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Journal of Fungi (Basel, Switzerland) May 2024is a traditional Chinese medicinal plant with a medicinal history of more than 1700 years. Ring leaf blight (RLB) disease, caused by pestalotioid species, is an...
is a traditional Chinese medicinal plant with a medicinal history of more than 1700 years. Ring leaf blight (RLB) disease, caused by pestalotioid species, is an important disease of , seriously affecting the yield and quality of its fruits. The causal agent of RLB disease has not been systematically identified or characterized yet. In this study, thirty-six pestalotioid strains were isolated from the leaves and stems of that was collected from six cities of Hainan province, China. Based on the multi-locus phylogeny (, and ) and morphological characteristic analyses, seventeen species belonging to three genera (, and ) were identified, and six new species (, , , , and ) were described. Pathogenicity tests revealed that strains of species caused more severe ring leaf blight on than strains of and under wounded inoculation conditions.
PubMed: 38921358
DOI: 10.3390/jof10060371 -
Plant Disease Jun 2024Psidium guajava L. is widely cultivated in southern China. In May 2021, guava scab on cv. Zhenzhu was observed in Zhanjiang (21.18° N, 110.21° E), Guangdong province,...
Psidium guajava L. is widely cultivated in southern China. In May 2021, guava scab on cv. Zhenzhu was observed in Zhanjiang (21.18° N, 110.21° E), Guangdong province, China. Guava scab was corky with ovoid or round lesions on the surfaces of green fruits. Gradually the lesions sunk. Disease incidence was estimated as 85% in 500 investigated plants in about 50 ha. Twenty diseased fruits were collected from twenty trees in the field. From each fruit the margin of the diseased tissues was cut into 2 mm × 2 mm pieces; surface disinfected with 75% ethanol and 2% sodium hypochlorite for 30 and 60 s, successively; and rinsed thrice with sterile water. The tissues were plated onto potato dextrose agar (PDA) medium and incubated at 28 ℃. Thirty-four isolates were obtained. Single-spore isolation method (Liu et al. 2021) was used to recover pure cultures of three isolates (PGNC-1, PGNC-2, and PGNC-3) . The colonies were initially white with cottony aerial mycelium at 7 days on PDA. Then, these colonies form black acervular conidiomata at 10 days. Conidia were clavate to fusiform, four-septate, straight or slightly curved, and measured 15.8 to 21.2 µm × 4.5 to 6.5 µm (n = 40). The three median cells were versicolored, whereas the basal and apical cells were hyaline. Conidia had a single basal appendage (4.5 to 5.5 µm long; n = 40) and three apical appendages (19.2 to 24.5 µm long; n = 40). The morphological characteristics of the isolates were consistent with the description of Neopestalotiopsis clavispora (Maharachchikumbura et al. 2012). Molecular identification was performed using PCR method with MightyAmp DNA Polymerase (Takara-Bio, Dalian, China) (Lu et al. 2012). Sequences were generated from the isolates using primers for the rDNA ITS (ITS1/ITS4), TEF1-α (EF1-728F/EF1-986R), and β-tubulin (T1/βt2b) loci (Maharachchikumbura et al. 2012). The sequences of the isolates were submitted to GenBank (ITS, OQ996557 to OQ996559; TEF, OR101037 to OR101039; β-tubulin, OR100971 to OR100973). The sequences of the isolates were 100% identical to the type strain MFLUCC12-0281 (accession nos. JX398979, JX399014, and JX399045) through BLAST analysis. The isolates clustered with N. clavispora (MFLUCC12-0280 and MFLUCC12-0281). N. clavispora and Pestalotiopsis clavispora are synonyms. The pathogenicity was tested in vivo. Plants (cv. Zhenzhu) were grown ( 3 years old) in a quarantine orchard at 25 ℃ to 32 ℃ with 60 to 80% relative humidity in May 2022. Disease-free green fruits were inoculated. Sterile cotton balls were immersed in the spore suspension (1 × 105 per mL) and sterile distilled water (control) for about 15 s before they were fixed on the wounded fruits with transparent tape. Five fruits on one plant per isolate were inoculated. Five fruits on one plant severed as control. The test was performed thrice. Disease symptoms were found on the inoculated fruits after 20 days, whereas the controls remained healthy. The pathogen was re-isolated from infected fruits and was phenotypically identical to the original isolates thus fulfilling Koch's postulates. Neopestalotiopsis or Pestalotiopsis spp. were reported to be the causal agents of guava scab in Colombia and in Hawaii (Keith et al. 2006; Solarte et al. 2018). N. clavispora has been reported to cause disease in a broad range of hosts (Ge et al. 2009; Chen et al. 2018), but not in guava. This is the first report of N. clavispora causing guava scab in China. There would be no harvest if this disease is left unmanaged.
PubMed: 38885025
DOI: 10.1094/PDIS-11-23-2357-PDN -
Natural Product Research Jun 2024Two new alkenyl phenol derivatives, namely pestalol F () and pestalol G (), along with two known compounds, pestalachloride A () and pestalotiopsin J (), were isolated...
Two new alkenyl phenol derivatives, namely pestalol F () and pestalol G (), along with two known compounds, pestalachloride A () and pestalotiopsin J (), were isolated from the culture of the fungus JSQ 12. The structures of these compounds were primarily elucidated by MS, NMR and specific rotation data analysises. These secondary metabolites of were reported for the first time. Compound displayed interesting cytotoxic activity against MCF-7 cell line with the IC value of 29.16 μM, whereas compound exhibited moderate activity towards A549 cell line with the IC value of 35.71 μM. The positive control 5-FU showed cytotoxic effects on MCF-7 and A549 cell lines with the respective IC values of 26.70 and 26.07 μM. Compounds and displayed mild antibacterial activities against with MIC values of 128 and 64 μg/mL (MIC of positive control, penicillin, was 0.016 μg/mL), respectively.
PubMed: 38867712
DOI: 10.1080/14786419.2024.2367012 -
Fitoterapia Jul 2024Biotransformation of ursane-type triterpenoid ilexgenin A by endophytic fungi Lasiodiplodia sp. MQD-4 and Pestalotiopsis sp. ZZ-1, isolated from Ilex pubescences and...
Biotransformation of ursane-type triterpenoid ilexgenin A by endophytic fungi Lasiodiplodia sp. MQD-4 and Pestalotiopsis sp. ZZ-1, isolated from Ilex pubescences and Callicarpa kwangtungensis respectively, was investigated for the first time. Six previously undescribed metabolites (1-6) with 23-norursane triterpenoids skeleton were isolated and their structures were unambiguously established by the analysis of spectroscopic data and single-crystal X-ray crystallographic experiments. Decarboxylation, oxidation, and hydroxylation reactions were observed on the triterpenoid skeleton. Especially, the decarboxylation of C-23 provided definite evidence to understand the biogenetic process of 23-norursane triterpenoids. Moreover, the qualitative analysis of the extract of I. pubescences showed metabolites 1, 3, 4, and 6 could be detected in the originated plant, indicating biotransformation by endophytic fungi is a practical strategy for the isolation of novel natural products. Finally, all isolates were evaluated for the protective activities against HO-induced HUVECs dysfunction in vitro. Compound 5 could improve the viability of endothelial cells and decrease the level of intracellular ROS.
Topics: Triterpenes; Biotransformation; Endophytes; Molecular Structure; Humans; Human Umbilical Vein Endothelial Cells; Ilex; Ascomycota; China
PubMed: 38838828
DOI: 10.1016/j.fitote.2024.106053 -
Science Progress 2024Camptothecin (CPT) is an important alkaloid used for anticancer treatment. It is mainly produced by two endangered and overharvested and plants. Endophytic fungi are...
Camptothecin (CPT) is an important alkaloid used for anticancer treatment. It is mainly produced by two endangered and overharvested and plants. Endophytic fungi are promising alternative sources for CPT production. In the present study, fungi residing within explants of were isolated and their CPT-producing capability of their endophytes was verified via thin-layer chromatography, high-performance liquid chromatography, liquid chromatography/high resolution mass spectrometry, and nuclear magnetic resonance analyses and compared with standards. In addition, MTT and sulforhodamine B assays were selected to test the anticancer effect. The endophytic fungi collection of 62 isolates were assigned to 11 genera, with four common genera (, , , and ) and seven less common genera (, , , , , and ). Moreover, the anticancer activity of extracts was assessed against human lung carcinoma (A549). Among eight potential extracts, only sp. I3R2 was found to be a source of CPT, while the remaining seven extracts have not been discovered potential secondary compounds. Thus, other prominent endophytic fungi might be potential candidates of phytochemicals with anticancer properties.
Topics: Humans; Camptothecin; Endophytes; Fungi; Antineoplastic Agents; A549 Cells; Cell Line, Tumor
PubMed: 38807531
DOI: 10.1177/00368504241253675 -
Plant Disease May 2024In October 2023, a Connecticut grower contacted The Connecticut Agricultural Experiment Station about a field of strawberry plants ( × ) (cv. Ruby June) showing...
In October 2023, a Connecticut grower contacted The Connecticut Agricultural Experiment Station about a field of strawberry plants ( × ) (cv. Ruby June) showing symptoms of severe leaf spotting and visual wilting. Upon visiting the field, leaves had lesions with a diffuse black halo and a light brown center and wilting symptoms, which appeared driven by petiole lesions and presented as dark brown stripes with a reddish-purple halo. Symptoms were observed on 80 to 90% of plants within the block, nearly all of which (>90%) presented with both leaf spots and severe wilting. Diseased tissue was collected from 20 leaves and 25 petioles, sterilized in 0.6% NaOCL, and plated on potato dextrose agar. After hyphal tipping a morphologically identical fungus was isolated from 70% of leaves and 88% of petioles, which formed a dense white mycelial mat with moderate aerial mycelium and conidiomata that exuded dark brown conidial masses. The underside of the mycelial mat was yellowish. Conidia were fusoid, ellipsoid, straight to slightly curved, 4-septate with a single basal appendage and 2-5 apical, matching the description of species within the genus (Maharachchikumbura et al. 2014). The average conidia (n=74) length, not including appendages, was 29.9 ± 2.1 µm and the average width, at the widest point, was 7.5 ± 0.7 µm. Aerial hyphae were collected from two isolates, CT58-1 and CT62-2, and DNA was extracted for further molecular characterization. PCR was performed with primers targeting actin (), β-tubulin (), and ITS prior to amplicon sequencing (Carbone and Kohn 1999; Hassan et al. 2018). Sequences were queried against the NCBI whole genome shotgun database, and aligned sequences from 13 species (including , , and ) were collected for each locus. Sequences were aligned, trimmed, and concatenated using Mega11, and IQ-TREE was employed for model selection (Nguyen et al. 2015; Tamura et al. 2021). A maximum-likelihood tree placed the isolates in a high-confidence cluster with , confirming this placement of these isolates within the genus (CT58-1 Accession #: PP715979-89; PP707735). To confirm pathogenicity, CT58-1 was grown on autoclaved strawberry leaves to induce sporulation, and a suspension of 10 spores/ml was made. Five milliliters of this spore suspension was sprayed on six 6-week-old strawberries (cv. Jewel), and water was sprayed on the same number of control plants. Plants were at 100% humidity for two days and then kept in the greenhouse for 3 weeks to observe symptoms. Inoculated plants presented with identical leaf spot and petiole lesions to field samples and no visual symptoms were observed on control plants. New isolations were made from infected petioles, which produced morphologically identical spores to those described above, and ITS/ loci sequencing yielded sequences identical to those of CT58-1. Spore production and plant inoculations were repeated with this new isolate, and identical symptoms were observed. This is the first report of infecting strawberries in New England and given the high disease incidence in the initial infected field and relative lack of disease in a neighboring field, it is likely that this pathogen was introduced on bare root plants. As the plants were sourced from a nursery in Ontario, Canada, it is likely that the pathogen is capable of overwintering in the Northeastern United States.
PubMed: 38803068
DOI: 10.1094/PDIS-04-24-0893-PDN -
Fitoterapia Jul 2024Five undescribed γ-butyrolactones harzianolides BF (1-5), one precursor harzianolide G (6) along with two known analogues, were isolated and identified from the EtOAc...
Five undescribed γ-butyrolactones harzianolides BF (1-5), one precursor harzianolide G (6) along with two known analogues, were isolated and identified from the EtOAc extract of the liquid fermentation of Trichoderma harzianum ZN-4, which was obtained from the sediment of Zhoushan coastal area. Notably, compound 1 featured an unusual carbon skeleton with methylene-bridged furan rings system. Their structures were determined by detailed interpretation of NMR and mass spectroscopic data, and the absolute configurations were unambiguously established based on ECD quantum chemical calculations. In bioassay, 1 and 7 showed inhibitory activity against Pestalotiopsis theae, with MIC values of 25 and 50 μg/mL, respectively.
Topics: Molecular Structure; 4-Butyrolactone; Hypocreales; Pestalotiopsis; China; Microbial Sensitivity Tests; Animals
PubMed: 38801896
DOI: 10.1016/j.fitote.2024.106039 -
Food Chemistry Aug 2024Wuyi Rock Tea (WRT) has different characteristics of "rock flavor" due to different production areas. In this study, we investigated the flavor characteristics and key...
Wuyi Rock Tea (WRT) has different characteristics of "rock flavor" due to different production areas. In this study, we investigated the flavor characteristics and key components of "rock flavor" and the influence of microorganisms on the substances by combining metabolomics and microbiomics with the Rougui WRTs from the Zhengyan, Banyan, and Waishan production areas. The results showed that Rougui has a strong floral and fruity aroma, which is mainly brought by hotrienol, and the sweet, smooth, and fresh taste is composed of epicatechin gallate, epigallocatechin, epigallocatechin gallate, caffeine, theanine, soluble sugar, and sweet and bitter amino acids. Bacteria Chryseobacterium, Pedobacter, Bosea, Agrobacterium, Stenotrophomonas, and Actinoplanes mainly influence the production of hotrienol, epicatechin gallate, and theanine. Fungi Pestalotiopsis, Fusarium, Elsinoe, Teichospora and Tetracladium mainly influence the production of non-volatile compounds. This study provides a reference for the biological formation mechanism of the characteristic aroma of WRT's "rock falvor".
Topics: Metabolomics; Bacteria; Flavoring Agents; Tea; Taste; Camellia sinensis; Fungi; Odorants; Humans
PubMed: 38648695
DOI: 10.1016/j.foodchem.2024.139376 -
Plants (Basel, Switzerland) Mar 2024Fungal attacks have become a major obstacle in tea plantations. is one of the most devastating fungal pathogens in tea plantations that can severely affect tea yield...
Fungal attacks have become a major obstacle in tea plantations. is one of the most devastating fungal pathogens in tea plantations that can severely affect tea yield and quality. However, the molecular mechanism of resistance genes involved in anthracnose is still largely unknown in tea plants. Here, we found that the laccase gene was involved in the response to fungal infection based on a transcriptome analysis. The full-length CDS of was cloned, and its protein sequence had the closest relationship with the AtLAC15 protein compared to other AtLACs. Tissue-specific expression analysis showed that had higher expression levels in mature leaves and stems than in the other tissues. Subcellular localization showed that the CsLAC37 protein was predominantly localized in the cell membrane. The expression levels of were upregulated at different time points under cold, salt, SA, and ABA treatments. qRT-PCR confirmed that responded to both -like species and infections. Functional validation showed that the hydrogen peroxide (HO) content increased significantly, and POD activity decreased in leaves after antisense oligonucleotide (AsODN) treatment compared to the controls. The results demonstrated that may play an important role in resistance to anthracnose, and the findings provide a theoretical foundation for molecular breeding of tea varieties with resistance to fungal diseases.
PubMed: 38592904
DOI: 10.3390/plants13060884 -
International Journal of Molecular... Mar 2024Tea grey blight disease is one of the most destructive diseases that infects tea and is caused by the pathogen (Sawada) Steyaert. L-theanine is a unique non-protein...
Tea grey blight disease is one of the most destructive diseases that infects tea and is caused by the pathogen (Sawada) Steyaert. L-theanine is a unique non-protein amino acid of the tea plant. Different concentrations of L-theanine exhibit significant inhibitory effects on the growth and sporulation ability of the pathogen causing tea grey blight disease. To understand the effect mechanism of L-theanine on , transcriptome profiling was performed on the pathogenic mycelium treated with three different concentrations of L-theanine: no L-theanine treatment (TH0), 20 mg/mL theanine treatment (TH2), and 40 mg/mL theanine treatment (TH4). The colony growths were significantly lower in the treatment with L-theanine than those without L-theanine. The strain cultured with a high concentration of L-theanine produced no spores or only a few spores. In total, 2344, 3263, and 1158 differentially expressed genes (DEGs) were detected by RNA-sequencing in the three comparisons, Th2 vs. Th0, Th4 vs. Th0, and Th4 vs. Th2, respectively. All DEGs were categorized into 24 distinct clusters. According to GO analysis, low concentrations of L-theanine primarily affected molecular functions, while high concentrations of L-theanine predominantly affected biological processes including external encapsulating structure organization, cell wall organization or biogenesis, and cellular amino acid metabolic process. Based on KEGG, the DEGs of Th2 vs. Th0 were primarily involved in pentose and glucuronate interconversions, histidine metabolism, and tryptophan metabolism. The DEGs of Th4 vs. Th0 were mainly involved in starch and sucrose metabolism, amino sugar, and nucleotide sugar metabolism. This study indicated that L-theanine has a significant impact on the growth and sporulation of the pathogen of tea grey blight disease and mainly affects amino acid metabolism, carbohydrate metabolism, and cellular structure-related biosynthesis processes of pathogenic fungi. This work provides insights into the direct control effect of L-theanine on pathogenic growth and also reveals the molecular mechanisms of inhibition of L-theanine to .
Topics: Transcriptome; Glutamates; Camellia sinensis; Plant Leaves; Tea; Ascomycota
PubMed: 38542498
DOI: 10.3390/ijms25063493