RBM10 regulates the tumorigenic potential of human cancer cells by modulating PPM1B and YBX1 activities.

RNA binding protein RBM10 participates in various RNA metabolism, and its decreased expression or loss of function by mutation has been identified in many human cancers. However, how its dysregulation contributes to human cancer pathogenesis remains to be determined. Here, we found that RBM10 expression was decreased in breast tumors, and breast cancer patients with low RBM10 expression presented poorer survival rates. RBM10 depletion in breast cancer cells significantly promotes the cellular proliferation and migration. We further demonstrated that RBM10 forms a triple complex with YBX1 and phosphatase 1B (PPM1B), in which PPM1B serves as the phosphatase of YBX1. RBM10 knock-down markedly attenuated association between YBX1 and PPM1B, leading to elevated levels of YBX1 phosphorylation and its nuclear translocation. Furthermore, cancer cells with RBM10 depletion had a significantly accelerated tumor growth in nude mice. Importantly, these enhanced tumorigenic phenotypes can be reversed by overexpression of PPM1B. Our findings provide the mechanistic bases for functional loss of RBM10 in promoting tumorigenicity, and are potentially useful in the development of combined therapeutic strategies for cancer patients with defective RBM10.

Decoupling Carrier-Phonon Scattering Boosts the Thermoelectric Performance of n-Type GeTe-Based Materials.

The coupled relationship between carrier and phonon scattering severely limits the thermoelectric performance of n-type GeTe materials. Here, we provide an efficient strategy to enlarge grains and induce vacancy clusters for decoupling carrier-phonon scattering through the annealing optimization of n-type GeTe-based materials. Specifically, boundary migration is used to enlarge grains by optimizing the annealing time, while vacancy clusters are induced through the aggregation of Ge vacancies during annealing. Such enlarged grains can weaken carrier scattering, while vacancy clusters can strengthen phonon scattering, leading to decoupled carrier-phonon scattering. As a result, a ratio between carrier mobility and lattice thermal conductivity of ∼492.8 cm3 V-1 s-1 W-1 K and a peak ZT of ∼0.4 at 473 K are achieved in Ge0.67Pb0.13Bi0.2Te. This work reveals the critical roles of enlarged grains and induced vacancy clusters in decoupling carrier-phonon scattering and demonstrates the viability of fabricating high-performance n-type GeTe materials via annealing optimization.

Piezocatalysis for Chemical-Mechanical Polishing of SiC: Dual Roles of t-BaTiO3 as a Piezocatalyst and an Abrasive.

Chemical mechanical polishing (CMP) offers a promising pathway to smooth third-generation semiconductors. However, it is still a challenge to reduce the use of additional oxidants or/and energy in current CMP processes. Here, a new and green atomically smoothing method: Piezocatalytic-CMP (Piezo-CMP) is reported. Investigation shows that the Piezo-CMP based on tetragonal BaTiO3 (t-BT) can polish the rough surface of a reaction sintering SiC (RS-SiC) to the ultra-smooth surface with an average surface roughness (Ra) of 0.45 nm and the rough surface of a single-crystal 4H-SiC to the atomic planarization Si and C surfaces with Ra of 0.120 and 0.157 nm, respectively. In these processes, t-BT plays a dual role of piezocatalyst and abrasive. That is, it piezo-catalytically generates in-situ active oxygen species to selectively oxidize protruding sites of SiC surface, yielding soft SiO2, and subsequently, it acts as a usual abrasive to mechanically remove these SiO2. This mechanism is further confirmed by density functional theory (DFT) calculation and molecular simulation. In this process, piezocatalytic oxidation is driven only by the original pressure and friction force of a conventional polishing process, thus, the piezo-CMP process do not require any additional oxidant and energy, being a green and effective polishing method.

A moisture-enabled fully printable power source inspired by electric eels.

Great efforts have been made to build integrated devices to enable future wearable electronics; however, safe, disposable, and cost-effective power sources still remain a challenge. In this paper, an all-solid-state power source was developed by using graphene materials and can be printed directly on an insulating substrate such as paper. The design of the power source was inspired by electric eels to produce programmable voltage and current by converting the chemical potential energy of the ion gradient to electric energy in the presence of moisture. An ultrahigh voltage of 192 V with 175 cells in series printed on a strip of paper was realized under ambient conditions. For the planar cell, the mathematical fractal design concept was adapted as printed patterns, improving the output power density to 2.5 mW cm-3, comparable to that of lithium thin-film batteries. A foldable three-dimensional (3D) cell was also achieved by employing an origami strategy, demonstrating a versatile design to provide green electric energy. Unlike typical batteries, this power source printed on flexible paper substrate does not require liquid electrolytes, hazardous components, or complicated fabrication processes and is highly customizable to meet the demands of wearable electronics and Internet of Things applications.

Predictive model and risk analysis for coronary heart disease in people living with HIV using machine learning.

OBJECTIVE: This study aimed to construct a coronary heart disease (CHD) risk-prediction model in people living with human immunodeficiency virus (PLHIV) with the help of machine learning (ML) per electronic medical records (EMRs). METHODS: Sixty-one medical characteristics (including demography information, laboratory measurements, and complicating disease) readily available from EMRs were retained for clinical analysis. These characteristics further aided the development of prediction models by using seven ML algorithms [light gradient-boosting machine (LightGBM), support vector machine (SVM), eXtreme gradient boosting (XGBoost), adaptive boosting (AdaBoost), decision tree, multilayer perceptron (MLP), and logistic regression]. The performance of this model was assessed using the area under the receiver operating characteristic curve (AUC). Shapley additive explanation (SHAP) was further applied to interpret the findings of the best-performing model. RESULTS: The LightGBM model exhibited the highest AUC (0.849; 95% CI, 0.814-0.883). Additionally, the SHAP plot per the LightGBM depicted that age, heart failure, hypertension, glucose, serum creatinine, indirect bilirubin, serum uric acid, and amylase can help identify PLHIV who were at a high or low risk of developing CHD. CONCLUSION: This study developed a CHD risk prediction model for PLHIV utilizing ML techniques and EMR data. The LightGBM model exhibited improved comprehensive performance and thus had higher reliability in assessing the risk predictors of CHD. Hence, it can potentially facilitate the development of clinical management techniques for PLHIV care in the era of EMRs.

Developing an entrustable professional activity for providing health education and consultation in occupational therapy and examining its validity.

BACKGROUND: Entrustable Professional Activities (EPA)-based assessment is easily and intuitively used in evaluating the learning outcomes of competency-based medical education (CBME). This study aimed to develop an EPA for occupational therapy focused on providing health education and consultation (TP-EPA3) and examine its validity. METHODS: Nineteen occupational therapists who had completed online training on the EQual rubric evaluation participated in this study. An expert committee identified six core EPAs for pediatric occupational therapy. TP-EPA3 was developed following the EPA template and refined through consensus meetings. The EQual rubric, a 14-item, five-point criterion-based anchor system, encompassing discrete units of work (DU), entrustable, essential, and important tasks of the profession (EEIT), and curricular role (CR), was used to evaluate the quality of TP-EPA3. Overall scores below 4.07, or scores for DU, EEIT, and CR domains below 4.17. 4.00, and 4.00, respectively, indicate the need for modifications. RESULTS: The TP-EPA3 demonstrated good validity, surpassing the required cut-off score with an average overall EQual score of 4.21 (SD = 0.41). Specific domain scores for DU, EEIT, and CR were 3.90 (SD = 0.69), 4.46 (SD = 0.44), and 4.42 (SD = 0.45), respectively. Subsequent revisions clarified observation contexts, enhancing specificity and focus. Further validation of the revised TP-EPA3 and a thorough examination of its reliability and validity are needed. CONCLUSION: The successful validation of TP-EPA3 suggests its potential as a valid assessment tool in occupational therapy education, offering a structured approach for developing competency in providing health education and consultation. This process model for EPA development and validation can guide occupational therapists in creating tailored EPAs for diverse specialties and settings.

Arthroscopy-assisted reduction and simultaneous robotic-assisted screw placement in the treatment of fractures of the posterior talar process.

PURPOSE: A fracture of the posterior talar process is easily missed because of its hidden position. Inappropriate treatment is likely to result in complications, such as nonunion of the fracture and traumatic arthritis. This study evaluated the outcomes of arthroscopy-assisted reduction combined with robotic-assisted screw placement in the treatment of fractures of the posterior talar process. METHODS: The clinical data for nine patients who underwent surgical treatment of a fracture of the posterior talar process at our institution between September 2017 and January 2021 were retrospectively reviewed. Arthroscopy-assisted reduction of the fracture was performed, and a cannulated screw was placed using three-dimensional orthopedic robotic-assisted navigation. RESULTS: The patients (seven men, two women) had a mean age of 36.33 ± 9.77 years and were followed up for 21 ± 5.43 months. The operation time was 106.67 ± 24.5 min with blood loss of 47.78 ± 9.05 ml. Primary healing was obtained in all cases, and no patient sustained a nerve or tendon injury, had fracture nonunion, or developed talar osteonecrosis. One patient developed subtalar arthritis, for which subtalar joint fusion was performed; pain was markedly less severe after cleaning. CONCLUSION: Arthroscopy-assisted reduction and robotic-assisted screw placement have the advantages of visualization of fracture reduction, minimal injury, and precise screw placement in the treatment of fractures of the posterior talar process.

Horizontal Transport in Ti3C2Tx MXene for Highly Efficient Osmotic Energy Conversion from Saline-Alkali Environments.

Osmotic energy from the ocean has been thoroughly studied, but that from saline-alkali lakes is constrained by the ion-exchange membranes due to the trade-off between permeability and selectivity, stemming from the unfavorable structure of nanoconfined channels, pH tolerance, and chemical stability of the membranes. Inspired by the rapid water transport in xylem conduit structures, we propose a horizontal transport MXene (H-MXene) with ionic sequential transport nanochannels, designed to endure extreme saline-alkali conditions while enhancing ion selectivity and permeability. The H-MXene demonstrates superior ion conductivity of 20.67 S m-1 in 1 M NaCl solution and a diffusion current density of 308 A m-2 at a 10-fold salinity gradient of NaCl solution, significantly outperforming the conventional vertical transport MXene (V-MXene). Both experimental and simulation studies have confirmed that H-MXene represents a novel approach to circumventing the permeability-selectivity trade-off. Moreover, it exhibits efficient ion transport capabilities, addressing the gap in saline-alkali osmotic power generation.

Comprehensive analysis of differences in N6-methyladenosine RNA methylomes in the rat adenohypophysis after GnRH treatment.

N6-methyladenosine is considered to be the most common and abundant internal chemical modification among the more than 150 identified chemical RNA modifications. It is involved in most biological processes and actively participates in the regulation of animal reproduction. However, the potential function of m6 A in the pituitaries of mammals is not yet clear. It is also unknown whether m6 A is involved in the secretion and regulation of FSH by GnRH, which in turn affects mammalian reproduction. In this study, rats were treated with gonadorelin to simulate physiological GnRH-mediated regulation of FSH synthesis and secretion, and m6 A-seq was used to analyze the differential m6 A modification of the rat pituitary after gonadorelin treatment. A whole-transcriptome map of m6 A in the rat pituitary gland before and after gonadorelin treatment was successfully created. A total of 6413 differential peaks were identified, of which 3764 m6 A peaks were upregulated and 2649 m6 A peaks were downregulated. Among the 709 differentially expressed genes, 250 genes were discovered with differential methylation modifications. Intriguingly, the altered m6 A peaks within mRNAs were enriched in steroid biosynthetic processes and responses to cAMP. The results of the study will lay a foundation for further exploration of the potential role of m6 A modification in the regulation of reproductive hormone secretion and provide a theoretical basis for the application of GnRH analogs in mammalian artificial reproduction.

Predicting estimated glomerular filtration rate after partial and radical nephrectomy based on split renal function measured by radionuclide: a large-scale retrospective study.

PURPOSE: The purpose of this study was to develop predictive models for postoperative estimated glomerular filtration rate (eGFR) based on the split glomerular filtration rate measured by radionuclide (rGFR), as choosing radical nephrectomy (RN) or partial nephrectomy (PN) for complex renal masses requires accurate prediction of postoperative eGFR. METHODS: Patients who underwent RN or PN for a single renal mass at Xijing Hospital between 2008 and 2022 were retrospectively included. Preoperative split rGFR was evaluated using technetium-99 m-diethylenetriaminepentaacetic acid (Tc-99 m DTPA) renal dynamic imaging, and the postoperative short-term (< 7 days) and long-term (3 months to 5 years) eGFRs were assessed. Linear mixed-effect models were used to predict eGFRs, with marginal R2 reflecting predictive ability. RESULTS: After excluding patients with missing follow-up eGFRs, the data of 2251 (RN: 1286, PN: 965) and 2447 (RN: 1417, PN: 1030) patients were respectively included in the long-term and short-term models. Two models were established to predict long-term eGFRs after RN (marginal R2 = 0.554) and PN (marginal R2 = 0.630), respectively. Two other models were established to predict short-term eGFRs after RN (marginal R2 = 0.692) and PN (marginal R2 = 0.656), respectively. In terms of long-term eGFRs, laparoscopic and robotic surgery were superior to open surgery in both PN and RN. CONCLUSIONS: We developed novel tools for predicting short-term and long-term eGFRs after RN and PN based on split rGFR that can help in preoperative decision-making.

Epidemiology of extrapulmonary tuberculosis in central Guangxi from 2016 to 2021.

The burden of extrapulmonary tuberculosis (EPTB) has gradually increased in recent years, but not enough epidemiological data is available from central Guangxi. To better understand the epidemiology of EPTB in central Guangxi and identify risk factors associated with them, we retrospectively investigated the epidemiology of tuberculosis (TB), especially EPTB, among patients admitted to the Chest Hospital of Guangxi Zhuang Autonomous Region between 2016 and 2021. We excluded those infected with both pulmonary tuberculosis (PTB) and EPTB, reported the proportion and incidence of PTB or EPTB, and compared the demographic characteristics and risk factors of EPTB and PTB cases using univariate and multivariate logistic regression models. Among 30,893 TB patients, 67.25% (20,774) had PTB and 32.75% (10,119) had EPTB. Among EPTB, pleural, skeletal, lymphatic, pericardial, meningeal, genitourinary, intestinal, and peritoneal TB accounted for 49.44%, 27.20%, 8.55%, 4.39%, 3.36%, 1.48%, 0.87%, and 0.79%, respectively. Patients who were younger (age < 25), from rural areas, Zhuang and other ethnic groups, and diagnosed with anemia and HIV infection were more likely to develop EPTB. However, patients with diabetes and COPD were less likely to have EPTB. From 2016 to 2021, the proportion of PTB cases decreased from 69.73 to 64.07%. The percentage of EPTB cases increased from 30.27 to 35.93%, with the largest increase in skeletal TB from 21.48 to 34.13%. The epidemiology and risk factors of EPTB in central Guangxi are different from those of PTB. The incidence of EPTB is increasing and further studies are needed to determine the reasons for it.

Fine particles removal of pyrolysis gasification flue gas from rural domestic waste: Laboratory research, molecular dynamics simulation, and applications.

Chinese rural domestic waste has increased considerably with the modernization of agriculture and urbanization. Pyrolysis gasification is a common high-temperature waste treatment method. However, this method is usually accompanied by a large amount of particle emission. In this study, a rural domestic waste pyrolysis gasification station in Gansu Province, Northwest China, was selected for research. The particle emission characteristics of this station were analyzed, and the results showed that the original particle removal technologies were inefficient in fine particles. Hence, a new method of fine particle treatment, i.e., Cloud-Air-Purifying (CAP) technology, was explored herein. In CAP, fine particles grow in size via heterogeneous condensation in a supersaturated water vapor environment and are then collected efficiently using a supergravity field. A laboratory-scale pyrolysis gasifier and CAP equipment were built. Moreover, the CAP removal efficiency for particles generated from four typical rural domestic waste categories was studied. The results showed that CAP technology considerably increased the efficiency of fine particle removal. However, the removal efficiency for particles released owing to the incineration of wood was only ∼75%. This was because the tar substances formed during wood pyrolysis were attached to the surface of escaping particles, which led to a decrease in their hydrophilicity and particle condensation growth. To address this issue, the improvement in particle hydrophilicity using different surfactants was studied via molecular dynamic simulations. When the increase in water molecule adsorption, surface polarity, and the solid-liquid interaction energy for different surfactants were compared, alkylphenol ethoxylate (OP10) proved to be the most effective surfactant. Finally, the improved CAP technology combined with OP10 was applied to the on-site pyrolysis gasification flue gas treatment. Long term monitoring of the proposed technology revealed that particle removal efficiency remained >94%, exhibiting excellent fine particle removal. The successful application of the proposed technology demonstrates its potential for further application.

Ultrarapid Nanomanufacturing of High-Quality Bimetallic Anode Library toward Stable Potassium-Ion Storage.

Bimetallic alloy nanomaterials are promising anode materials for potassium-ion batteries (KIBs) due to their high electrochemical performance. The most well-adopted fabrication method for bimetallic alloy nanomaterials is tube furnace annealing (TFA) synthesis, which can hardly satisfy the trade-off among granularity, dispersity and grain coarsening due to mutual constraints. Herein, we report a facile, scalable and ultrafast high-temperature radiation (HTR) method for the fabrication of a library of ultrafine bimetallic alloys with narrow size distribution (≈10-20 nm), uniform dispersion and high loading. The metal-anchor containing heteroatoms (i.e., O and N), ultrarapid heating/cooling rate (≈103  K s-1 ) and super-short heating duration (several seconds) synergistically contribute to the successful synthesis of small-sized alloy anodes. As a proof-of-concept demonstration, the as-prepared BiSb-HTR anode shows ultrahigh stability indicated by negligible degradation after 800 cycles. The in situ X-ray diffraction reveals the K+ storage mechanism of BiSb-HTR. This study can shed light on the new, rapid and scalable nanomanufacturing of high-quality bimetallic alloys toward extended applications of energy storage, energy conversion and electrocatalysis.

Rosuvastatin Slows Progression of Carotid Intima-Media Thickness: The METEOR-China Randomized Controlled Study.

BACKGROUND: Atherosclerosis is the leading cause of cardiovascular disease worldwide, including in China. Primary prevention, through lipid-lowering, could avert development of atherosclerosis. Carotid intima-media thickness (CIMT) is a well-validated measure of atherosclerosis used in intervention studies as the primary outcome and alternative end point for cardiovascular disease events. METHODS: This randomized, double-blind, placebo-controlled, multicenter, parallel-group study assessed the effects of rosuvastatin 20 mg/d compared with placebo on progression of CIMT over 104 weeks in Chinese people with subclinical atherosclerosis. The primary end point was the annualized rate of change in mean of the maximum CIMT measurements taken 7× over the study period from each of 12 carotid artery sites (near and far walls of the right and left common carotid artery, carotid bulb, and internal carotid artery). Secondary end points included CIMT changes at different artery sites and lipid-parameter changes. Safety was also assessed. RESULTS: Participants were randomized (1:1) to receive rosuvastatin (n=272) or placebo (n=271). Baseline characteristics were well balanced between groups. The change in mean of the maximum CIMT of the 12 carotid sites was 0.0038 mm/y (95% CI, -0.0023-0.0100) for the rosuvastatin group versus 0.0142 mm/y (95% CI, 0.0080-0.0204) for the placebo group, with a difference of -0.0103 mm/y (95% CI, -0.0191 to -0.0016; P=0.020). For the CIMT secondary end points, the results were generally consistent with the primary end point. There were clinically relevant improvements in lipid parameters with rosuvastatin. We observed an adverse-event profile consistent with the known safety profile of rosuvastatin. CONCLUSIONS: Rosuvastatin 20 mg/d significantly reduced the progression of CIMT over 2 years in Chinese adults with subclinical atherosclerosis and was well tolerated. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02546323.

Different N-Glycosylation Sites Reduce the Activity of Recombinant DSPAα2.

Bat plasminogen activators α2 (DSPAα2) has extremely high medicinal value as a powerful natural thrombolytic protein. However, wild-type DSPAα2 has two N-glycosylation sites (N185 and N398) and its non-human classes of high-mannose-type N-glycans may cause immune responses in vivo. By mutating the N-glycosylation sites, we aimed to study the effect of its N-glycan chain on plasminogen activation, fibrin sensitivity, and to observe the physicochemical properties of DSPAα2. A logical structure design was performed in this study. Four single mutants and one double mutant were constructed and expressed in Pichia pastoris. When the N398 site was eliminated, the plasminogen activator in the mutants had their activities reduced to ~40%. When the N185 site was inactivated, there was a weak decrease in the plasminogen activation of its mutant, while the fibrin sensitivity significantly decreased by ~10-fold. Neither N-glycosylation nor deglycosylation mutations changed the pH resistance or heat resistance of DSPAα2. This study confirms that N-glycosylation affects the biochemical function of DSPAα2, which provides a reference for subsequent applications of DSPAα2.

Integrated metabolomic and transcriptomic analyses of regulatory mechanisms associated with uniconazole-induced dwarfism in banana.

BACKGROUND: Uniconazole is an effective plant growth regulator that can be used in banana cultivation to promote dwarfing and enhance lodging resistance. However, the mechanisms underlying banana dwarfing induced by uniconazole are unknown. In uniconazole-treated bananas, gibberellin (GA) was downregulated compared to the control groups. An integrative analysis of transcriptomes and metabolomes was performed on dwarf bananas induced by uniconazole and control groups. The key pathways involved in uniconazole-induced dwarfism in banana were determined according to the overlap of KEGG annotation of differentially expressed genes and (DEGs) differential abundant metabolites (DAMs). RESULTS: Compared with the control groups, the levels of some flavonoids, tannins, and alkaloids increased, and those of most lipids, amino acids and derivatives, organic acids, nucleotides and derivatives, and terpenoids decreased in uniconazole-treated bananas. Metabolome analysis revealed the significant changes of flavonoids in uniconazole-treated bananas compared to control samples at both 15 days and 25 days post treatment. Transcriptome analysis shows that the DEGs between the treatment and control groups were related to a series of metabolic pathways, including lignin biosynthesis, phenylpropanoid metabolism, and peroxidase activity. Comprehensive analysis of the key pathways of co-enrichment of DEGs and DAMs from 15 d to 25 d after uniconazole treatment shows that flavonoid biosynthesis was upregulated. CONCLUSIONS: In addition to the decrease in GA, the increase in tannin procyanidin B1 may contribute to dwarfing of banana plants by inhibiting the activity of GA. The increased of flavonoid biosynthesis and the change of lignin biosynthesis may lead to dwarfing phenotype of banana plants. This study expands our understanding of the mechanisms underlying uniconazole-induced banana dwarfing.

Ultrafast Porous Carbon Activation Promises High-Energy Density Supercapacitors.

Activated porous carbons (APCs) are traditionally produced by heat treatment and KOH activation, where the production time can be as long as 2 h, and the produced activated porous carbons suffer from relatively low specific surface area and porosity. In this study, the fast high-temperature shock (HTS) carbonization and HTS-KOH activation method to synthesize activated porous carbons with high specific surface area of ≈843 m2 g-1 , is proposed. During the HTS process, the instant Joule heating (at a heating speed of ≈1100 K s-1 ) with high temperature and rapid quenching can effectively produce abundant pores with homogeneous size-distribution due to the instant melt of KOH into small droplets, which facilitates the interaction between carbon and KOH to form controllable, dense, and small pores. The as-prepared HTS-APC-based supercapacitors deliver a high energy density of 25 Wh kg-1 at a power density of 582 W kg-1 in the EMIMBF4 ionic liquid. It is believed that the proposed HTS technique has created a new pathway for manufacturing activated porous carbons with largely enhanced energy density of supercapacitors, which can inspire the development of energy storage materials.

Reduced motor cortex GABABR function following chronic alcohol exposure.

The GABAB receptor (GABABR) agonist baclofen has been used to treat alcohol and several other substance use disorders (AUD/SUD), yet its underlying neural mechanism remains unclear. The present study aimed to investigate cortical GABABR dynamics following chronic alcohol exposure. Ex vivo brain slice recordings from mice chronically exposed to alcohol revealed a reduction in GABABR-mediated currents, as well as a decrease of GABAB1/2R and G-protein-coupled inwardly rectifying potassium channel 2 (GIRK2) activities in the motor cortex. Moreover, our data indicated that these alterations could be attributed to dephosphorylation at the site of serine 783 (ser-783) in GABAB2 subunit, which regulates the surface expression of GABABR. Furthermore, a human study using paired-pulse-transcranial magnetic stimulation (TMS) analysis further demonstrated a reduced cortical inhibition mediated by GABABR in patients with AUD. Our findings provide the first evidence that chronic alcohol exposure is associated with significantly impaired cortical GABABR function. The ability to promote GABABR signaling may account for the therapeutic efficacy of baclofen in AUD.

First Report of Colletotrichum fioriniae Causing Anthracnose on Rhododendron delavayi in China.

Rhododendron delavayi Franch, a member of Ericaceae family, is globally famous for its garden flowers with significant ornamental value (Liu et al., 2020). In July 2020 and 2021, a disease survey of R. delavayi groves was conducted in Baili Azalea Forest Area (N27°10'-27°20', E 105°04'-106°04'). We arbitrarily selected an area with around 280 R. delavayi trees covering 2.5 hectares in R. delavayi grove where 20-35% of leaves showed symptoms of anthracnose. Typical symptoms included elliptical to irregularly shaped brown lesions on leaves and masses of black dots clustered on it. About 30 pieces of leaves with anthracnose lesions were collected. A few black dots were picked from the lesions with a sterilized needle, plated on water agar and incubated at 25℃ for 12 h to observe spore germination (Fang, 2007). Then the germinated spores were transferred onto PDA medium for further purification and morphological observation. Fourteen single-spore isolates with similar morphology were obtained. The surface of the colony was white or gray and spongy; the edge was smooth; and the back side was pinkish brown after 7 days of growth on PDA. Conidia were spindle-shaped, transparent, 11.1-16.6×3.6-4.9 µm (n=50). Appressorium from conidia was nearly ovate or proximate, brown or dark brown in color, 4.3-10.3 ×3.2-7.6 µm (n=50). These characteristics are consistent with Colletotrichum fioriniae reported by Shivas and Tan (2009). DNA was extracted from a representative isolate MYDJ12. The internal transcribed spacer region (ITS), the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ß-tubulin (TUB), actin (ACT), and chitin synthase 1 (CHS-1) genes were amplified using primer pairs described by Damm et al. (2012). The sequences were deposited in GenBank with accession number MW692854 (ITS), MW727518 (GAPDH), MW727519 (TUB2), MW727520 (ACT), and MW727521 (CHS-1). BLASTN searches of the ITS, GADPH, TUB2, ACT and CHS-1 genes revealed 100% (540/540 nucleotides), 100% (254/254 nucleotides), 99.38% (4488/491 nucleotides), 98.77% (242/245 nucleotides) and 100% (282/282 nucleotides) homology with those of C. fioriniae CBS:128517T in GenBank (NR_111747, JQ948622, JQ949943, JQ949613 and JQ948953 respectively). The phylogenetic tree showed the isolate MYDJ12 to cluster with C. fioriniae CBS:128517T. Finally, two-year old R. delavayi plants (n=5) were inoculated by wounding with a syringe needle and placing 10 µL of spore suspension (106 spores per mL) of the isolate MYDJ12 on three leaves per plant. Control leaves were inoculated with sterile water. The experiment was conducted twice. Inoculated leaves were wrapped in parafilm tape and then the plants were placed in a greenhouse at 25°C with high relative humidity (90 to 95%). Seven days after incubation, brown lesions appeared, similar to those observed in the grove. Black dots clustered on the lesions after 15 days. Re-isolation was conducted 20 days after inoculation. From all the five inoculated plants, similar symptoms were observed, and the same pathogen was re-isolated. One of the isolates was selected for morphological observation and multi-gene (ITS, GAPDH, ACT, TUB2 and CHS-1) analysis indicated the reisolated fungus to be C. fioriniae. No fungal pathogens were isolated from mock inoculated plants. This study can provide effective management and useful information for the control of this disease on R. delavayi in Baili Azalea Forest Area. References: Damm, U., et al. 2012. Stud Mycol 73: 37. Fang, Z. D. 2007. Research Methods of Plant Diseases (Third edition). China Agriculture Press. Liu, J., et al. 2020. Mitochondrial DNA B 5:37. Shivas, R, G; Tan, Y, P. 2009. Fungal Divers 39:111.

Leaf spot on Photinia × fraseri caused by Neopestalotiopsis asiatica in China.

Photinia × fraseri is a well-known evergreeen ornamental tree. Owing to its flower-like red leaves and its ability to tolerate stressful environments, P. fraseri is widely cultured as a fast-growing hedge in southern China. From July to September in 2021, a disease with symptoms similar to leaf spot was extensively observed on P. fraseri in Daozhen county (28° 51 'N, 107° 57 'E), Zunyi, Guizhou province, China. About 500 plants were surveyed and the incidence of leaf spot on P. fraseri leaves was 35% to 70%, significantly reducing the ornamental and economic value. The symptomatic leaves displayed irregular, watery dark brown lesions with black conidiomata in gray centers, and 10 symptomatic leaves were collected from 10 trees. After surface sterilization (0.5 min in 75% ethanol and 2 min in 3% NaOCl, washed three times with sterilized distilled water) (Fang 2007), small pieces of symptomatic leaf tissue (0.2 × 0.2 cm) were plated on potato dextrose agar (PDA) and incubated at 25°C for about 7 days. Three single-spore isolates, GZAAS 21-0327, GZAAS 21-0328 and GZAAS 21-0329, were obtained, which were identical in morphology and molecular analysis. Therefore, the representative isolate GZAAS 21-0328 was used for further study. The pathogenicity of GZAAS 21-0328 was tested through a pot assay. Ten healthy plants were scratched with a sterilized needle on the leaves. Plants were inoculated by spraying a spore suspension (106 spores mL-1) of GZAAS 21-0328 onto leaves until runoff, and the control leaves sprayed with sterile water. The plants were maintained at 28°C with high relative humidity (95%) in a growth chamber. The pathogenicity test was carried out three times (Fang 2007). The symptoms developed on all inoculated leaves but not on the control leaves. The lesions were first visible 72 h after inoculation, and typical lesions similar to those observed on field plants appeared after 15 days. The same fungus was reisolated and identified based on the morphological characterization and molecular analyses (ITS, TUB and TEF) from the infected leaves but not from the noninoculated leaves. Results of pathogenicity experiments of isolated fungi fulfilled Koch's postulates. Fungal colonies on PDA were villiform, creamy-white and sparse aerial mycelium on the surface with black, gregarious conidiomata. The conidia were fusoid, ellipsoid, straight to slightly curved, 4-septate, septa darker than the rest of the cell, and 23.0 (21.0 to 27.0) × 6.0 (5.0 to 7.0) µm (n=50). The morphological features were consistent with the descriptions of Neopestalotiopsis asiatica Maharachch. & K.D. Hyde (Maharachchikumbura et al. 2012; Maharachchikumbura et al. 2014; Farr et al. 2022). The pathogen was confirmed to be N. asiatica by amplification and sequencing of the internal transcribed spacer region (ITS), the partial ß-tubulin (TUB) and partial translation elongation factor 1-alpha (TEF) genes using primers ITS4/ITS5, T1/Bt-2b and EF1-728F/EF-2, respectively (Maharachchikumbura et al. 2014). The sequences of PCR products were deposited in GenBank with accession numbers OK563071 (ITS), OK584020 (TUB) and OK663023 (TEF). BLAST searches of the obtained sequences revealed 100% (482/482 nucleotides), 99.05% (419/421 nucleotides), and 99.33% (891/897 nucleotides) homology with those of N. asiatica in GenBank (JX398983, JX399018 and JX399049, respectively). Phylogenetic analysis (MEGA 6.0) using the maximum likelihood method placed the isolate GZAAS 21-0328 in a well-supported cluster with N. asiatica. The pathogen was thus identified as N. asiatica based on the morphological characterization and molecular analyses. To our knowledge, this is the first report of leaf spot on P. fraseri caused by N. asiatica in China. This study provides valuable information for the identification and control of the leaf spot on Photinia × fraseri.