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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 -
Indian Journal of Microbiology Sep 2023Members of the plant mycobiota are all associated to varying degrees with the development of plant diseases. Although many reports on the plant mycobiota are well...
Members of the plant mycobiota are all associated to varying degrees with the development of plant diseases. Although many reports on the plant mycobiota are well documented, the relationships between mycobiota of and plant diseases are poorly understood. Mutual interactions and extent of the roles of microbial communities associated with and the source of pathogens are still unclear, and more research is needed on the health benefits of this ecologically important population. Using high-throughput sequencing, we analyzed the mycobiota composition and ecological guilds of the rhizosphere, root, and phyllosphere of healthy and diseased . from the Tianfu Industrial Park in Panzhou city, Guizhou province. Analysis of community composition showed that the relative abundance of pathogens of leaf spot, including , and in the phyllosphere of diseased plant (LD), were 1.15%, 0.15% and 0.06%, and the relative abundance of and were 0.96% and 0.58% in healthy plant (LH). The alpha diversity indices indicated that fungal diversity was higher in healthy plants compared to diseased plants in each compartment. The alpha diversity index of fungi in the phyllosphere (LH) of healthy . , including Shannon, Chao-1, and Faith-pd indices, was 1.02, 81.50 and 10.42 higher than that of the diseased (LD), respectively. The fungi in the rhizosphere of healthy was 1.03, 59.00 and 5.56 higher than the diseased, respectively. The Shannon index of fungi in the root of healthy was 0.29 higher than that of diseased. Principal Coordinate analysis and ANOSIM results showed that there were significant differences in mycobiota composition between healthy and diseased phyllospheres ( < 0.05), as well as rhizosphere fungal community, while there was no significant difference between healthy and diseased roots ( > 0.05). Linear discriminant analysis effect size revealed that, at different taxonomic levels, there were significantly different taxa between the healthy and diseased plants in each compartment. The ecological guilds differed between healthy and diseased plants according to the FUNGuild analysis. For example, of healthy compared to diseased plants, the percentages of "lichenized-undefined saprotroph" were increased by 2.34%, 0.44%, and 1.54% in the phyllosphere, root, and rhizosphere, respectively. In addition, the plant pathogens existed in each compartment of . , but the percentages of "plant pathogen" were increased by 1.16% in the phyllosphere of diseased compared to healthy plants. Together, the ecological guild and co-occurrence network indicated that the potential pathogens of leaf spot were mainly found in the phyllosphere. This study explained one of pathogen origin of leaf spots of by the microbial community ecology, which will provide the new insights for identification of plant pathogens.
PubMed: 37781006
DOI: 10.1007/s12088-023-01093-6 -
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 -
Plant Physiology and Biochemistry : PPB Sep 2023Dendrobium catenatum, which belongs to the Orchidaceae family, has been used as a traditional medicine and healthy food in China for over 2000 years, and is of enormous...
Interactions between endophytic fungus Pestalotiopsis sp. DO14 and Dendrobium catenatum: Deciphering plant polysaccharide and flavonoid accumulation and underlying mechanisms by comparative transcriptome and metabolome analyses.
Dendrobium catenatum, which belongs to the Orchidaceae family, has been used as a traditional medicine and healthy food in China for over 2000 years, and is of enormous economic value. Polysaccharides and flavonoids are two major functional ingredients in D. catenatum stems that contribute to its health benefits. D. catenatum lives in close association with endophytic fungi, but the literature regarding the further relations between them, especially the fungal-induced accumulation of metabolites in the host plant, is sparse. Our previous study showed that Pestalotiopsis sp. DO14 isolated from D. catenatum improved the host plant growth and metabolite accumulation. This study was performed to investigate dynamic variations of the growth traits, key metabolites (polysaccharides and flavonoids), and expression of key genes of D. catenatum under conditions of the DO14 colonization. Colonization with DO14 promoted D. catenatum growth as indicated by increased leaf area, mid-stem thickness, and plant height. The content of polysaccharides, mannose, and sucrose increased even without DO14 entering the host cells or forming a mature symbiotic relationship concurrent with improved photosynthesis rate. Furthermore, DO14 induced upregulation of genes involved in sugar and flavonoid metabolism, especially phosphoenolpyruvate carboxykinase (PCKA), chalcone synthase (CHS) and UDP-glycose flavonoid glycosyltransferase (UFGT). These observations suggested that endophytic fungi induce the accumulation of polysaccharides and flavonoids by plants, increasing the efficiency of carbon assimilation and carbon turnover. The findings of this study provide insight into the mechanisms underlying Orchidaceae-endophyte interactions, and suggest potential novel applications of endophytic fungi in D. catenatum breeding to improved plant quality.
Topics: Flavonoids; Dendrobium; Transcriptome; Pestalotiopsis; Plant Breeding; Polysaccharides; Metabolome
PubMed: 37562204
DOI: 10.1016/j.plaphy.2023.107942 -
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