
DOI: 10.3390/pathogens12111357 -
MycoKeys 2024, commonly referred to as pestalotiopsis-like fungi, exhibit a broad distribution and are frequently found as endophytes, saprobes and pathogens across various plant...
, commonly referred to as pestalotiopsis-like fungi, exhibit a broad distribution and are frequently found as endophytes, saprobes and pathogens across various plant hosts. The taxa within pestalotiopsis-like fungi are classified into three genera viz. , and , based on the conidial colour of their median cells and multi-locus molecular phylogenies. In the course of a biodiversity investigation focusing on pestalotiopsis-like fungi, a total of 12 fungal strains were identified. These strains were found to be associated with stromata of , and in various regions of Taiwan from 2018 to 2021. These strains were evaluated morphologically and multi-locus phylogenetic analyses of the ITS (internal transcribed spacer), (translation elongation factor 1-α) and (beta-tubulin) gene regions were conducted for genotyping. The results revealed seven well-classified taxa and one tentative clade in and . One novel species, and four new records, , , and , were reported for the first time in Taiwan. In addition, and an unclassified strain of were identified, based on similarities of phylogeny and morphology. However, the data obtained in the present study suggest that the currently recommended loci for species delimitation of pestalotiopsis-like fungi do not deliver reliable or adequate resolution of tree topologies. The mycelial growth rates of selected strains from these taxa had an optimum temperature of 25 °C, but growth ceased at 5 °C and 35 °C, while all the strains grew faster under alkaline than acidic or neutral pH conditions. This study provides the first assessment of pestalotiopsis-like fungi, associated with entomopathogenic taxa.
PubMed: 38333551
DOI: 10.3897/mycokeys.101.113090 -
Journal of Fungi (Basel, Switzerland) Dec 2023In Colombia, plantings with the oil palm hybrid between × , known as O × G hybrid, have increased due to its tolerance to bud rot. Despite this, different degrees of...
In Colombia, plantings with the oil palm hybrid between × , known as O × G hybrid, have increased due to its tolerance to bud rot. Despite this, different degrees of foliar necrosis, chlorosis, and leaf blight have been reported in some cultivars; therefore, this work aimed to diagnose this problem. We visited plantation plots with palms exhibiting the mentioned symptoms and collected 21 samples of affected tissues in different disease states. The affected tissues were examined and seeded in a culture medium. Pathogenicity tests were performed and the isolates were characterized by culture and morphological and molecular features. , , , and 25 -like fungi were isolated from the foliar lesions. In the pathogenicity tests, the symptoms observed in the field were reproduced with MFTU01-1, MFTU12, and MFTU21 isolates, which were identified at the species level through a sequence analysis of three genes (, , and ) as with an identical level of 99% based on the results of BLAST and phylogenetic tree analyses. The remaining 22 -like non-pathogenic isolates were identified as species of and . The direct association of with the disease was confirmed via molecular detection in affected tissues in 15 of 21 samples collected for this evaluation. This is the first report of as the causal agent of foliar lesions in O × G hybrid oil palm in Colombia.
PubMed: 38248934
DOI: 10.3390/jof10010024 -
Current Medical Mycology Sep 2023Onychomycosis caused by dematiaceous fungi is rarely reported and the identification is also quite tricky due to poor sporulation. Recent emergence of dematiaceous fungi...
BACKGROUND AND PURPOSE
Onychomycosis caused by dematiaceous fungi is rarely reported and the identification is also quite tricky due to poor sporulation. Recent emergence of dematiaceous fungi as a major cause of onychomycosis is a matter of concern in the field of mycology. Therefore, this study aimed to understand the dematiaceous fungi as a possible cause of onychomycosis, especially among agricultural workers. In addition, the evaluation of the antifungal susceptibility patterns led to the idea of an accurate drug that will help to treat and prevent antifungal resistance.
MATERIALS AND METHODS
The standard procedure was followed for direct microscopic examination and fungi isolation. Furthermore, antifungal susceptibility testing was conducted in accordance with the Clinical and Laboratory Standards Institute M-38-A2 protocol.
RESULTS
Both potassium hydroxide and fungal positivity were found in 275 out of 356 suspected cases, 52%, 4.3%, 28.7%, and 14.9% of which were non-dermatophytic molds (NDMs), yeast, dermatophytes, and sterile hyphae, respectively. Among NDMs (52%, n=143), 45.5% (n=65) were hyaline hyphomycetes and 54.5% (n=78) were dematiaceous hyphomycetes. Among dematiaceous fungi, spp. and spp. were the commonly isolated ones. Additionally, azoles, amphotericin-B, and anidulafungin showed excellent antifungal activity against tested isolates.
CONCLUSION
Dematiaceous fungi are now becoming a potential cause of onychomycosis. A more detailed study is needed on the identification of these emerging isolates and the mode of action of antifungal drugs for a better treatment strategy.
PubMed: 38361959
DOI: 10.22034/cmm.2023.345077.1428 -
International Journal of Molecular... Jul 2023sp. is an important class of plant pathogenic fungi that can infect a variety of crops. We have proved the pathogenicity of on bayberry leaves and caused bayberry...
sp. is an important class of plant pathogenic fungi that can infect a variety of crops. We have proved the pathogenicity of on bayberry leaves and caused bayberry blight. Phenazine-1-carboxylic acid (PCA) has the characteristics of high efficiency, low toxicity, and environmental friendliness, which can prevent fungal diseases on a variety of crops. In this study, the effect of PCA on the morphological, physiological, and molecular characteristics of has been investigated, and the potential antifungal mechanism of PCA against was also explored. We applied PCA on in vitro and in vivo to determine its inhibitory effect on PCA. It was found that PCA was highly efficient against with EC around 2.32 μg/mL, and the in vivo effect was 57% at 14 μg/mL. The mechanism of PCA was preliminarily explored by transcriptomics technology. The results showed that after the treatment of PCA, 3613 differential genes were found, focusing on redox processes and various metabolic pathways. In addition, it can also cause mycelial development malformation, damage cell membranes, reduce mitochondrial membrane potential, and increase ROS levels. This result expanded the potential agricultural application of PCA and revealed the possible mechanism against .
Topics: Antifungal Agents; Pestalotiopsis; Fungi
PubMed: 37511033
DOI: 10.3390/ijms241411274 -
Plant Disease Jul 2023Photinia bodinieri Lévl. is an evergreen broadleaf species widely cultivated in subtropical China as an ornamental value (Zhang et al. 2018). In July 2021, leaf spot...
Photinia bodinieri Lévl. is an evergreen broadleaf species widely cultivated in subtropical China as an ornamental value (Zhang et al. 2018). In July 2021, leaf spot symptoms were observed on the campus of Jiangxi Agricultural University (28°45'56″N, 115°50'21″E), Jiangxi province, China. The spots were circular to irregular, gray in the center, and dark brown on the lesion margin. The disease incidence was estimated 15%. Leaf pieces (5 × 5 mm) from the lesion borders were surface-sterilized in 70% ethanol for 30 s, followed by 2% NaOCl for 1 min, and then rinsed three times with sterile water. Tissues were placed on potato dextrose agar (PDA) and incubated at 25°C in the dark. Pure cultures were obtained by monosporic isolation, and the representative isolates, SN-3, SN-7, and SN-11 were used for morphological studies and phylogenetic analyses. The colonies of three isolates grown on PDA were white, cottony, and exhibited flocculent, contained undulate edges with dense aerial mycelium on the surface. Conidia were 5-celled, clavate to fusiform, smooth, 18.2-24.3 × 5.5-8.4 μm (n = 100). The 3 median cells were dark brown to olivaceous, central cell was darker than other 2 cells, and the basal and apical cells were hyaline. Conidia developed filiform appendages; one basal appendage (3.3-8.2 μm long; n = 100), and 2-3 apical appendages (16-29 μm long; n = 100). Morphological features were similar to Neopestalotiopsis sp. (Maharachchikumbura et al. 2014). Portions of internal transcribed spacer (ITS) regions, β-tubulin 2 (TUB2) and translation elongation factor 1-alpha (TEF1-α) genes were amplified from genomic DNA for the three isolates using primers ITS1/ITS4, T1/Bt-2b, EF1-728F/EF-2 (Maharachchikumbura et al. 2014), respectively. All sequences were deposited into GenBank (ITS, OQ572345 - OQ572347; TUB2, OQ597847 - OQ597849; TEF1-α, OQ597844 - OQ597846). A maximum likelihood and Bayesian posterior probability analyses using IQtree v. 1.6.8 and Mr. Bayes v. 3.2.6 with the concatenated sequences placed SN-3, SN-7, and SN-11 in the clade of N. clavispora. Based on the multi-locus phylogeny and morphology, three isolates were identified as N. clavispora. Pathogenicity of the three isolates was verified on nine disease-free 7-year-old Photinia bodinieri plants, which were grown in the field. Two healthy leaves per plant were wounded with two pricks using a sterile needle (Φ=0.5 mm) and inoculated with 20 μL conidial suspension per leaf (106 conidia/mL). Another nine control plants were inoculated with sterile water. 36 leaves were used for the pathogenicity test of three isolates. All leaves were covered with plastic bags to maintain a humid environment for 2 days. The inoculated leaves showed similar symptoms to those observed in the field, whereas control leaves were asymptomatic after 10 days. The fungi were consistently reisolated only from the inoculated and symptomatic leaves, fulfilling Koch's postulates. N. clavispora can cause leaf diseases in a variety of hosts, including Kadsura coccinea (Xie et al. 2018), Photinia serratifolia (Yang et al. 2018), Camellia chrysantha (Zhao et al. 2020). Photinia spp. is an excellent landscape gardening plant, threatened with grey blight (Pestalotiopsis microspore) (Ye et al. 2022), anthracnose (Colletotrichum sp.) (Guan et al. 2013). However, this is the first report of N. clavispora infecting Photinia bodinieri in China. This work provided crucial information for epidemiologic studies and appropriate control strategies for this newly emerging disease.
PubMed: 37467128
DOI: 10.1094/PDIS-06-23-1108-PDN