Dissecting infectious bronchitis virus-induced host shutoff at the translation level.

Viruses have evolved a range of strategies to utilize or manipulate the host's cellular translational machinery for efficient infection, although the mechanisms by which infectious bronchitis virus (IBV) manipulates the host translation machinery remain unclear. In this study, we firstly demonstrate that IBV infection causes host shutoff, although viral protein synthesis is not affected. We then screened 23 viral proteins, and identified that more than one viral protein is responsible for IBV-induced host shutoff, the inhibitory effects of proteins Nsp15 were particularly pronounced. Ribosome profiling was used to draw the landscape of viral mRNA and cellular genes expression model, and the results showed that IBV mRNAs gradually dominated the cellular mRNA pool, the translation efficiency of the viral mRNAs was lower than the median efficiency (about 1) of cellular mRNAs. In the analysis of viral transcription and translation, higher densities of RNA sequencing (RNA-seq) and ribosome profiling (Ribo-seq) reads were observed for structural proteins and 5' untranslated regions, which conformed to the typical transcriptional characteristics of nested viruses. Translational halt events and the number of host genes increased significantly after viral infection. The translationally paused genes were enriched in translation, unfolded-protein-related response, and activation of immune response pathways. Immune- and inflammation-related mRNAs were inefficiently translated in infected cells, and IBV infection delayed the production of IFN-ß and IFN-λ. Our results describe the translational landscape of IBV-infected cells and demonstrate new strategies by which IBV induces host gene shutoff to promote its replication. IMPORTANCE: Infectious bronchitis virus (IBV) is a γ-coronavirus that causes huge economic losses to the poultry industry. Understanding how the virus manipulates cellular biological processes to facilitate its replication is critical for controlling viral infections. Here, we used Ribo-seq to determine how IBV infection remodels the host's biological processes and identified multiple viral proteins involved in host gene shutoff. Immune- and inflammation-related mRNAs were inefficiently translated, the translation halt of unfolded proteins and immune activation-related genes increased significantly, benefitting IBV replication. These data provide new insights into how IBV modulates its host's antiviral responses.

Identification and Comparison of the Sialic Acid-Binding Domain Characteristics of Avian Coronavirus Infectious Bronchitis Virus Spike Protein.

Infectious bronchitis virus (IBV) infections are initiated by the transmembrane spike (S) glycoprotein, which binds to host factors and fuses the viral and cell membranes. The N-terminal domain of the S1 subunit of IBV S protein binds to sialic acids, but the precise location of the sialic acid binding domain (SABD) and the role of the SABD in IBV-infected chickens remain unclear. Here, we identify the S1 N-terminal amino acid (aa) residues 19 to 227 (209 aa total) of IBV strains SD (GI-19) and GD (GI-7), and the corresponding region of M41 (GI-1), as the minimal SABD using truncated protein histochemistry and neuraminidase assays. Both α-2,3- and α-2,6-linked sialic acids on the surfaces of CEK cells can be used as attachment receptors by IBV, leading to increased infection efficiency. However, 9-O acetylation of the sialic acid glycerol side chain inhibits IBV S1 and SABD protein binding. We further constructed recombinant strains in which the S1 gene or the SABD in the GD and SD genomes were replaced with the corresponding region from M41 by reverse genetics. Infecting chickens with these viruses revealed that the virulence and nephrotropism of rSDM41-S1, rSDM41-206, rGDM41-S1, and rGDM41-206 strains were decreased to various degrees compared to their parental strains. A positive sera cross-neutralization test showed that the serotypes were changed for the recombinant viruses. Our results provide insight into IBV infection of host cells that may aid vaccine design. IMPORTANCE To date, only α-2,3-linked sialic acid has been identified as a potential host binding receptor for IBV. Here, we show the minimum region constituting the sialic acid binding domain (SABD) and the binding characteristics of the S1 subunit of spike (S) protein of IBV strains SD (GI-19), GD (GI-7), and M41 (GI-1) to various sialic acids. The 9-O acetylation modification partially inhibits IBV from binding to sialic acid, while the virus can also bind to sialic acid molecules linked to host cells through an α-2,6 linkage, serving as another receptor determinant. Substitution of the putative SABD from strain M41 into strains SD and GD resulted in reduced virulence, nephrotropism, and a serotype switch. These findings suggest that sialic acid binding has diversified during the evolution of γ-coronaviruses, impacting the biological properties of IBV strains. Our results offer insight into the mechanisms by which IBV invades host cells.

Identification of transcriptionally-active human papillomavirus integrants through nanopore sequencing reveals viable targets for gene therapy against cervical cancer.

Integration of the human papillomavirus (HPV) genome into the cellular genome is a key event that leads to constitutive expression of viral oncoprotein E6/E7 and drives the progression of cervical cancer. However, HPV integration patterns differ on a case-by-case basis among related malignancies. Next-generation sequencing technologies still face challenges for interrogating HPV integration sites. In this study, utilizing Nanopore long-read sequencing, we identified 452 and 108 potential integration sites from the cervical cancer cell lines (CaSki and HeLa) and five tissue samples, respectively. Based on long Nanopore chimeric reads, we were able to analyze the methylation status of the HPV long control region (LCR), which controls oncogene E6/E7 expression, and to identify transcriptionally-active integrants among the numerous integrants. As a proof of concept, we identified an active HPV integrant in between RUNX2 and CLIC5 on chromosome 6 in the CaSki cell line, which was supported by ATAC-seq, H3K27Ac ChIP-seq, and RNA-seq analysis. Knockout of the active HPV integrant, by the CRISPR/Cas9 system, dramatically crippled cell proliferation and induced cell senescence. In conclusion, identifying transcriptionally-active HPV integrants with Nanopore sequencing can provide viable targets for gene therapy against HPV-associated cancers.

Effect of mPEG-PLGA on Drug Crystallinity and Release of Long-Acting Injection Microspheres: In Vitro and In Vivo Perspectives.

PURPOSE: Traditional progesterone (PRG) injections require long-term administration, leading to poor patient compliance. The emergence of long-acting injectable microspheres extends the release period to several days or even months. However, these microspheres often face challenges such as burst release and incomplete drug release. This study aims to regulate drug release by altering the crystallinity of the drug during the release process from the microspheres. METHODS: This research incorporates methoxy poly(ethylene glycol)-b-poly(lactide-co-glycolide) (mPEG-PLGA) into poly(lactide-co-glycolide) (PLGA) microspheres to enhance their hydrophilicity, thus regulating the release rate and drug morphology during release. This modification aims to address the issues of burst and incomplete release in traditional PLGA microspheres. PRG was used as the model drug. PRG/mPEG-PLGA/PLGA microspheres (PmPPMs) were prepared via an emulsification-solvent evaporation method. Scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC) were employed to investigate the presence of PRG in PmPPMs and its physical state changes during release. RESULTS: The addition of mPEG-PLGA altered the crystallinity of the drug within the microspheres at different release stages. The crystallinity correlated positively with the amount of mPEG-PLGA incorporated; the greater the amount, the faster the drug release from the formulation. The bioavailability and muscular irritation of the long-acting injectable were assessed through pharmacokinetic and muscle irritation studies in Sprague-Dawley (SD) rats. The results indicated that PmPPMs containing mPEG-PLGA achieved low burst release and sustained release over 7 days, with minimal irritation and self-healing within this period. PmPPMs with 5% mPEG-PLGA showed a relative bioavailability (Frel) of 146.88%. IN CONCLUSION: In summary, adding an appropriate amount of mPEG to PLGA microspheres can alter the drug release process and enhance bioavailability.

Synchronous Computed Tomography-Guided Percutaneous Transthoracic Needle Biopsy and Microwave Ablation for Highly Suspicious Malignant Pulmonary Ground-Glass Nodules.

INTRODUCTION: There is no consensus regarding the most appropriate management of suspected malignant pulmonary ground-glass nodules (GGNs). OBJECTIVE: We aimed to explore the feasibility and safety of synchronous computed tomography-guided percutaneous transthoracic needle biopsy (PTNB) and microwave ablation (MWA) for patients highly suspicious of having malignant GGNs. METHODS: We retrospectively reviewed medical records between July 2020 and April 2023 from our medical center. Eligible patients synchronously underwent PTNB and MWA (either MWA immediately after PTNB [PTNB-first group] or PTNB immediately after MWA [MWA-first group]) at the the physician's discretion. We analyzed the rate of definitive diagnosis and technical success, the length of hospital stay, the postoperative efficacy, and periprocedural complications. RESULTS: Of 65 patients who were enrolled, the rate of definitive diagnosis was 86.2%, which did not differ when stratified by the tumor size, the consolidation-to-tumor ratio, or the sequence of the two procedures (all p > 0.05). The diagnostic rate of malignancy was 83.1%. After the median follow-up duration of 18.5 months, the local control rate was 98.2% and the rate of completed ablation was 48.2%. The rate of perioperative minor and major complications was 44.6% and 6.2%, respectively. The most common adverse events included pain, cough, and mild hemorrhage. Mild hemorrhage took place significantly less frequently in the MWA-first group than in the PTNB-first group (16.7% vs. 45.5%, p < 0.05). CONCLUSION: Synchronous PTNB and MWA are feasible and well tolerated for patients highly suspicious of having malignant GGNs, providing an alternative option for patients who are ineligible for surgical resection.

Fruit Anthracnose on Cavendish bananas Caused by Colletotrichum fructicola in Guangxi, China.

Cavendish banana (Musa spp. AAA group) is one of the main fruit crops worldwide. It is widely planted in Guangdong, Hainan, Guangxi, Fujian and Yunnan provinces in southern China. In November 2020, banana fruits with anthracnose symptoms were collected from Dayu Town (N 23.17°, E 109.80°), Guigang City, and Chengjun Town (N 22.60°, E 110.00°), Yulin City, Guangxi Province, China, where the disease was found on about 70% of the banana plants, and on individual fruit, up to 10% of the surface was covered with symptoms. The symptoms initially began with rust-colored spots on the surface of the immature fruit, which gradually became sunken and cracked as the disease progressed. Small tissues (5×5 mm) from the pericarp at the junction of disease and health were surface-disinfected in 75% ethanol for 10 s, 2% sodium hypochlorite (NaClO) for 1 min, and washed three times in sterile water. Tissue pieces were placed on potato dextrose ager (PDA) and incubated at 25°C. Fifty-nine morphologically similar colonies were obtained after 5 days of incubation, with 100% isolation frequency. Of 59 isolates, GG1-3 isolated from Guigang City and YL4-2 isolated from Yulin City were selected as representative strains for intensive study. Mycelia were off-white for both isolates and conidia obtained from PDA were cylindrical, unicellular, hyaline and obtuse ends, with sizes of 11.5 ± 1.8×3.9 ± 0.8 µm (n=60) and 11.5 ± 1.6×4.1 ± 0.6 µm (n=60) for GG1-3 and YL4-2, respectively (Prihastuti et al. 2009). Genomic DNA was extracted from 7-day-old aerial mycelia using a DNAsecure Plant Kit (Tiangen Biotech, China). The internal transcribed spacer (ITS), the intergenic region of apn2 and MAT1-2-1 (ApMAT) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were amplified and sequenced (White et al. 1990; Silva et al.2012; Templeton et al. 1992). Sequences were deposited in GenBank (ITS, OR596961 to OR596962; GAPDH, OR661771 to OR661772; APMAT, OR661773 to OR661774) and showed 100% identities with the corresponding type strains sequences of C. fructicola. Phylogenetic tree was constructed with software raxmlGUI v.2.0.0 based on sequences of multiple loci (ITS, GAPDH and ApMAT) and Maximum Likelihood method. Phylogenetic analysis revealed that the two isolates and C. fructicola were clustered in the same clade, with 94% bootstrap support. According to morphology and phylogenetic analysis, the two isolates GG1-3 and YL4-2 were identified as C. fructicola. For pathogenicity tests, healthy fruits were surface sterilized with 75% ethanol followed by a wash with sterilized water. Five adjacent needle punctures in a 5-mm-diameter circle were made with a sterilized needle on healthy fruits, followed by inoculation with 20 µL of conidial suspension (106 spores/ml), and sterilized water was used as controls. All banana fruit were incubated in a humid chamber at 28°C. After 4 days, all inoculated fruits showed visible symptoms and had rust-colored spots on the margins, while control banana fruits remained symptomless. The fungus was isolated from the inoculated fruit and the isolates were found to match the morphological and molecular characteristics of the original isolates, confirming Koch's hypothesis. To our knowledge, this is the first report of fruit anthracnose on Cavendish bananas caused by C. fructicola in China. This study will provide valuable information for prevention and management of anthracnose on banana fruit.

Identification and Characterization of Colletotrichum Species Associated with Anthracnose Disease of Plum.

Plum (Prunus salicina Lindl.) is commercially cultivated worldwide for the high levels of nutrients in the fruit. In recent years, anthracnose has been severe in some plum planting areas in China, resulting in a large number of necrotic leaves, blight and pre-mature leaf fall. In this study, anthracnose samples of plum leaves were collected from Hezhou, Guilin and Lipu, Guangxi Province, and Meishan city, Abe Tibetan and Qiang autonomous prefecture of Sichuan Province. Characteristics of mycelia on PDA, morphology of appressoria and conidia, and analysis of sequences of several marker regions (internal transcribed spacer [ITS] region, glyceraldehyde-3-phosphate dehydrogenase [GAPDH], chitin synthase [CHS-1], histone H3 [HIS3], actin [ACT], ß-tubulin [TUB2], and the intergenic region between apn2 and MAT1-2-1 [ApMat]). The resulting 101 Colletotrichum isolates obtained were identified as eight species: C. fructicola (50.5%), C. siamense (24.8%), C. karsti (8.9%), C. plurivorum (7.9%), C. aeschynomenes (3.9%), C. gloeosporioides (2%), C. celtidis (1%) and C. phyllanthi (1%). Representatives of all eight Colletotrichum species were found to cause disease on wounded leaves of plum seedlings in pathogenicity assays. As far as we are aware, this is the first report of anthracnose of plum caused by C. celtidis and C. phyllanthi in China.

First Report of Anthracnose Caused by Colletotrichum plurivorum on Passion fruit in Guangxi, China.

Passion fruit (Passiflora edulis Sims.) is popular for its rich taste and nutritional value. The planting area of passion fruit in Guangxi has reached 24,300 ha, with an annual output of 380,000 t (Qian 2023). In March 2023, leave spots on more than half of the plants (cv. Qinmi "NO.9"). Moreover, the incidence of disease on the leaves was approximately 20% in Shabu Town, Qinnan District, Qinzhou City, Guangxi, China (N20˚54'-22˚41', E107˚27'-109˚56'). Leaf diseases were orbicular or irregular in shape, white, whitish-grey, yellowish, or gray in color. When leaves were severely affected, larger blotches were formed with yellow halos. For pathogen isolation, three diseased leaf samples were collected from three gardens, respectively, and 5×5 mm tissues were cut from infected margins, surface-disinfected in 75% ethanol for 15 s, followed by 2% sodium hypochlorite for 1 min, rinsed three times with sterile water, and incubated on PDA at 25°C under 12/12 h light/darkness. After 5 days, ninety cultures were isolated, sixty isolates with similar morphology were retained, and three representative isolates BY-1, BY-2, and BY-4 were randomly selected for further study. On PDA, colonies of the three isolates displayed white or grayish-white. Conidia were single-celled, hyaline, and cylindrical, measuring 17.3±1.5 × 6.3±0.7 µm, 17.8±1.7 × 6.0±0.6 µm, and 16.3±1.4 × 6.4±0.6 µm (n=90) for BY-1, BY-2, and BY-4, respectively. Appressoria were single, brown or black, and irregular in shape, measuring 10.2±1.1×6.5±0.5 µm, 10.5±1.3×7.3±0.6, and 10.9±0.8×7.0±0.8 (n=90) for BY-1, BY-2, and BY-4, respectively. These morphological characteristics were similar to Colletotrichum spp. as previously described (Damm et al. 2019). The isolates were further identified by sequencing the internal transcribed spacer (ITS-ITS1/ITS4), glyceraldehyde-3-phosphate dehydrogenase (GAPDH-GDF/GDR), actin (ACT-512F/783R), partial sequences of the chitin synthase 1 (CHS-1-79F/354R), and beta-tubulin 2 (TUB2-T1/Bt2b) (Zhang et al. 2023). All sequences were deposited in GenBank (ITS: OR741759 to OR741761, GAPDH: OR767654 to OR767656, ACT: OR767657 to OR767659, CHS-1: OR767660 to OR767662, TUB2: OR767651 to OR767653). A phylogenetic tree was built with RAxML version 8.2.10 based on concatenated sequences of ITS-GAPDH-ACT-CHS-1-TUB2. The results revealed that the three isolates clustered with C. plurivorum. To confirm the pathogenicity of the three isolates, attached leaves of healthy 5-month-old passion fruit plants were injured in the middle region with sterile toothpicks and inoculated with 20 µL of spore suspension (106 conidia/mL), and the noninoculated control received 0.05% Tween-20 (6 leaves/plant, 3 plants/treatment). The inoculated plants were kept in a greenhouse at 25°C and covered with plastic bags to maintain high humidity. After 9 days, all inoculated leaves were symptomatic, whereas no symptoms were observed in the control. C. plurivorum was reisolated from infected leaves, confirming Koch's postulates. C. plurivorum has been reported to infect Abelmoschus esculentus (Batista et al. 2020) and Carya illinoinensis in China (Zhang et al. 2023). However, this is the first report of anthracnose caused by C. plurivorum on passion fruit in China. The results can provide a robust basis for scientific prevention and control of anthracnose.

Assessment Methods and Intervention Strategies for Cleft-Related Lateral Misarticulation in Chinese-Speaking Children.

The aim of this study was to analyze the characteristics and error speech features of cleft-related lateral misarticulation and provide a basis for clinical evaluation and rational intervention. Participants who were diagnosed with lateral misarticulation after cleft palate repairment were 126 children aged 4, 6 to 16, and 11, and they had complete palatopharyngeal closure, no abnormalities in their speech organs and occlusion, and no hearing or intellectual impairments. The Chinese standard pronunciation clarity word list, the American KAY CSL4500, the Beijing Yangchen YF-16 computer speech analysis workstation, soundproof rooms, Wechsler scales of intelligence-fourth edition, and audiometers were used to evaluate the cleft-related lateral misarticulation. Statistical analysis was performed on the age, gender, error rate, corner of the mouth deviation direction, comorbidity, duration of intervention, period of treatment, and therapeutic effect of concentrated or normal intervention group in different patients. Our results showed that 2 to 3 straight stripes were visible at the onset of consonants /ti:/ /t'i:/, and 3 clear straight lines were visible in /tʂ/, indicating that the lateralized sound had 2 or 3 bursts and lasted for 1 to 2 ms. The onset age of lateralized sound was mostly below 12 years old. Chinese lateralized sound mainly occurred in vowel /i:/, and the occurrence rate of consonants with tongue surface /tɕ]/ /tɕ'/ /ɕ/ was the highest. In addition, the corner of the mouth deviation was also an indicator of lateralization sound, and other types of speech disorders mostly accompanied it. There was a significant difference in the improvement of speech clarity between the concentrated intervention group and the normal group before and after treatment. The 2 groups' average duration and course of treatment were not significantly different. Still, the period of concentrated intervention was shortened considerably, and the speech clarity of both groups of children after treatment exceeded 96%, reaching a normal level.

Synergistic interaction of Cu(II) with caffeic acid and chlorogenic acid in α-glucosidase inhibition.

BACKGROUND: Phenolic acids are widespread in foods and are beneficial to human health. However, the role of metal ions in influencing the binding of proteins with phenolic acids that contain the same parent nucleus structure remains unclear. This study investigated the inhibitory effect of caffeic acid (CA) and chlorogenic acid (CHA) on α-glucosidase and the biological effect of copper on this process. RESULTS: It was found that the esterification of CA with quinic acid could increase the fluorescence quenching, conformational change, and inhibitory effect of CHA on α-glucosidase. Copper ions reduced their fluorescence quenching and conformation-changing ability by binding to the neighboring phenolic hydroxyl group but also increased their ability to alter secondary structure and to inhibit α-glucosidase and in vitro anti-glycation. CONCLUSION: Overall, this study shows that the binding of copper ions to the phenolic hydroxyl group adjacent to CA and CHA synergistically inhibited α-glucosidase. The findings will offer a theoretical basis for investigating the properties of metal ions and phenolic acid in food chemistry and their potential applications in the prevention and treatment of diabetes mellitus. © 2023 Society of Chemical Industry.

GBCdb: RNA expression landscapes and ncRNA-mRNA interactions in gallbladder carcinoma.

Gallbladder carcinoma (GBC), an aggressive malignant tumor of the biliary system, is characterized by high cellular heterogeneity and poor prognosis. Fewer data have been reported in GBC than other common cancer types. Multi-omics data will contribute to the understanding of the molecular mechanisms of cancer, cancer diagnosis and prognosis. Herein, to provide better understanding of the molecular events in GBC pathogenesis, we developed GBCdb ( http://tmliang.cn/gbc/ ), a user-friendly interface for the query and browsing of GBC-associated genes and RNA interaction networks using published multi-omics data, which also included experimentally supported data from different molecular levels. GBCdb will help to elucidate the potential biological roles of different RNAs and allow for the exploration of RNA interactions in GBC. These resources will provide an opportunity for unraveling the potential molecular features of Gallbladder carcinoma.

Mutagenesis of the di-leucine motif in the cytoplasmic tail of newcastle disease virus fusion protein modulates the viral fusion ability and pathogenesis.

BACKGROUND: Newcastle disease virus (NDV) is a highly infectious viral disease, which can affect chickens and many other kinds of birds. The main virulence factor of NDV, the fusion (F) protein, is located on the viral envelope and plays a major role in the virus' ability to penetrate cells and cause host cell fusion during infection. Multiple highly conserved tyrosine and di-leucine (LL) motifs in the cytoplasmic tail (CT) of the virus may contribute to F protein functionality in the viral life cycle. METHODS: To examine the contribution of the LL motif in the biosynthesis, transport, and function of the F protein, we constructed and rescued a NDV mutant strain, rSG10*-F/L537A, with an L537A mutation using a reverse genetic system. Subsequently, we compared the differences in the syncytium formation ability, pathogenicity, and replication levels of wild-type rSG10* and the mutated strain. RESULTS: Compared with rSG10*, rSG10*-F/L537A had attenuated syncytial formation and pathogenicity, caused by a viral budding defect. Further studies showed that the LL-motif mutation did not affect the replication, transcription, or translation of the virus genome but affected the expression of the F protein at the cell surface. CONCLUSIONS: We concluded that the LL motif in the NDV F CT affected the regulation of F protein expression at the cell surface, thus modulating the viral fusion ability and pathogenic phenotype.

Characterization of a novel hypovirus isolated from the phytopathogenic fungus Colletotrichum camelliae.

Some members of genus Colletotrichum are important plant pathogens. Here, we report a novel positive single-stranded RNA virus, Colletotrichum camelliae hypovirus 1 (CcHV1), from strain GXNN11-2 of Colletotrichum camelliae. The complete genome of CcHV1 is 9907 nucleotides (nt) in length and contains a single large open reading frame (ORF) from nt 352 to 9006. This ORF encodes a polyprotein with four conserved domains, namely UDP-glycosyltransferase, RNA-dependent RNA polymerase (RdRp), peptidase, and DEAD-like helicase. The CcHV1 polyprotein shares the highest similarity with Fusarium concentricum hypovirus 1. Phylogenetic analysis indicated that CcHV1 clustered with members of the genus Betahypovirus within the family Hypoviridae. This is the first report of a hypovirus in a member of the genus Colletotrichum.

Passive directivity detection of acoustic sources based on acoustic Luneburg lens.

This article reports an acoustic Luneburg lens (ALL) design with graded refractive index for passive directivity detection of acoustic sources. The refractive index profile of the lens is realized based on square pillars with graded variation of their dimensions. Numerical and experimental studies are conducted to investigate the performance of directivity detection. The results demonstrate that the lens designed and developed in this study is capable of precisely detecting the directivity of one acoustic source. Furthermore, the directivities of two acoustic sources can also be detected with a resolution of 15°. In addition, different methods are investigated, including introducing phase difference by tuning input signals or moving ALL, and increasing the aperture size of ALL, to improve the resolution of dual sources directivity detection.

Identification and Observation of Infection Processes of Colletotrichum Species Associated with Persimmon Anthracnose in Guangxi, China.

Persimmon originated from China where it has a long cultivation history. Anthracnose fruit rot and leaf blight caused by Colletotrichum species are major diseases of persimmon in China and cause severe economic losses. To determine the species causing anthracnose of persimmon in Guilin, Guangxi Province, diseased samples were collected from the four local counties: Gongcheng, Yangshuo, Pingle, and Lipu. Seventy-five isolates were obtained from persimmon samples with anthracnose symptoms and had similar morphological characteristics. Isolates were identified using a BLAST search and phylogenetic analysis of the internal transcribed spacer region, glyceraldehyde-3-phosphate dehydrogenase, partial actin, ß-tubulin, chitin synthase genomic regions, Apn2-Mat1-2 intergenic spacer, and the partial mating type gene and calmodulin genes. Five species (C. fructicola, C. horii, C. karstii, C. cliviicola, and C. siamense) accounted for 54.7, 25.3, 12.0, 5.3, and 2.7%, respectively, of the total isolates. All five Colletotrichum species were pathogenic on attached leaves and detached fruits of persimmon (cultivar Gongcheng Yueshi) in pathogenicity assays. The infection processes of the five Colletotrichum species were observed on persimmon leaves using light microscopy. Conidia of C. fructicola germinated at 12 h post inoculation (hpi) and quickly formed acervuli at 6 days post inoculation (dpi) and were the most aggressive. By contrast, conidia of C. cliviicola germinated at 3 hpi but produced the acervuli at 8 dpi and were the least aggressive. This is the first description of C. fructicola, C. cliviicola, and C. siamense as causal agents of persimmon anthracnose in Guangxi Province, China.

Leaf Spot of Sanhua Plum caused by Botryosphaeria wangensis in China.

Sanhua plum (Prunus salicina L.) is planted widely in Babu district of Hezhou, Guangxi with a planting history of more than 70 years (Zhou et al., 2021). In August 2021, leaf spot disease was observed with approximately 50% incidence on Sanhua plum leaves in Babu district in Hezhou, Guangxi (N23°49'-24°48', E111°12'-112°03'). The symptoms initially appeared as small, round, and chlorotic spots. As the disease progressed, the lesions enlarged and margins became dark brown. To isolate the pathogen, small pieces (5 × 5 mm) of the infected tissue margins were sterilized by exposure to 75% ethanol for 10 sec, 2% sodium hypochlorite for 1 min and rinsed three times in sterile water. Pieces were incubated on potato dextrose agar (PDA) at 28℃. In total, 75 isolates were obtained from leaves which were collected from three trees. Fifty of them were morphologically identical with a 67% average isolation frequency. Three representative isolates (HZ13-1, HZ26-3 and HZ47-1) were selected for further study. The cultures on PDA were initially white, fluffy with uneven margins and turned smoky gray to olivaceous at the surface. The reverse sides were olivaceous gray to iron gray after seven days. The growth rate of mycelium was 2.5 cm/day. Conidia were produced after two weeks by exposure to near-fluorescent light for 10 hours per day. Conidia were fusiform, hyaline, thin-walled, smooth with granular contents unicellular, and 19.7 ± 0.13 × 5.8 ± 0.06 µm (n=90), 19.8 ± 0.09 × 6.5 ± 0.23 µm (n=90), and 20.6 ± 0.20 × 6.7 ± 0.12 µm (n=90) for HZ13-1, HZ26-3 and HZ47-1, respectively. These characteristics were consistent with the descriptions of the Botryosphaeria wangensis (Hattori et al. 2021). The DNA was extracted from mycelia, and the internal transcribed spacer (ITS), elongation factor 1-alpha gene (EF1-α) and ß-tubulin (TUB2) were amplified using the primer pairs ITS1/ITS4, EF1-728F/EF1-986R and T1/BT2b (White et al. 1990, Carbone et al. 1999, Yu et al. 2021), respectively. The sequences were compared with GenBank and they all showed over 99% identity to the type strain of B. wangensis CERC 2298 (Li et al. 2020). Sequences of the three isolates were deposited in GenBank (Accession Nos.: ITS, OP804110-OP804112; EF1-α, OP821748-OP821750; TUB2, OP821745-OP821747). The three isolates were identified as B. wangensis based on the maximum likelihood phylogenetic tree of concatenated sequences of ITS, EF1-α, and TUB2 with RAxML version 2.0. Pathogenicity tests were performed on healthy leaves of 2-year-old Sanhua plum, which were wounded by a sterilized needle in a greenhouse. A 5-mm-diam hyphal plug was placed on the wound. Each isolate was used to inoculate three plants, with 20 leaves per plant. Control plants were inoculated with sterile PDA plugs. All the plants were sprayed with distilled water and covered with plastic bags. After four days of incubation at 28℃ with constant light, lesion began to develop in the inoculated leaves. After ten days, the average diameter of lesions was up to 1.5 cm but controls remained symptom-free. The fungi were reisolated from inoculated symptomatic leaves and were identical to the inoculated isolates, thus completing Koch's postulates. To our knowledge, this is the first report of B. wangensis associated with leaf spot of Sanhua plum in China. The results will contribute to accelerating the development of future epidemiological studies of B. wangensis on Sanhua plum.

Bacterial Leaf Spot of Plum Caused by Sphingomonas spermidinifaciens in Guangxi, China.

Plum (Prunus salicina L.) is a traditional fruit in Southern China and is ubiquitous throughout the world. In August 2021, leaves of plum trees showed water-soaking spots and light yellow-green halos with incidence exceeding 50% in Babu district in Hezhou, Guangxi (N23°49'-24°48', E111°12'-112°03'). To isolate the causal agent, three diseased leaves collected from three different trees growing in different orchards were cut into 5 mm × 5 mm pieces, disinfected with 75% ethanol for 10 sec, 2% sodium hypochlorite for 1 min and rinsed three times in sterile water. The diseased pieces were ground in sterile water and then kept static for about 10 min. Ten-fold serial dilutions in water were prepared and 100 µL of each dilution from 10-1 to 10-6 were plated on Luria-Bertani (LB) Agar. After incubation at 28℃ for 48 h, the proportion of isolates with similar morphology was 73%. Three representative isolates (GY11-1, GY12-1 and GY15-1) were selected for further study. The colonies were non-spore-forming, yellow, round, opaque, rod shaped, convex with smooth and bright neat edges. Biochemical test results showed that the colonies were strictly aerobic and gram-negative. The isolates were able to grow on LB agar containing 0-2% (w/v) NaCl and could utilize glucose, lactose, galactose, mannose, sucrose, maltose and rhamnose as a carbon source. They displayed a positive reaction for H2S production, oxidase, catalase and gelatin, but negative for starch. Genomic DNA of the three isolates was extracted for amplification of the 16S rDNA with primers 27F and 1492R. The resulting amplicons were sequenced. Additionally, five housekeeping genes atpD, dnaK, gap, recA, and rpoB of the three isolates were amplified using the corresponding primer pairs and sequenced. The sequences were deposited in GenBank (16S rDNA, OP861004-OP861006; atpD, OQ703328-OQ703330; dnaK, OQ703331-OQ703333; gap, OQ703334-OQ703336; recA, OQ703337-OQ703339; and rpoB, OQ703340-OQ703342). The isolates were identified as Sphingomonas spermidinifaciens based on the phylogenetic tree inferred by maximum-likelihood using MegaX 7.0 of the concatenated six sequences (multilocus sequence analysis, MLSA) compared with sequences from different Sphingomonas type strains . Pathogenicity of the isolates was tested on healthy leaves of the two-year-old plum plants in a greenhouse. The leaves were wounded by a sterilized needle and sprayed with bacterial suspensions prepared in PBS (Phosphate buffer saline) at OD600=0.5. PBS buffer solution was used as negative control. Each isolate was used to inoculate on 20 leaves per plum tree. The plants were covered with plastic bags to maintain high humidity. Dark brown-to-black lesions were observed on leaves 3 days post incubation at 28℃ with constant light. The average diameter of lesions was 1 cm after seven days, but the negative controls were symptomless. Bacteria reisolated from the diseased leaves were the same as the ones used for inoculation on the basis of morphological and molecular identification, fulfilling Koch's postulates. Plant disease caused by a Sphingomonas species has been reported on mango, pomeand Spanish melon. However, this is the first report of S. spermidinifaciens causing leaf spot disease of plum in China. This report will help to develop effective disease control strategies in the future.

Fruit Rot Caused by Fusarium sulawesiense on Chilli in Guangxi, China.

Chilli (Capsicum annuum) is considered as one of the most important vegetables and spice crops throughout the world which is widely cultivated in China. In October 2019, fruit rot symptoms were observed on chilli in Guilin, Guangxi, China (N24°18', E109°45'). Irregular dark green spots initially appeared on the middle or bottom of the fruit, then extended to larger grayish brown lesions and started to rot. In the late stage, the whole fruit dried up after water loss. Three disease samples were collected from three towns of different counties in Guilin where the disease incidence of chilli fruits was 15-30%. The margin of diseased fruits was cut into small pieces (3×3 mm), disinfected with 75% ethanol solution for 10 s, 2% NaOCl for 1 min, and rinsed in sterile distilled water three times. Tissue pieces were separately plated on potato dextrose agar (PDA) and incubated at 25°C for seven days. Fifty-four fungal isolates with similar morphology were consistently recovered from diseased tissues of three fruits, with 100% isolation frequency. Three representatives GC1-1, GC2-1 and PLX1-1 were selected for further analysis. The colonies produced abundant whitish to yellowish aerial mycelium on PDA after 7 days incubation at 25°C in the dark. Macroconidia cultured on carnation leaf agar (CLA) for 7 days were long, hyaline, falcate, with dorsal and ventral lines often gradually wider toward apex, curved apical cell and foot-shaped basal cell, mostly 2 to 5 septa, and ranged from 24.16 to 38.88 × 3.36 to 6.55 µm (average 31.39×4.48 µm), from 19.44 to 28.68 × 3.02 to 4.99 µm (average 23.02×3.89 µm), and from 20.96 to 35.05 × 3.30 to 6.06 µm (average 26.24×4.51 µm) for GC1-1, GC2-1, and PLX1-1, respectively. Microconidia were hyaline, fusoid or ovoid, one-septate or nonseptate, and ranged from 4.61 to 10.14 × 2.61 to 4.77 µm (average 8.13×3.58 µm), from 3.55 to 7.85 × 1.95 to 3.04 µm (average 5.79×2.39 µm), and from 6.75 to 18.48 × 3.05 to 9.07 µm (average 14.32×4.31 µm) for GC1-1, GC2-1, and PLX1-1, respectively. Genomic DNA was extracted from 7-day-old aerial mycelia of these isolates. The internal transcribed spacer (ITS), translation elongation factor (TEF1), calmodulin (CAM) and partial RNA polymerase second largest subunit (RPB2) were amplified using primers ITS4/ITS1, EF1/EF2, CL1/CL2A, and 5F2/7cR, respectively (White et al. 1990; O'Donnell et al. 2000, 2010). Sequences were deposited in GenBank (ITS: OQ080044-OQ080046; TEF1: OQ101589-OQ101591; CAM: OQ101586-OQ101588; RPB2: OQ101592-OQ101594). A maximum Likelihood (ML) phylogenetic tree was constructed with RAxML version 8.2.10 based on the concatenated sequences (ITS, CAM, TEF1, RPB2). According to morphology and phylogenetic analysis, the isolates were identified as Fusarium sulawesiense (Maryani et al. 2019). For pathogenicity tests, multiple punctures in a 5-mm-diameter circle were made with a sterilized toothpick on detached young healthy fruits, followed by inoculation with 10 µl of conidial suspension (106 spores/ml in 0.1% sterile Tween 20). Each isolate was inoculated onto eighteen fruits. Controls were inoculated with water containing 0.1% sterile Tween 20 under the same conditions. Symptoms were observed on the inoculated fruits 7 days after incubation at 25°C, whereas non-inoculated controls were asymptomatic. The fungus was re-isolated from inoculated chilli fruits, completing Koch's postulates. To our knowledge, this is the first report of Fusarium sulawesiense causing fruit rot on Chilli in China. These results will provide valuable information for prevention and management of fruit rot on Chilli.

Leaf Spot Caused by Colletotrichum siamense, C. fructicola, and C. aeschynomenes on Ixora chinensis in Guangxi, China.

Ixora chinensis Lam., an important ornamental flower, has become more and more popular in the southwest and southeast regions of China for its bright and abundant flowers (Li et al. 2019). In March 2022, 100% I. chinensis plants showed typical anthracnose symptoms on leaf in Nanning, Guangxi, China (108°22' N, 22°48' E). The central areas of lesions were grayish white with small black particles arranged in a wheel pattern, and the edges of lesions were light red to brown. Three diseased leaf samples were collected from three gardens, respectively. 5×5 mm tissues were cut from infected margins, surface-disinfected in 75% ethanol for 10 s, 2% NaClO for 2 min, rinsed three times in sterilized distilled water, and incubated on PDA at 25°C under 12/12 h light/darkness. Eighty-three morphologically similar colonies were observed on PDA after 5 days, and eight isolates G1-3, G2-1, G3-3, W-1, W-2, LCH2-1, LCH3-3, and LCH4-1 were selected for further study. Genomic DNA of these isolates were extracted from 7-day-old mycelia. Primer pairs ITS1/ITS4, GDF1/GDR1, T1/ßt2b, CHS Ⅰ-79F/CHS Ⅰ-354R, CL1/CL2, ACT-512F/ACT-783R, and MAT1-2-1/apn2 were used to amplify ITS loci and GAPDH, CHS-Ⅰ, CAL, ACT, ApMAT genes, respectively (Yang et al. 2009; Silva et al. 2012; Liu et al. 2015). Sequences have been deposited in GenBank (ITS: OQ771884 to OQ771891, GAPDH: OQ759576 to OQ759583, TUB2: OQ759584 to OQ759591, CHS-1: OQ759568 to OQ759575, CAL: OQ759560 to OQ759567, ACT: OQ759552 to OQ759559, ApMat: OQ759544 to OQ759551). Phylogenetic analysis was performed with raxmlGUI v.2.0.0. based on combined sequences of ITS, GAPDH, TUB2, CHS-1, CAL, ACT, and ApMAT using maximum parsimony analysis. The results revealed that isolates G2-1 and W-2 were clustered with Collectrichum fructicola, G3-3, W-1, G1-3, LCH2-1, and LCH3-3 were clustered with C. siamense, and LCH4-1 was clustered with C. aeschynomenes. Three representative isolates W-2, G3-3, and LCH4-1 were selected for morphology and pathogenicity observation. On PDA, the colonies of three isolates presented white to grey cottony mycelia，from the margin to the center, W-2 was white, grey, and light gray, G3-3 showed light gray, white, and grey, LCH4-1 was white and light gray, respectively. Conidia were all hyaline, one-celled, cylindrical, and straight. The conidial sizes of W-2, G3-3, and LCH4-1 were 11.03 to 17.53 × 4.93 to 8.42 µm (n=100), 10.63 to 19.06 × 3.73 to 6.92 µm (n=100), and 11.61 to 20.39 × 3.65 to 6.67 µm (n=100), respectively. Pathogenicity tests of three isolates were conducted on leaves of 1-year-old I. chinensis plants with and without wounds, three plants for each treatment, and five leaves inoculated for each plant. Conidial suspensions (10 µL, 106 conidia/mL in 0.1% sterile Tween 20) were inoculated on each site. Control group was treated with 0.1% sterile Tween 20. All inoculated sites were covered with wet cotton, and all plants were bagged and placed in the greenhouse to maintain humidity at 25℃. After 10 days, all wounded and inoculated leaves showed leaf spot, whereas unwounded and control leaves remained asymptomatic. Koch's postulates were fulfilled by re-isolating the causal agents from diseased leaves. C. siamense and C. aeschynomenes could cause anthracnose of I. chinensis in China (Liu et al. 2016, Li et al. 2021). However, to our knowledge, this is the first report of C. fructicola infecting I. chinensis in China. This study may provide reference for further epidemiological study and prevention of anthracnose on I. chinensis.

Fruit Rot on Persimmon Caused by Neopestalotiopsis saprophytica and Neopestalotiopsis ellipsospora in Guangxi, China.

Persimmon (Diospyros kaki Thunb.) is widely cultivated in China. On October 15, 2019, about 10% of persimmon fruits showed fruit rot in the orchards of Guilin, Guangxi, China (24°45' N, 110°24' E), which could cause more than 15% of yield losses. The initial symptoms of fruit rot exhibited irregular brown to black spots (range from 2 to 4 cm in diameter), the areas surrounding the blackened spots would be soft and rotten, and three diseased fruit samples were collected from three orchards, respectively. Tissues (5×5 mm) were cut from infected margins, surface-disinfected in 75% ethanol for 10 s, 2% NaClO for 2 min, rinsed three times in sterilized distilled water, and incubated on potato dextrose agar (PDA) at 25°C under 12/12 h light/darkness for a week. Forty-one tissues yielded morphologically similar cultures, and three representative isolates LPG1-1, LPG1-2, and YSG-1 were selected from three samples for further study, respectively. Their colonies showed wavy edges, white surfaces, and dense aerial hyphae on PDA after two weeks. Conidia were fusiform, straight to slightly curved, and 4-septate; basal cells were conical, hyaline, thin, and verruculose with two or three long and hyaline apical appendages and one short apical appendage; three median cells of LPG1-1 with length 14.06 to 17.69 µm (n=100), and LPG1-2 with length 14.03 to 17.61 µm (n=100) were dark brown to olivaceous, while three median cells of YSG-1 with length 12.54 to 15.58 µm (n=100) were dark brown. The conidial sizes of LPG1-1, LPG1-2, and YSG-1 were 17.41 to 27.68 × 4.63 to 8.55 µm (n=100), 18.06 to 27.41 × 4.33 to 8.21 µm (n=100), and 16.58 to 27.73 × 4.99 to 8.39 µm (n=100), respectively. The morphological characteristics were consistent with Neopestalotiopsis spp. (Maharachchikumbura et al. 2012; Maharachchikumbura et al. 2014). Primer pairs ITS4/ITS5, BT2a/BT2b, and EF1-526F/EF-1567R were used to amplify internal transcribed spacer (ITS), beta-tubulin (TUB2), and translation elongation factor 1 alpha (TEF1-α), respectively (Shu et al., 2020). All DNA fragments were sequenced by Sangon Biotech Co., Ltd. (Shanghai, China). Sequences have been deposited in GenBank (ITS: OM349120 to OM349122, TUB2: OM688188 to OM688190, TEF1-α: OM688191 to OM688193). Based on BLASTn analysis of ITS, TUB2, and TEF1-α sequences, the LPG1-1 and LPG1-2 showed over 99% similarity to N. saprophytica, and YSG-1 showed over 99% similarity to N. ellipsospora. Phylogenetic analysis of the three isolates was performed with MEGA10 (version 10.0) based on sequences of ITS, TUB2, and TEF1-α using maximum parsimony analysis. The results revealed that LPG1-1 and LPG1-2 were clustered with N. saprophytica, and YSG-1 was clustered with N. ellipsospora. Pathogenicity tests of three isolates were conducted on 72 healthy persimmon fruits with and without wounds, and 9 fruits are for each treatment. The wound was made by a sterilized needle. Fruits were pre-processed with 75% ethanol for 10 s, 1% NaClO for 2 min and rinsed three times in sterile water. Conidial suspensions (10 µL, 106 conidia/mL in 0.1% sterile Tween 20) were inoculated on each site (4 sites/fruit). Control group was treated with 0.1% sterile Tween 20. All inoculated sites were covered with wet cotton. The inoculated fruits were placed in a plastic box to maintain humidity at 28℃. After 5 days, all wounded fruits showed fruit rot, whereas unwounded and control fruits remained asymptomatic, there were significant differences (P<0.05) in aggressiveness between N. saprophytica (average lesion diameter 13.1 mm) and N. ellipsospora (average lesion diameter 14.9 mm). Koch's postulates were fulfilled by re-isolating the causal agents from inoculated fruits. N. ellipsospora was previously reported as an endophyte in D. montana in southern India (Reddy et al. 2016). N. saprophytica could cause leaf spot of Erythropalum scandens and Magnolia sp., and fruit rot of Litsea rotundifolia in China and leaf spot of Elaeis guineensis in Malaysia (Yang et al. 2021, Ismail et al. 2017). To our knowledge, this is the first report of N. ellipsospora and N. saprophytica causing fruit rot on persimmon in the world. The results will provide a foundation for controlling fruit rot caused by pestalotioid fungi on persimmon.