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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 -
Marine Drugs Dec 2023Chemical epigenetic cultivation of the sponge-derived fungus sp. SWMU-WZ04-1 contributed to the identification of twelve polyketide derivatives, including six new...
Chemical epigenetic cultivation of the sponge-derived fungus sp. SWMU-WZ04-1 contributed to the identification of twelve polyketide derivatives, including six new pestalotiopols E-J (-) and six known analogues (-). Their gross structures were deduced from 1D/2D NMR and HRESIMS spectroscopic data, and their absolute configurations were further established by circular dichroism (CD) Cotton effects and the modified Mosher's method. In the bioassay, the cytotoxic and antibacterial activities of all compounds were evaluated. Chlorinated benzophenone derivatives and exhibited inhibitory effects on and , with MIC values varying from 3.0 to 50 μg/mL. In addition, these two compounds were cytotoxic to four types of human cancer cells, with IC values of 16.2~83.6 μM. The result showed that compound had the probability of being developed into a lead drug with antibacterial ability.
Topics: Humans; Pestalotiopsis; Anti-Bacterial Agents; Bacillus subtilis; Fungi; Polyketides
PubMed: 38248640
DOI: 10.3390/md22010015 -
PLoS Biology Jan 2024Chitin deacetylases (CDAs) emerge as a valuable tool to produce chitosans with a nonrandom distribution of N-acetylglucosamine (GlcNAc) and glucosamine (GlcN) units. We...
Chitin deacetylases (CDAs) emerge as a valuable tool to produce chitosans with a nonrandom distribution of N-acetylglucosamine (GlcNAc) and glucosamine (GlcN) units. We hypothesized before that CDAs tend to bind certain sequences within the substrate matching their subsite preferences for either GlcNAc or GlcN units. Thus, they deacetylate or N-acetylate their substrates at nonrandom positions. To understand the molecular basis of these preferences, we analyzed the binding site of a CDA from Pestalotiopsis sp. (PesCDA) using a detailed activity screening of a site-saturation mutagenesis library. In addition, molecular dynamics simulations were conducted to get an in-depth view of crucial interactions along the binding site. Besides elucidating the function of several amino acids, we were able to show that only 3 residues are responsible for the highly specific binding of PesCDA to oligomeric substrates. The preference to bind a GlcNAc unit at subsite -2 and -1 can mainly be attributed to N75 and H199, respectively. Whereas an exchange of N75 at subsite -2 eliminates enzyme activity, H199 can be substituted with tyrosine to increase the GlcN acceptance at subsite -1. This change in substrate preference not only increases enzyme activity on certain substrates and changes composition of oligomeric products but also significantly changes the pattern of acetylation (PA) when N-acetylating polyglucosamine. Consequently, we could clearly show how subsite preferences influence the PA of chitosans produced with CDAs.
Topics: Chitosan; Chitin; Polymers; Amidohydrolases; Acetylation
PubMed: 38236907
DOI: 10.1371/journal.pbio.3002459 -
Journal of Natural Products Jan 2024One novel rearranged pimarane diterpenoid, pestanoid A (), and two reported molecules, nodulisporenones A () and B (), were discovered from sp. NBUF145 fungus...
One novel rearranged pimarane diterpenoid, pestanoid A (), and two reported molecules, nodulisporenones A () and B (), were discovered from sp. NBUF145 fungus associated with a 62 m deep mesophotic ("twilight") zone Chalinidae sponge. The structures of - were identified by spectrometry, spectroscopy, quantum-chemical calculations, and X-ray crystallography. Compounds and inhibited bone marrow monocyte osteoclastogenesis with the IC values 4.2 ± 0.2 μM and 3.0 ± 0.4 μM, respectively, without observed cytotoxicity. Both and suppressed the receptor activator of NF-kB ligand-induced MAPK and NF-κB signaling by inhibiting the phosphorylation of ERK1/2-JNK1/2-p38 MAPKs and NF-κB nuclear translocation.
Topics: Osteogenesis; Osteoclasts; NF-kappa B; Pestalotiopsis; Macrophages; Abietanes; RANK Ligand
PubMed: 38194474
DOI: 10.1021/acs.jnatprod.3c00892 -
Plant Disease Jan 2024In September 2022, leaf blight symptoms (Fig. 1) were detected on six-year-old kiwi trees (Actinidia chinensis cv. 'Hongyang') in Xuzhou municipality (117.29º E,...
In September 2022, leaf blight symptoms (Fig. 1) were detected on six-year-old kiwi trees (Actinidia chinensis cv. 'Hongyang') in Xuzhou municipality (117.29º E, 34.23º N), Jiangsu Province. Early-stage disease symptoms included light brown necrotic lesions of irregular shape ranging in length from 0.2 to 2.4 cm, which turned into leaf blight after approximately 2 weeks. Those symptoms were similar to those previously reported during a Pestalotiopsis sp. infection on kiwi trees in Turkey (Karakaya 2001). Approximately 20% of the leaves from 300 trees examined in one kiwi orchard, 3000 m2 in size, showed the disease symptoms. Ten leading edges of symptomatic leaves were sterilized with 2% sodium hypochlorite for 1 min, rinsed twice with sterile ddH2O and cultured at 26ºC for 3 days on PDA medium containing 50 µg/ml chloramphenicol. The fungal colonies were collected, and the single spore isolation method was used to obtain four isolates. The obtained isolates showed white aerial mycelia that turned greyish after 2 days of cultivation on PDA medium at 26ºC. ITS (OR054113, OR054153-OR054155), TUB2 (OR060951-OR060953, OR249978), and CMD (OR255947-OR255950) genes were amplified using the ITS1/ITS4, BT2a/BT2b and CMD5/CMD6 primers, respectively (Visagie et al. 2014a). The obtained ITS, TUB2, and CMD sequences shared 99.81%-100%, 96.72%-96.96%, and 90.17%-92.58% homology compared to the ex-type strain P. oxalicum CBS 219.30 (MH855125, KF296462, and KF296367), while the obtained ITS and TUB2 sequences showed 99.62%-99.81%, and 96.46%-96.72% identity compared to the representative strain P. oxalicum DTO 179B9 (KJ775647 and KJ775140) (Visagie et al. 2014b). The sequences obtained also showed high homology compared to P. oxalicum HP7-1 (ITS: 99.81%-100% homology; TUB2: 98.98%-99.38% homology; CMD: 94.71%-95.10% homology) (Li et al. 2022). A molecular phylogenetic tree was constructed using MEGA X with representative Penicillium strains retrieved from GenBank (Fig. 2). Microscope observations revealed the presence of curved septate hyphae. Conidia were colorless, unicellular, and ellipsoidal (5-8 μm in length; > 2000 observations), whereas conidiophores were mainly monoverticillate (approximately 20% of the conidiophores were biverticillate) (50-70 μm in length; 43 observations) and contained cylindrical phialides (13-15 μm in length). These findings are consistent with P. oxalicum morphology (Wu et al. 2022; Zheng et al. 2023). The pathogenicity of the four isolates was screened using healthy non-detached 'Hongyang' kiwi leaves. Fifteen leaves from five different two-month-old trees were used for each isolate, with three repetitions. For inoculation, a 10 mL solution containing 1 × 106 spores/mL was sprayed on the leaves. Sterilized water was used in the control experiment, which was carried out using fifteen leaves from five different two-month-old trees, with three repetitions. Inoculated trees were stored at 26ºC and 60% relative humidity for 2 days. All the infected leaves had necrotic lesions and leaf blight symptoms comparable to those found in the field, but the control leaves had no lesions. The pathogen was recovered, and its identity was confirmed by ITS sequencing and morphology analysis, fulfilling Koch's postulates. P. oxalicum is a common cause of blue mould in postharvest fruits (Tang et al. 2020). P. oxalicum has been recently reported as the causal agent of leaf spot in pineapple (Wu et al. 2022; Zheng et al. 2023), and leaf blight on maize (Han et al. 2023). Although Alternaria sp., Glomerella cingulate, Pestalotiopsis sp., Phomopsis sp., and Phoma sp. were previously isolated from kiwi leaves with blight symptoms (Kim et al. 2017), this is the first report of P. oxalicum causing leaf blight on kiwi trees worldwide. P. oxalicum is a well-known source of mycotoxins, such as secalonic acid (Otero et al. 2020), indicating that its presence in kiwifruit orchards may pose a significant risk to human health. The discovery of this hazardous pathogen in kiwi trees must drive the development of management strategies. Kiwifruit is an important dietary source of vitamins, fiber, folate, and potassium, and China is the major producer of kiwifruit, with more than 1.2 million metric tons harvested in 2021. This report will help to generate a better understanding of the pathogens affecting kiwifruit orchards in China.
PubMed: 38170442
DOI: 10.1094/PDIS-07-23-1341-PDN -
Journal of Fungi (Basel, Switzerland) Dec 2023Leaf spot is a common disease of (), which can seriously harm the plant's ability to grow, flower, and fruit. Therefore, it is important to identify the mechanism of...
Leaf spot is a common disease of (), which can seriously harm the plant's ability to grow, flower, and fruit. Therefore, it is important to identify the mechanism of leaf spot caused by () for thorough comprehension and disease control. In this study, to verify whether the mycotoxins produced by cause leaf spot disease, the best medium for , namely PDB, was used. The mycotoxins were determined by ammonium sulfate precipitation as non-protein substances. The crude mycotoxin of was prepared, and the optimal eluent was eluted with petroleum either/ethyle acetate (3:1, /) and purified by silica gel column chromatography and preparative high-performance liquid chromatography to obtain the pure mycotoxins PK-1, PK-2, and PK-3. The PK-3 had the highest toxicity to , which may be the primary mycotoxin, according to the biological activity test using the spray method. The physiological and biochemical indexes of plants treated with PK-3 mycotoxin were determined. Within 35 days after mycotoxin treatment, the results showed that the protein content and malondialdehyde content of leaves increased over time. The soluble sugar and chlorophyll content decreased over time. The superoxide dismutase activity and catalase activity of the leaves increased first and then decreased, and the above changes were the same as those of inoculated with the spore suspension of the pathogen. Therefore, it is believed that the mycotoxin pestalopyrone could be a virulence factor that helps induce the infection of . In this study, the pathogenic mechanism of leaf spot was discussed, offering a theoretical foundation for improved disease prevention and control.
PubMed: 38132794
DOI: 10.3390/jof9121194 -
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 -
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 -
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