DNA methylation variation is crucial to restore adventitious rooting ability during in vitro shoot culture-induced rejuvenation in apple rootstock.

In vitro shoot culture has been widely used for restoring adventitious rooting ability in rooting recalcitrant woody perennial species for the past few decades, but its molecular mechanism is largely uncovered. DNA methylation is an essential epigenetic mark that participates in many biological processes. Recent reports suggested a role of DNA methylation in vitro culture in plants. In this study, we characterized the single-base resolution DNA methylome and transcriptome of adult and in vitro shoot culture-induced rejuvenation cuttings of apple rootstock M9T337. We found a global decrease in DNA methylation during rejuvenation, which may be correlated with increased expression of DNA demethylase genes and decreased expression of DNA methyltransferase genes. We additionally documented DNA hypomethylation in 'T337'_R in gene protomer associated with higher transcript levels of several adventitious rooting-related genes. The application of a DNA methylation inhibitor (5-azacytidine) enhanced the adventitious rooting ability and the expression level of adventitious rooting-related genes, such as, MdANT, MdMPK3, MdABCB21, MdCDC48, MdKIN8B, pri-MdMIR156a5 and pri-MdMIR156a12. Together, the DNA hypomethylation is critical for the rejuvenation-dependent adventitious rooting ability in apple rootstock. In addition, increased DNA methylation was also found in thousands of genes in 'T337'_R. We additionally documented that DNA hypermethylation is required for inhibition of adventitious rooting-repressed genes, such as MdGAD5a, encoding glutamate decarboxylase, which can catalyze glutamate decarboxylated to form γ-aminobutyric acid (GABA). Our results revealed that in vitro shoot culture-dependent DNA methylation variation plays important roles in adventitious rooting in apple rootstock.

Identification of a novel waikavirus infecting Pittosporum tobira in China.

A novel waikavirus, tentatively named "Pittosporum tobira waikavirus" (PtWV), was identified in Pittosporum tobira plants exhibiting mosaic and ringspot symptoms on foliage in Yunnan, China. The full-length genomic sequence was determined by high-throughput sequencing and rapid amplification of cDNA ends. The genome of PtWV is 12,709 nt in length and has a large open reading frame (ORF) of 11,010 nt, encoding a polyprotein, and a small ORF that encodes a 13.2-kDa bellflower vein chlorosis virus (BVCV)-like protein. Phylogenetic analysis and sequence alignment revealed that PtWV is closely related to actinidia yellowing virus 1 (AcYV1), which shares the highest amino acid (aa) sequence similarity (50.1% identity) in the Pro-RdRp region. To the best of our knowledge, this is the first report of a novel waikavirus in P. tobira.

Arthroscopic Treatment of Popliteal Cyst Through the Posterior Portal: A Comprehensive Clinical Study.

BACKGROUND A popliteal cyst, often perceived as benign, poses potential harm and symptoms. This study focused on arthroscopic treatment through the posterior knee portal at our medical center, aiming to assess its efficacy, safety, and long-term outcomes compared to traditional methods. MATERIAL AND METHODS A retrospective analysis of 20 patients (9 males and 11 females) with symptomatic popliteal cysts (January 2020 to December 2022) undergoing arthroscopic treatment via the posterior knee portal was conducted. Data on demographics, clinical presentation, preoperative imaging, surgical techniques, intraoperative findings, and postoperative Rauschning and Lindgren scores were collected and analyzed. RESULTS With a mean follow-up of 13.6 months (range: 12 to 36 months), all patients had associated intra-articular lesions and were treated. Degenerative cartilage damage was most common (65.0% of cases). The Rauschning and Lindgren score significantly improved after surgery (P<0.05), with no recurrence evident on MRI in any patients. CONCLUSIONS Arthroscopic treatment through the posterior knee portal has good potential for popliteal cyst management. This minimally invasive approach offers benefits such as direct visualization, precise cyst excision, and concurrent treatment of intra-articular pathologies.

Exposure to heavy metal elements may significantly increase serum prostate-specific antigen levels with overdosed dietary zinc.

BACKGROUND: Serum prostate-specific antigen (PSA) is a primary metric for diagnosis and prognosis of prostate cancer (PCa). Exposure to heavy metals, such as lead, cadmium, mercury, and zinc can impact PSA levels in PCa patients. However, it is unclear whether this effect also occurs in men without PCa, which may lead to the overdiagnosis of PCa. METHOD: Data on a total of 5089 American men who had never been diagnosed with PCa were obtained from the National Health and Nutrition Examination Survey performed from 2003-2010. The relationship between serum PSA levels (dependent variable) and concentrations of lead (µmol/L), cadmium (nmol/L), and mercury (µmol/L) were investigated with dietary zinc intake being used as a potential modifier or covariate in a weighted linear regression model and a generalized additive model. A series of bootstrapping analyses were performed to evaluate sensitivity and specificity using these models. RESULTS: Regression analyses suggested that, in general, lead, cadmium, or mercury did not show an association with PSA levels, which was consistent with the results of the bootstrapping analyses. However, in a subgroup of participants with a high level of dietary zinc intake (≥14.12 mg/day), a significant positive association between cadmium and serum PSA was identified (1.06, 95% CI, P = 0.0268, P for interaction=0.0249). CONCLUSIONS: With high-level zinc intake, serum PSA levels may rise in PCa-free men as the exposure to cadmium increases, leading to a potential risk of an overdiagnosis of PCa and unnecessary treatment. Therefore, environmental variables should be factored in the current diagnostic model for PCa that is solely based on PSA measurements. Different criteria for PSA screening are necessary based on geographical variables. Further investigations are needed to uncover the biological and biochemical relationship between zinc, cadmium, and serum PSA levels to more precisely diagnose PCa.

Mechanism of Dendrobium Nobile Polysaccharide Inhibition of Ferroptosis in Rats with Spinal Cord Injury.

BACKGROUND: It has been reported that ferroptosis participates in the pathophysiological mechanism of spinal cord injury (SCI). Our preliminary experiments verified that dendrobium nobile polysaccharide (DNP) improved the behavioral function of SCI rats. Therefore, the purpose of this study was to examine the role of DNP on ferroptosis and its neuroprotective mechanism in SCI rats. METHODS: Adult female sprague dawley (SD) rats were exposed to SCI by Allen's method, followed by an intragastric injection of 100 mg/kg DNP per day for 2 weeks. Behavioral features were verified by the Basso-Beattie-Bresnahan (BBB) scale and footprint evaluation. Iron content and glutathione (GSH) were assessed spectrophotometrically. Mitochondrial morphology was examined by transmission electron microscopy. The expression of ferroptosis-related genes, including System Xc- light chain (xCT), G-rich RNA sequence binding Factor 1 (GRSF1) and glutathione peroxidase 4 (Gpx4), was examined by real-time polymerase chain reaction (PCR) and western blot. The spinal cavity was defined using hematoxylin-eosin (HE) staining, and neuronal modifications were detected by immunofluorescence. RESULTS: Compared with the SCI group, the BBB score of rats in the DNP group increased at 7 d, 14 d, 21 d, and 28 d. The differences between the two groups were statistically significant. At 12 h post-injury the iron content began to decrease. At 24 h post-injury the iron content decreased significantly in the DNP group. The morphological changes of the mitochondrial crest and membrane in the DNP group were ameliorated within 24 h. Compared with the sham group, the expression of xCT, GSH, Gpx4, and GRSF1 were significantly reduced after SCI. After DNP treatment, the expression of xCT, Gpx4, and GSH were higher. The tissue cavity area was significantly reduced and the amount of NeuN+ cells was increased in the DNP group at 14 d and 28 d after SCI. CONCLUSIONS: DNP facilitated the post-injury recovery in SCI rats via the inhibition of ferroptosis.

First Report of Powdery Mildew caused by Erysiphe astragali on Sphaerophysa salsula.

Sphaerophysa salsula (Pall.) DC., also known as Yang Liao Pao, belongs to the Leguminosae family and is the only existing species in the Sphaerophysa genus. S. salsula is tolerance to cold, high salt, and alkaline soil, it is widely cultivated in China as a forage crop, and used as a Chinese folk medicine to treat hypertension (Ma et al., 2002). In 2023, signs and symptoms similar to powdery mildew were found on S. salsula planted in Tumd left (40.515°N, 110.424°E), Baotou City, Inner Mongolia Autonomous Region, China. The white powdery substance covered 90% of the leaf area, and the infected plants showed weak growth and senescence. More than 80% of plants (n=200) had these powdery mildew-like symptoms. Hyphal appressoria are solitary, conidiophores have few branches and septa. Conidia are cylindrical to clavate, 25-32 µm long and 8-15 µm wide (n=30), conidia form single subapical germ tubes, straight to curved-sinuous, with swollen apex or distinctly lobed conidial appressorium. Based on these morphological characteristics, the fungus was tentatively identified as an Erysiphe sp. (Schmidt and Braun 2020). Fungal structures were isolated from diseased leaves, and genomic DNA of the pathogen was extracted using the method described by Zhu et al. (2022). The internal transcribed spacer (ITS) region was amplified by PCR using the primers PMITS1/PMITS2 (Cunnington et al. 2003) and the amplicon sequenced by Invitrogen (Shanghai, China). The powdery mildew strain, named as KMD (GenBank accession no.: PP267067), showed an identity of 100% (645/645bp) with Erysiphe astragali, a powdery mildew reported on Astragalus glycyphyllos in Golestan, Iran (GenBank: OP806834) and identity of 99.6% (643/645bp) with Erysiphe astragali (GenBank: MW142495), a powdery mildew reported on A. scaberrimus in Inner Mongolia, China (Sun et al. 2023). Pathogenicity tests were conducted by brushing the conidia from infected S. salsula leaves onto leaves of four healthy plants, while four control plants were brushed in the same manner. All the treated plants were placed in separate growth chambers maintained at 19°C and 65% humidity, with a 16 h light/8 h dark photoperiod. Nine days after inoculation, the treated plants showed powdery mildew symptoms, while the control plants remained asymptomatic. The same results were obtained for two repeated pathogenicity experiments. The powdery mildew fungus was reisolated and identified as E. astragali based on morphological and molecular analysis, thereby fulfilling Koch's postulates. No report on the occurrence of powdery mildew on S. salsula plants has been found previously. The occurrence of this destructive powdery mildew may adversely affect the cultivation of S. salsula. Identifying the pathogen of powdery mildew will support future efforts to control and manage powdery mildew on S. salsula.

First Report of Leek Yellow Stripe Virus Infecting Allium cepa in China.

Onion (Allium cepa), a member of the genus Allium, is widely cultivated throughout the world including China (Zhang et al. 2022). In July 2022, stunted onion (A. cepa 'Weiwang') plants showing typical symptoms of yellow stripe and leaves distortion (Fig. S1) were observed in a vegetable garden in Hohhot, Inner Mongolia, China. The garden is approximately 0.24 ha with around 20,000 onion plants, out of which 140 plants were symptomatic. Diagnosis of the symptomatic plants using negative stain electron microscopy revealed the association of long flexuous virus particles measuring about 11 to 12 nm × 820 to 1000 nm (Fig. S2), which was suggestive of the presence of potyvirus (Chen et al. 2002). Subsequently, the pathogen was identified as the leek yellow stripe virus through RT-PCR combined with Sanger sequencing as described below. The total RNA of each sample was extracted using the MiniBEST plant RNA extraction kit (TaKaRa, Dalian, China), serving as template for synthesis of cDNA using the ABScriptIII RT master mix (ABclonal Biotechnology, Wuhan, China). We then amplified a fragment at the 3' terminus of LYSV using a M5 Hiper superluminal mix (Mei5 Biotechnology, Beijing, China) with the primer pair LYSV-F / LYSV-R (Santosa and Ertunc 2020) which flank the partial NIb gene, the complete coat protein gene and partial 3' untranslated region of LYSV. A unique PCR product of about 1 kb was seen for 10 out of the 140 samples. Five out of the 10 PCR products were randomly selected and cloned using a Zero Background pTOPO-TA cloning kit (Aidlab Technologies, Beijing, China) and E. coli JM109 competent cells were then transformed. Positive colonies were screened by PCR detection of the insert fragments using the primers LYSV-F/-R, and the inserts were sequenced at BGI Genomics (Beijing) using the M13(-21) Forward and M13 Reverse primers. All the obtained sequences were 1032 nt in length, and shared nucleotide sequence identities of 99.2% to 100% (two out of the five sequences were identical to each other). The query sequences were submitted to BLASTn to retrieve homologous sequences from NCBI GenBank databases, and the results showed that the four sequences were homologous to LYSV, suggesting the occurrence of LYSV on onions in Inner Mongolia, China. The sequences were then deposited in GenBank under accession numbers of OQ969953-56, named LYSV isolate Hohhot-1, -2, -3, and -4. In comparison with other published LYSV isolates, the LYSV Hohhot-1, -2, -3, and -4 had the highest nucleotide sequence identity of 87.23%, 86.97%, 87.33%, and 87.23% with LYSV G66 (GenBank accession no. MN059493), respectively, which infects garlic in China. Phylogeny analysis was performed based on 41 complete sequences of the CP gene of LYSV, including the four in this work and another 37 from GenBank of which six isolates were discovered in onions in Turkey (MN070124, MN070126, MN070130, MN070131, MN864794 and MN864795) and the others 31 isolates were from garlics or leeks in 15 different countries (Argentina, Australia, Brazil, China, Ethiopia, Germany, India, Iran, Japan, Mexico, Netherlands, New Zealand, Serbia, South Korea, and Spain), while the CP gene of onion yellow dwarf virus (AJ510223) was employed as an outgroup reference. The tree was reconstructed using the neighbor-joining method of MEGA11 with a bootstrap value of 1,000 replicates. On the tree (Fig. S3), the LYSV Hohhot-1, -2, -3, and -4 were closely related to each other and were distinct from other LYSV isolates including the six isolates in onions in Turkey, suggesting a specific genetic variation of the LYSV isolates in Hohhot. According to Santosa et al. (2023), LYSV Hohhot-1, -2, -3, and -4 were within the S-type lineage. This was the first record of LYSV infecting onions in China, expanding the natural host range of LYSV in China, which offered important information for the management of onion diseases.

Powdery Mildew of Xanthium strumarium Caused by Podosphaera xanthii in central China.

Xanthium strumarium, known as cocklebur, is an annual herb and has been used in traditional Chinese medicine. In October 2020, powdery mildew-like disease signs and symptoms were observed on X. strumarium grown in a crop field, Xinxiang city, Henan Province, China (35.36076° N, 113.93467° E). The specimen (PX-XS2023) was stored in Xinxiang Key Laboratory of Plant Stress Biology. White colonies in irregular or coalesced circular shaped-lesions were abundant on both ad- and abaxial surfaces of leaves and covered up to 99 % of the leaf area. Some of the infected leaves were senesced. More than 70 % of plants (n = 130) exhibited these signs and symptoms. Conidiophores were straight or slightly curved, 55 to 160 × 11 to 13 µm composed of foot-cells, shorter cells and conidia. Conidia were ellipsoid to oval, 29 to 40 × 14 to 20 µm (n = 50), with a length/width ration of 2.0 to 2.5, containing fibrosin bodies. Dark brown to black chasmothecia were found on infected leaves. The appendages were mycelium-shaped and at the base of scattered or gregarious chasmothecia (n = 50, 70 to 120 µm in diameter). Asci were 55 to 80 × 50 to 65 µm (n=30). These morphological characteristics were consistent with those of Podosphaera xanthii (Braun and Cook 2012). The internal transcribed spacer (ITS) region and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) region of the fungus (PX-XS2023) were amplified and sequenced with primers ITS1/ITS4 (White et al. 1990) and GAPDH1/GAPDH3R (Bradshaw et al. 2022) according to a previously reported method (Zhu et al. 2022). The resulting sequences were respectively deposited into GenBank (Accession No. MW300956 and PP236083). BLASTn analysis indicated that the sequences were respectively 99.82 % (564/565) and 100% (272/272) identical to P. xanthii (MT260063 and ON075658). The phylogenetic analysis indicated that the strain PX-XS2023 and P. xanthii were clustered into a same branch. Therefore, the causal agent of powdery mildew on X. strumarium was P. xanthii. To conduct pathogenicity assays, mature leaves of five healthy X. strumarium (height in 50 centimeters) were inoculated with fungal conidia by gently pressing surfaces of infested leaves onto leaves of healthy plants (Zhu et al. 2020). Five untreated plants served as controls. The controls and inoculated plants were separately maintained in greenhouses (humidity, 60%; light/dark, 16 h/8 h; temperature, 18°C). Eight days post-inoculation, signs of powdery mildew were detectable on inoculated plants, however, the controls were asymptomatic. Thus, the fungal pathogen was morphologically and molecularly identified and confirmed as P. xanthii. This powdery mildew caused by P. xanthii was previously reported on X. strumarium in Korea, Russia and India (Farr and Rossman, 2021). In addition, P. xanthii was recorded on X. strumarium in Xinjiang Province, China (Tai 1979). However, this is the first report of P. xanthii on X. strumarium in central China, where is around 3000 km away from Xinjiang Province with geographically differences. The sudden presence of powdery mildew caused by P. xanthii may adversely affect plant health and thus reduce medical value of X. strumarium. Therefore, the identification and confirmation of P. xanthii infecting X. strumarium enhance the knowledge on the hosts of this pathogen in China and will provide fundamental information for disease control in the future.

Efficacy of mesenchymal stromal cells intraspinal transplantation for patients with different degrees of spinal cord injury: A systematic review and meta-analysis.

BACKGROUND AIMS: Several studies have reported that mesenchymal stromal cells (MSCs) may improve neurological functions in patients with spinal cord injury (SCI). In this study, we conducted a systematic review and meta-analysis to summarize the effects of MSC treatment on different degrees of severity of SCI. METHODS: Systematic searching of studies reporting outcomes of MSCs on specific injury severities of patients with SCI was performed in The National Library of Medicine (MEDLINE), Embase and Cochrane for published articles up to the 6 July 2022. Two investigators independently reviewed the included studies and extracted the relevant data. The standardized mean differences of American Spinal Injury Association (ASIA) motor score, ASIA light touch scores, ASIA pinprick scores and the Barthel index between baseline and follow-ups were pooled. RESULTS: A total of eight studies were included. A large majority focused on patients with ASIA grade A classification. The pooled mean differences of ASIA motor scores, ASIA light touch scores, ASIA pinprick scores and the Barthel index were -2.78 (95% confidence interval [CI] -5.12 to -0.43, P = 0.02), -18.26 (95% CI -26.09 to -10.43, P < 0.01), -17.08 (95% CI -24.10 to -10.07, P < 0.01) and -4.37 (95% CI -10.96 to 2.22, P = 0.19), respectively. CONCLUSIONS: MSC transplantation was a significantly effective therapy for patients with SCI with ASIA grade A. In the future, further studies are warranted to confirm the potential beneficial effects of MSC therapy.

Genomic characterization of a novel torradovirus infecting Arctium lappa L. in China.

Burdock (Arctium lappa L.) is not only a popular vegetable crop but also an important medicinal plant. In burdock plants with symptoms of leaf mosaic, a novel torradovirus tentatively named "burdock mosaic virus" (BdMV) was identified by high-throughput sequencing. The complete genomic sequence of BdMV was further determined using RT-PCR and the rapid amplification of cDNA ends (RACE) method. The genome is composed of two positive-sense single-stranded RNAs. RNA1 (6991 nt) encodes a polyprotein of 2186 aa, and RNA2 (4700 nt) encodes a protein of 201 aa and a polyprotein of 1212 aa that is predicted to be processed into one movement protein (MP) and three coat proteins (CPs). The Pro-Pol region of RNA1 and the CP region of RNA2 shared the highest amino acid sequence identity of 74.0% and 70.6%, respectively, with the corresponding sequences of lettuce necrotic leaf curl virus (LNLCV) isolate JG3. Phylogenetic analysis based on the amino acid sequences of the Pro-Pol and CP regions showed that BdMV clustered with other non-tomato-infecting torradoviruses. Taken together, these results suggest that BdMV is a new member of the genus Torradovirus.

Occurrence of Powdery Mildew Caused by Erysiphe astragali on Astragalus scaberrimus in Inner Mongolia, China.

Astragalus scaberrimus Bunge, a perennial herb, is widely distributed in North and central China, Russia, and Mongolia (POWO, 2023). Due to its tolerance to drought, cold, high salt, low nutrients and alkaline soil, this plant is widely cultivated in China as a forage crop, for water and soil conservation, and for its medicinal properties (Meng, 2015). In 2022, powdery mildew-like signs and symptoms were seen on leaves of A. scaberrimuns cultivated on the campus of Inner Mongolia Agricultural University, Hohhot, Inner Mongolia China. White powder-like masses covered up to 99% of the leaf area with infected plants showing weak growth and senescence. More than 70% of plants (n = 180) exhibited these powdery mildew-infected symptoms. Conidiophores were 70-120 µm long (n = 20) and composed of a basal foot cell, followed by two cells and a conidium. Cylindrical- or ovoid-shaped conidia were 30-45µm long by 9-15 µm wide (n = 20). Brown or light-brown chasmothecia were 100-140 µm in diameter, with flexuous appendages. Based on these morphological characteristics, the fungus was tentatively identified as an Erysiphe sp. (Braun and Cook, 2012; Schmidt and Braun, 2020). Fungal structures were isolated from diseased leaves and genomic DNA of the pathogen was extracted utilizing the method described by Zhu et al. (2022). The internal transcribed spacer (ITS) region was amplified by PCR employing the primers PMITS1/PMITS2 (Cunnington et al., 2003) and the amplicon sequenced by Invitrogen (Shanghai, China). The sequence for the powdery mildew fungus (GenBank accession no.: MW142495) showed 100% identity (645/645 bp) with Erysiphe astragali, which was reported on A. glycyphyllos in Golestan province, Iran (accession no. OP806834). Pathogenicity tests were conducted by brushing the conidia from infected A. scaberrimus leaves onto leaves of four healthy plants, while, the four control plants were brushed in the same manner. All the treated plants were placed in separate growth chambers maintained at 19℃, 65% humidity, with 16 h light/8 h dark photoperiod. Nine days post inoculation, powdery mildew disease signs appeared on inoculated plants, whereas control plants remained asymptomatic. The same results were obtained for two repeated pathogenicity experiments. The powdery mildew fungus was reisolated and identified as E. astragali based on morphological and molecular analysis, thereby fulfilling Koch's postulates. E. astragali causing powdery mildew on A. glycyphyllus were previously reported in Germany with Genbank accesion number of MZ265150 and MZ265151 (Bradshaw et al., 2022). This, to our knowledge, is the first report of powdery mildew caused by E. astragali on A. scaberrimus. The severe occurrence of this destructive powdery mildew disease on A. scaberrimus may adversely affect the utility of the plant for soil conservation or cultivation for medicinal purposes. Identifying the causal agent of powdery mildew will support efforts for the future control and management of diseases on A. scaberrimus.

Adaptive Bidirectional Gray-Scale Center of Gravity Extraction Algorithm of Laser Stripes.

Aiming at the realization of fast and high-precision detection of the workpiece, an adaptive bidirectional gray-scale center of gravity extraction algorithm for laser stripes is proposed in this paper. The algorithm is processed in the following steps. Firstly, the initial image processing area is set according to the floating field of the camera's light stripe, followed by setting the adaptive image processing area according to the actual position of the light stripe. Secondly, the center of light stripe is obtained by using the method of combining the upper contour with the barycenter of the bidirectional gray-scale. The obtained center of the light stripe is optimized by reducing the deviation from adjacent center points. Finally, the slope and intercept are used to complete the breakpoint. The experimental results show that the algorithm has the advantages of high speed and precision and has specific adaptability to the laser stripes of the complex environment. Compared with other conventional algorithms, it greatly improves and can be used in industrial detection.

Occurrence of Powdery Mildew Caused by Erysiphe buhrii on Dianthus chinensis in Inner Mongolia, China.

Dianthus chinensis is widely cultivated for ornamental and medicinal use in China (Guo et al. 2017). The plant has been used in traditional Chinese medicine for the treatment of urinary problems such as strangury and diuresis (Han et al. 2015). In June and July 2020, powdery mildew-like signs and symptoms were seen on leaves of D. chinensis cultivated on the campus of Inner Mongolia Agricultural University, Hohhot city, Inner Mongolia Province, China. White powder-like masses occurred in irregular shaped lesions on both leaf surfaces and covered up to 50% of leaf area. Some infected leaves were deformed on their edges and some leaf senescence occurred. More than 40 % of plants (n = 180) exhibited these signs and symptoms. Conidiophores (n = 50) of the suspect fungus were unbranched and measured 70 to 140 µm long × 6 to 10 µm wide and had foot cells that were 25 to 48 µm long. Conidia (n = 50) were produced singly, elliptical to cylindrical shaped, 30 to 45 µm long × 12 to 19 µm wide, with length/width ratio of 2.0 to 3.2, and lacked fibrosin bodies. No chasmothecia were found. Based on these morphological characteristics, the fungus was tentatively identified as an Erysiphe sp. (Braun and Cook 2012). Fungal structures were isolated from diseased leaves and genomic DNA of the pathogen extracted utilizing the method described by Zhu et al. (2019). The internal transcribed spacer (ITS) region was amplified by PCR employing the primers PMITS1/PMITS2 (Cunnington et al. 2003) and the amplicon sequenced by Invitrogen (Shanghai, China). The sequence for the powdery mildew fungus (deposited into GenBank under Accession No. MW144997) showed 100 % identity (558/558 bp) with E. buhrii (Accession No. LC009898) that was reported on Dianthus sp. in Japan (Takamatsu et al. 2015). Pathogenicity tests were done by collecting fungal conidia from infected D. chinensis leaves and brushing them onto leaves of four healthy plants. Four uninoculated plants served as controls. Inoculated and uninoculated plants were placed in separate growth chambers maintained at 19 ℃, 65 % humidity, with a 16 h/8 h light/dark period. Nine-days post-inoculation, powdery mildew disease signs appeared on inoculated plants, whereas control plants remained asymptomatic. The same results were obtained for two repeated pathogenicity experiments. The powdery mildew fungus was identified and confirmed as E. buhrii based on morphological and molecular analysis. An Oidium sp. causing powdery mildew on D. chinensis previously was reported in Xinjiang Province, China (Zheng and Yu 1987). This, to the best of our knowledge, is the first report of powdery mildew caused by E. buhrii on D. chinensis in China (Farr and Rossman 2020). The sudden occurrence of this destructive powdery mildew disease on D. chinensis may adversely affect the health, ornamental value and medicinal uses of the plant in China. Identifying the cause of the disease will support efforts for its future control and management.

Complete nucleotide sequence of a new variant of grapevine fanleaf virus from northeastern China.

The complete RNA1 and RNA2 sequences of a new grapevine fanleaf virus isolate (GFLV-SDHN) from northeastern China were determined. The two RNAs are 7,367 and 3,788 nucleotides (nt) in length, respectively, excluding the poly(A) tails. Compared to other GFLV isolates, GFLV-SDHN has a 22- to 24-nt insertion in the RNA1 5' untranslated region, and there was 19.1-20.1 % and 11.7 %-13.0 % sequence divergence in RNA1, and 15.5 %-20.5 % and 8.5-13.5 % in RNA2, at the nt and amino acid level, respectively. Phylogenetic analysis revealed that the origins of GFLV-SDHN are distinct from those of other GFLV isolates. One recombination event was identified in the 2AHP region of RNA2 in GFLV-SDHN.

Occurrence and genetic diversity analysis of apple stem pitting virus isolated from apples in China.

Two primer pairs were used to detect apple stem pitting virus (ASPV) using a reverse transcription (RT)-PCR test. 82 out of the 141 randomly collected samples, from ten orchards in five provinces and regions of China, tested positive. In the positive samples forty-five (55%) were infected by ASPV and two other viruses. The full coat protein (CP) and the triple gene block (TGB) gene 1, 2 and 3 of partial ASPV isolates were subsequently cloned. The nucleotide and amino acid identities of 39 CP sequence variants from 31 Chinese apple samples were compared with that of previously reported ASPV isolates and were 67.4-96.0% and 68.4-97.7%, respectively. All ASPV sequence variants from Chinese apples separated into two clades with CP- and TGB-based phylogenetic trees, whilst the grouping of TGB2 and TGB3 trees was the same. Three recombinants (FS06-2, X5-2, and XLF-C-2) for CP and six (TH2-5, X8-2, FS05-2, X6-2 and XLF-A-1) recombinants for TGB were identified from the Chinese apple isolates. Two recombinants were found in the TGB sequence of isolate XLF-A-1. The results presented here may assist in the development of a more comprehensive screening tool for apple viruses.

Ectoderm mesenchymal stem cells promote differentiation and maturation of oligodendrocyte precursor cells.

Many neurological diseases are closely associated with demyelination caused by pathological changes of oligodendrocytes. Although intrinsic remyelination occurs after injury, the regeneration efficiency of myelinating oligodendrocytes remains to be improved. Herein, we reported an initiative finding of employing a valuable cell source, namely neural crest-derived ectoderm mesenchymal stem cells (EMSCs), for promoting oligodendrocyte differentiation and maturation by co-culturing oligodendrocyte precursor cells (OPCs) with the EMSCs. The results demonstrated that the OPCs/EMSCs co-culture could remarkably increase the number and length of oligodendrocyte processes in comparison with the mono-cultured OPCs and non-contact OPCs/EMSCs transwell culture. Furthermore, the inhibition experiments revealed that the EMSCs-produced soluble factor Sonic hedgehog, gap junction protein connexin 43 and extracellular matrix molecule laminin accounted for the promoted OPC differentiation since inhibiting the function of anyone of the three proteins led to substantial retraction of processes and detachment of oligodendrocytes. Altogether, OPCs/EMSCs co-culture system could be a paradigmatic approach for promoting differentiation and maturation of oligodendrocytes, and EMSCs will be a promising cell source for the treatment of neurological diseases caused by oligodendrocyte death and demyelination.

Identification of a divergent variant of grapevine berry inner necrosis virus in grapevines showing chlorotic mottling and ring spot symptoms.

A new variant of grapevine berry inner necrosis virus (GINV) was identified by sequencing of small RNA extracted from 'Beta' and Thompson seedless grapevines showing leaf mottle and ring spot symptoms. However, GINV was not found in symptomless samples used as a control. The complete genome sequences of two GINV isolates (KU234316-17) were determined, and these showed 75.76-89.74% sequence identity to the genome of a previously reported Japanese GINV isolate. The new variants appear to be evolutionarily distinct from the original GINV isolate. This is the first report of GINV outside of Japan.

The complete nucleotide sequence and genome organization of pea streak virus (genus Carlavirus).

Pea streak virus (PeSV) is a member of the genus Carlavirus in the family Betaflexiviridae. Here, the first complete genome sequence of PeSV was determined by deep sequencing of a cDNA library constructed from dsRNA extracted from a PeSV-infected sample and Rapid Amplification of cDNA Ends (RACE) PCR. The PeSV genome consists of 8041 nucleotides excluding the poly(A) tail and contains six open reading frames (ORFs). The putative peptide encoded by the PeSV ORF6 has an estimated molecular mass of 6.6 kDa and shows no similarity to any known proteins. This differs from typical carlaviruses, whose ORF6 encodes a 12- to 18-kDa cysteine-rich nucleic-acid-binding protein.

[Effect of Basic Fibroblast Growth Factor and Transforming Growth Factor-Β1 Combined with Bone Marrow Mesenchymal Stem Cells on the Repair of Degenerated Intervertebral Discs in Rat Models].

OBJECTIVE: To evaluate the effects of the combination of basic fibroblast growth factor (bFGF), transforming growth factor-Β1 (TGF-Β1), bone marrow mesenchymal stem cells (BMSCs), and temperature-responsive chitosan hydrogel (TCH) gel on the repair of degenerative intervertebral disc in rat models. METHODS: Rat models of intervertebral disc degeneration were established by acupuncture. The degenerative effects were observed under magnetic resonance imaging (MRI). The BMSCs was cultured in vitro and then transfected by adenovirus with enhanced green fluorescent protein to make it carry the gene of enhanced green fluorescent protein,which functioned as fluorescence labeling. The SD rat models of intervertebral disc degeneration were divided into four groups: group A, treated with the combination of bFGF, TGF-Β1,BMSCs,and TCH gel; group B, treated with the combination of BMSCs and TCH gel;group C, treated with the combination of bFGF,TGF-Β1, and TCH gel;and group D, treated with PBS buffer solution. After the corresponding reagents were injected into the degenerative intervertebral discs of each group, the rats were cultivated for another four weeks and then the repair effects of the intervertebral discs were observed under MRI. Furthermore,the intervertebral discs of each group were taken out and observed by HE and Masson staining. The nucleus pulposus was aspirated and the expressions of aggrecan,collagen 2,Sox-9,and collagen I of nucleus pulposus of each group were tested by reverse transcription polymerase chain reaction and Western blot. RESULTS: The transplanted BMSCs survived in the intervertebral disc and differentiated into nucleus pulposus-like cells. MRI showed that:the signal intensity of the nucleus pulposus of group A was much higher than that of the rest groups, the signal intensity of group B was higher than that of group C, and the signal intensity of group D was the lowest,in which the dura mater spinalis was in compression and the spinal cord changed in beaded shape. The differences of the Pfirrmann grading among the four groups had statistical significance (P<0.05). The results of the HE and Masson stains showed:the intervertebral disc of group A was well-structured,the quantity of nucleus pulposus cells was larger than that of the other three groups,and the boundary between the nucleus pulposus and the annulus fibrosus was clearly defined;the quantity of the nucleus pulposus cells of group B was larger than that of group C, and the broken annulus fibrosus was not observed in group B, while the broken annulus fibrosus could be observed in group C; and, the nucleus pulposus cells of group D were replaced by fibrous tissue. The results of the reverse transcription polymerase chain reaction and Western blot tests showed that,in terms of the expressions of aggrecan,collagen 2 and Sox-9,group A was the highest, followed by group B,group C,and group D (P<0.05); in terms of the expression of collagen 1,there was no obvious difference among these four groups (P>0.05). CONCLUSIONS: The transplanted BMSCs can survive in the degenerative intervertebral disc and differentiate into nucleus pulposus-like cells. The combination of bFGF, TGF-Β1, BMSCs,and TCH gel has obvious repair effect on the degenerative intervertebral discs. The effect of the combination of BMSCs and TCH gel on transplantation therapy of the degenerative intervertebral discs is better than that of the combination of bFGF, TGF-Β1 and TCH gel but worse than that of the combination of bFGF, TGF-Β1, BMSCs, and TCH gel.

PDK4 inhibits osteoarthritis progression by activating the PPAR pathway.

BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease caused by the deterioration of cartilage. However, the underlying mechanisms of OA pathogenesis remain elusive. METHODS: Hub genes were screened by bioinformatics analysis based on the GSE114007 and GSE169077 datasets. The Sprague-Dawley (SD) rat model of OA was constructed by intra-articular injection of a mixture of papain and L-cysteine. Hematoxylin-eosin (HE) staining was used to detect pathological changes in OA rat models. Inflammatory cytokine levels in serum were measured employing the enzyme-linked immunosorbent assay (ELISA). The reverse transcription quantitative PCR (RT-qPCR) was implemented to assess the hub gene expressions in OA rat models. The roles of PDK4 and the mechanism regulating the PPAR pathway were evaluated through western blot, cell counting kit-8 (CCK-8), ELISA, and flow cytometry assays in C28/I2 chondrocytes induced by IL-1ß. RESULTS: Six hub genes were identified, of which COL1A1, POSTN, FAP, and CDH11 expressions were elevated, while PDK4 and ANGPTL4 were reduced in OA. Overexpression of PDK4 inhibited apoptosis, inflammatory cytokine levels (TNF-α, IL-8, and IL-6), and extracellular matrix (ECM) degradation protein expressions (MMP-3, MMP-13, and ADAMTS-4) in IL-1ß-induced chondrocytes. Further investigation revealed that PDK4 promoted the expression of PPAR signaling pathway-related proteins: PPARA, PPARD, and ACSL1. Additionally, GW9662, an inhibitor of the PPAR pathway, significantly counteracted the inhibitory effect of PDK4 overexpression on IL-1ß-induced chondrocytes. CONCLUSION: PDK4 inhibits OA development by activating the PPAR pathway, which provides new insights into the OA management.