An innovative application of follicular unit extraction technique in the treatment of bromhidrosis

BACKGROUND

Surgery is the most effective way to treat bromhidrosis, but postoperative complications are still the biggest obstacles for patients to choose surgical treatment.

OBJECTIVES

To introduce an innovative application of follicular unit extraction (FUE) in the treatment of bromhidrosis.

METHODS

We conducted a case series study on 20 patients who received FUE technique for the treatment of bromhidrosis. The axillary hair follicles were extracted with a one-millimetre punch. The released hair follicles were collected for histological examination. After the operation, the wounds were wrapped with moderate pressure. The dressing was removed 24 h after the FUE operation. The postoperative complications were collected, and the improvement of malodour was evaluated by the 10-point visual analogue scale.

RESULTS

Immediately postoperation, many needle-shaped holes appeared in the armpits. The holes healed 7 days after the operation, with no scar or pinpoint-like scars. Except for a female who complained of mild pain in the left armpit, no other patients had any discomfort. The malodour level varied between 0 and 4 during the follow-up period. The tissue examination showed that more than 90% of the completely plucked hair follicles were accompanied by apocrine glands, and many blocked and dilated apocrine glands were observed. The lumens of the blocked glands were filled with decapitation products, which were positive for K5, Brst-2 and CEA.

CONCLUSIONS

Patients with bromhidrosis have a positive response to FUE technique. The FUE technique is well-tolerated, with only a few postoperative complications, which deserves to be widely promoted.

Watermelon crinkle leaf-associated virus 1 and watermelon crinkle leaf-associated virus 2 have a bipartite genome with molecular signatures typical of the members of the genus Coguvirus (family Phenuiviridae)

Watermelon crinkle leaf-associated virus 1 and watermelon crinkle leaf-associated virus 2 (WCLaV-1 and WCLaV-2), two unclassified members of the order Bunyavirales, are phylogenetically related to members of the genus Coguvirus (family Phenuiviridae). The genome of both viruses was reported previously to be composed of three RNA segments. However, the terminal sequences of two genomic RNA segments, namely those encoding the putative movement protein (MP) and the nucleocapsid (NP) protein, remained undetermined. High-throughput sequencing of total RNA and small RNA preparations, combined with reverse transcription PCR amplification followed by sequencing, revealed that the WCLaV-1 and WCLaV-2 possess a bipartite genome consisting of a negative-sense RNA1, encoding the RNA-dependent RNA polymerase, and an ambisense RNA2, encoding the putative movement (MP) and nucleocapsid (NP) proteins. The two open reading frames of RNA2 are in opposite orientations and are separated by a long AU-rich intergenic region (IR) that may assume a hairpin conformation. RNA1 and RNA2 of both viruses share almost identical 5' and 3' termini, which are complementary to each other up to 20 nt. This genome organization is typical of members of the genus Coguvirus, with which WCLaV-1 and WCLaV-2 also share similar terminal 5' and 3' sequences of RNA1 and RNA2. These molecular features, together with phylogenetic reconstructions support the classification of WCLaV-1 and WCLaV2 as members of two new species in the genus Coguvirus.

Viromics unveils extraordinary genetic diversity of the family Closteroviridae in wild citrus

Our knowledge of citrus viruses is largely skewed toward virus pathology in cultivated orchards. Little is known about the virus diversity in wild citrus species. Here, we used a metatranscriptomics approach to characterize the virus diversity in a wild citrus habitat within the proposed center of the origin of citrus plants. We discovered a total of 44 virus isolates that could be classified into species Citrus tristeza virus and putative species citrus associated ampelovirus 1, citrus associated ampelovirus 2, and citrus virus B within the family Closteroviridae, providing important information to explore the factors facilitating outbreaks of citrus viruses and the evolutionary history of the family Closteroviridae. We found that frequent horizontal gene transfer, gene duplication, and alteration of expression strategy have shaped the genome complexity and diversification of the family Closteroviridae. Recombination frequently occurred among distinct Closteroviridae members, thereby facilitating the evolution of Closteroviridae. Given the potential emergence of similar wild-citrus-originated novel viruses as pathogens, the need for surveillance of their pathogenic and epidemiological characteristics is of utmost priority for global citrus production.

Closterovirids are principal plant pathogens for citrus trees and other plants, as they sometimes cause new or re-emerging diseases. However, the closterovirid diversity in natural plant hosts, especially citrus plants, is unclear. Here, we describe three novel species and Citrus tristeza virus within the family Closteroviridae that were sampled from wild citrus trees growing in their natural habitat in southwestern China. The presence of three different taxon classes of the family Closteroviridae indicates the geographical uniqueness of the sampling region for citrus closterovirid evolution. Our analysis shows that frequent horizontal gene transfer, gene duplication, alteration of expression strategy, and recombination have been important evolutionary processes in the diversification of the family Closteroviridae. Our study also shows the significance of natural reserves as potential sources of disease agents endangering cultivated crop plants.

Spatial Virome Analysis of Zanthoxylum armatum Trees Affected With the Flower Yellowing Disease

Zanthoxylum armatum is an important woody crop with multiple applications in pharmaceutics, cosmetics, and food industries. With continuous increases in the plantation area, integrated pest management is required for scale production when diseases caused by biotic factors such as pests and pathogens have become new problems, one of which is the infectious flower yellowing disease (FYD). Here, isolates of a new illarvirus (3) and a new nepovirus-associated subviral satellite RNA (12) were identified in Z. armatum, in addition to 38 new isolates of four previously reported RNA viruses. Sequence variation can be observed in viral/subviral quasispecies and among predominant isolates from the same or different samples and geographic origins. Intriguingly, RNA sequencing of different diseased trees invariably showed an extraordinary pattern of particularly high reads accumulation of the green Sichuan pepper-nepovirus (GSPNeV) and the satellite RNA in symptomatic tissues. In addition, we also examined small RNAs of the satellite RNA, which show similar patterns to those of coinfecting viruses. This study provides further evidence to support association of the FYD with viral/subviral infections and deepens our understanding of the diversity and molecular characteristics of the viruses and satellite, as well as their interactions with the host.

[Analysis of the time for observation and related factors at clinics after vaccination among children's parents]

Objective: To understand the time for observation and related factors in the clinics after vaccination among children's parents. Methods: From December 2019 to January 2020, parents of children aged 0-3 years were recruited by multiple-stage sampling from 34 vaccination clinics in 12 districts and counties in 6 provinces (Shandong, Guangdong, Henan, Sichuan, Inner Mongolia, and Liaoning). A questionnaire survey on the time of observation after vaccination was conducted. A multivariate logistic regression model was used to analyze the related factors of parental observation time after vaccination. Results: A total of 3 292 parents of 0-3 year's old children were selected, and 3 178 parents were finally included in the analysis. 87.85%(2 792/3 178) of the parents reported that the observation time after vaccination at clinics was ≥30 minutes. Multivariate logistic regression analysis showed that, after adjusting for the regions, the main factors affecting the observation time at clinics after vaccination among parents appeared as observation time informed by physicians at the clinic appeared ≥30 minutes (OR=31.622, 95%CI: 19.847-50.384), parents were medical personnel (OR=2.779, 95%CI: 1.505-5.133), parents being volunteers working on vaccination-related publicity and education activities (OR=1.986, 95%CI: 1.438-2.743), parents aged 35 years old or above (OR=1.900, 95%CI: 1.215-2.971), being parents of the first child (OR=1.663, 95%CI: 1.282-2.156), per capita annual income of the family as 8 000- Yuan (OR=1.646, 95%CI: 1.168-2.319), children aged 0-12 months old (OR=1.646, 95%CI: 1.203-2.252) or 13-24 months old (OR=1.506, 95%CI: 1.064-2.133), obedient to physicians' advice at the clinic (OR=1.481, 95%CI: 1.067-2.055). Conclusions: The proportions of parents observed for ≥30 minutes at the clinics of vaccination were high. When the information was from the physicians at the vaccination clinic, the observation time was the most critical factor for parents to observe at clinics as required.

[Impact of additional time spent for vaccination services on overall satisfaction rate in parents]

Objective: To understand the overall satisfaction rate with vaccination services in parents of children, and the impact of additional time consumed for vaccination service on overall satisfaction rate. Methods: From December 2019 to January 2020, a total of 3 178 parents of 0-3 years old children were investigated to collect the information about their basic characteristics, additional time spent for vaccination service and overall satisfaction through questionnaires. Binary logistic regression model and restricted cubic spline model were used to evaluate the impact of additional time spend on the overall satisfaction rate. Results: The overall satisfaction rate of parents with vaccination services was 92.32%. The median time for parents to move from home to vaccination clinic was 10.00 (10.00, 20.00) minutes, the median waiting time to make an appointment was 10.00 (5.00, 15.00) minutes, the median waiting time for vaccination was 5.00 (3.00, 10.00) minutes, and the median total additional time spent was 30.00 (20.00, 45.00) minutes. The binary logistic regression analysis showed that after adjusting the relevant factors, the main factors affecting the overall satisfaction rate were the waiting time for making an appointment (the 4- minutes group vs. 8- minutes group: OR=1.863, 95%CI: 1.307-2.657), waiting time for vaccination (the <4 minutes group vs. 8- minutes group: OR=1.529, 95%CI: 1.102-2.120; the 4- minutes group vs. 8- minutes group: OR=1.534, 95%CI: 1.104-2.130), total additional time spent (the 15- minutes group vs. 30- minutes group: OR=1.470, 95%CI: 1.094-1.976). Restricted cubic spline analysis showed that the waiting time for making an appointment (non-linear: χ²=13.18, P=0.001), the waiting time for vaccination (non-linear: χ²=13.50, P=0.001), and the total additional time consumed (non-linear: χ²=9.38, P=0.009) showed a non-linear inverted "V" dose response relationship to the overall satisfaction of vaccination services. Conclusions: The waiting time for parents to make an appointment, the waiting time for vaccination and the total additional time spent for receiving vaccination services affected the overall satisfaction rate of the vaccination services. And the waiting time for making an appointment was the most important factor, and it is necessary to shorten the waiting time for appointment. It is suggested that the vaccination clinic should make use of information technology (such as WeChat public account, APP) to make accurate appointments, make appointments to the time period to control the number of people within time period.

Complete genome sequence of a novel citrus virus with characteristics of members of the family Tymoviridae

A novel positive-stranded RNA virus provisionally named "citrus virus C" (CVC) was discovered in citrus trees displaying mottling symptoms. Its genome comprises 7,215 nucleotides (nt), excluding the 3' poly(A) tail, and contains two open reading frames (ORFs) that encode a replication-associated polyprotein (RP) and a putative coat protein (CP). The CVC genome contains a 16-nt 'marafibox', which is highly conserved in most viruses belonging to the genus Marafivirus of the same family. Sequence analysis suggested that the virus is most closely related to grapevine Red Globe virus (GRGV), which is yet to be officially classified in the family Tymoviridae. The sequence identities between CVC and GRGV in the whole genome (50.7%, nt) and CP (49.4% for amino acid, and 53.9% for nt) are lower than the thresholds (80% in the genome and 90% in the CP) for species demarcation in the family. Therefore, it is legitimate to propose that CVC is a member of new species in the family Tymoviridae.

Seed dormancy profiles for forest dynamics plot data: focusing on a tropical seasonal rainforest in Xishuangbanna, southwest China

Long-term forest dynamics monitoring plots provide information on number of individual species in the plot, allowing us for the first time to construct seed dormancy profiles at the species and individual levels for a specific site. Focusing on the Xishuangbanna tropical season rainforest plot (XTRDP), we used data from nine forest dynamics plots (two for tropical, four for subtropical and three for temperate) and information on kind of seed dormancy to generate seed dormancy profiles for communities across tropical to temperate latitudes at the species and individual levels. Seed dormancy information was collected from previous publications, and some data were provided by two germplasm banks that test seed germination of wild plants in China. In XTRDP, 35% of the species and 58% of individuals have non-dormant seeds; the dominant species have non-dormant seeds. In all plots, the most common kind of dormancy among species and individuals with dormant seeds was physiological dormancy. At the species level, the profile for tropical, subtropical and temperate plots was similar to profiles for each of these vegetation regions. In all plots, except one subtropical plot, the percentage of species versus individuals with dormant seeds differed. All temperate plots had a higher percentage of individuals than species with dormant seeds, but this pattern was not consistent for tropical or subtropical plots. We show that dormancy increases with latitude at both the species and individual levels. Dormancy profiles at the individual tree level provide new insight into seed dormancy relationships within plant communities.

Occurrence and Distribution of Actinidia Viruses in Shaanxi Province of China

Kiwifruit (Actinidia spp.) is an economically important fruit crop globally. China is the largest kiwifruit-growing country in the world, and Shaanxi Province is the major kiwifruit-growing region in China. A systematic survey detected various symptoms in kiwifruit plants grown in a commercial kiwifruit field in Shaanxi Province. Samples were collected from kiwifruit plants showing symptoms and used for virus detection by high-throughput sequencing. In addition to 10 known kiwifruit viruses, three new viruses were detected and tentatively named Actinidia yellowing ringspot virus (AYRSpV), Actinidia yellowing virus 1 (AcYV1), and Actinidia yellowing virus 2 (AcYV2). The genome sequences of the three new viruses and four known viruses were determined. Based on the demarcation criteria of the International Committee on Taxonomy of Viruses, AYRSpV might be a new member of the genus Ilarvirus in the family Bromoviridae, AcYV1 might be a new virus of the genus Waikavirus in the family Secoviridae, and AcYV2 might be a novel virus in the family Tombusviridae. Spherical viral particles were found in the samples infected with AYRSpV, AcYV1, and AcYV2 by transmission electron microscopy. Further analysis showed that all 13 viruses can infect both Actinidia deliciosa and A. chinensis but the incidences of these infections vary among different kiwifruit cultivars in different regions. These results provide valuable information for understanding the virome of kiwifruit in China.

Complete nucleotide sequence of a new carlavirus infecting Aconitum carmichaelii in China

A novel virus was identified in aconite (Aconitum carmichaelii Debx.) in China by high-throughput sequencing (HTS) and tentatively named "aconite virus A" (AcVA). The genomic RNA of AcVA consists of 8,844 nucleotides, excluding the poly(A) at the 3' end. Analysis of the genomic organization of AcVA indicated that it possesses a genomic structure that is typical of carlaviruses and contains six putative open reading frames (ORFs). Pairwise analysis revealed that the replicase and coat protein of AcVA share the highest amino acid sequence identity (43.78% and 57.01%) with those of coleus vein necrosis virus (CVNV) and butterbur mosaic virus (ButMV), respectively. Based on the current classification criteria for carlaviruses, AcVA should be considered a distinct member of the genus Carlavirus.

Molecular characterization of a novel cytorhabdovirus associated with chrysanthemum yellow dwarf disease

Deep-sequencing analysis of a chrysanthemum plant with yellow dwarf symptoms led to the discovery of a novel putative cytorhabdovirus, here tentatively named "chrysanthemum yellow dwarf associated virus" (CYDaV). Its negative-sense single-stranded RNA genome comprises 14,086 nucleotides and contains eight open reading frames in the order 3' leader-N-P'-P-P3-M-G-P6-L-5' trailer. CYDaV shares moderate sequence similarity (< 54.2% nucleotide and 51% amino acid sequence identity) with its cytorhabdovirus counterparts in cognate genes. Phylogenetic analysis showed that CYDaV clustered with strong support with alfalfa dwarf virus, raspberry vein chlorosis virus, and strawberry crinkle virus. These findings suggest that CYDaV should be considered a novel member of the genus Cytorhabdovirus, family Rhabdoviridae.

Natural Defect of a Plant Rhabdovirus Glycoprotein Gene: A Case Study of Virus-Plant Coevolution

Seven isolates of a putative cytorhabdovirus (family Rhabdoviridae, order Mononegavirales) designated as citrus-associated rhabdovirus (CiaRV) were identified in citrus, passion fruit, and paper bush from the same geographical area in China. CiaRV, bean-associated cytorhabdovirus (Brazil), and papaya virus E (Ecuador) should be taxonomically classified in the species Papaya cytorhabdovirus. Due to natural mutations, the glycoprotein (G) and P4 genes were impaired in citrus-infecting isolates of CiaRV, resulting in an atypical rhabdovirus genome organization of 3' leader-N-P-P3-M-L-5' trailer. The P3 protein of CiaRV shared a common origin with begomoviral movement proteins (family Geminiviridae). Secondary structure analysis and trans-complementation of movement-deficient tomato mosaic virus and potato virus X mutants by CiaRV P3 supported its function in viral cell-to-cell trafficking. The wide geographical dispersal of CiaRV and related viruses suggests an efficient transmission mechanism, as well as an underlying risk to global agriculture. Both the natural phenomenon and experimental analyses demonstrated presence of the "degraded" type of CiaRV in citrus, in parallel to "undegraded" types in other host plant species. This case study shows a plant virus losing the function of an important but nonessential gene, likely due to host shift and adaption, which deepened our understanding of course of natural viral diversification.

Discovery and Characterization of a Novel Ampelovirus on Firespike

A novel RNA virus was identified in firespike (Odontonema tubaeforme) plants exhibiting leaf curling and chlorosis. The molecular features of the viral genomic RNA and proteins resemble those of ampeloviruses. Based on sequence comparisons and phylogenetic analysis, we propose a new species in the genus Ampelovirus, which we have tentatively named Firespike leafroll-associated virus (FLRaV). Bioassays showed that the virus is mechanically transmissible to Nicotiana benthamiana. In addition, a full-length cDNA clone of FLRaV could successfully infect N. benthamiana via agroinfiltration.

2020 taxonomic update for phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

[Using structured decision-making to identify the appropriate type of entity for the centers for disease control and prevention of China]

Objective: To develop evidence-based appropriate type of entity for the Centers for Disease Control and Prevention in order to improve the performance of disease control and prevention system in China. Methods: This study firstly proposed the core functions and essential public health programs for the Centers for Disease Control and Prevention. Using Structured Decision-Making, this study presented three alternative options for type of entity to make essential public health programs succeed, and reviewed the pros and cons of alternative options based on 15 evaluation indicators. Questionnaires were distributed to 47 stakeholders between April 10 and April 20 of 2020. Finally, an appropriate type of entity for the Centers for Disease Control and Prevention was identified by using both qualitative and quantitative methods. Results: A total of 47 stakeholders ranked alternative options. Aggregated scores of each alternative option was computed after weighting each indicators. The results shows that Option 1(professional technical civil service organization)has the highest score (58.22). Conclusion: Professional technical civil service organization is appropriate type of entity for Centers for Disease Control and Prevention.

Identification and Characterization of Two Novel Geminiviruses Associated with Paper Mulberry (Broussonetia papyrifera) Leaf Curl Disease

Paper mulberry (Broussonetia papyrifera) is a perennial woody plant used as source material for Cai Lun paper making, in traditional Chinese medicine, and as livestock feed. To identify the presence of viruses in paper mulberry plants affected by a disease with leaf curl symptoms, high-throughput sequencing of total RNA was performed. Analysis of transcriptome libraries allowed the reconstruction of two geminivirus-like genomes. Rolling-circle amplification and PCR with back-to-back primers confirmed the presence of two geminiviruses with monopartite genomes in these plants, with the names paper mulberry leaf curl virus 1 and 2 (PMLCV-1 and PMLCV-2) proposed. The genomes of PMLCV-1 (3,056 nt) and PMLCV-2 (3,757 to 3,763 nt) encode six proteins, with the V4 protein of PMLCV-1 and the V3 proteins of both viruses having low similarities to any known protein in databases. Alternative splicing of an intron, akin to that of mastre-, becurto-, capula-, and grabloviruses, was identified by small RNA (sRNA)-seq and RNA-seq reads mapping to PMLCV-1 and PMLCV-2 antisense transcripts. Phylogenetic analyses and pairwise comparisons showed that PMLCV-1 and PMLCV-2 are most closely related to, but distinct from, two unassigned geminiviruses, citrus chlorotic dwarf associated virus and mulberry mosaic dwarf associated virus, suggesting that they are two new members of the family Geminiviridae. Field investigation confirmed the close association of the two viruses with leaf curl symptoms in paper mulberry plants and that coinfection can aggravate the symptoms.

A challenging case of hypercapnic respiratory failure during pregnancy

We describe a 40-year-old female who presented with progressive breathlessness and hypercapnic respiratory failure during pregnancy secondary to undiagnosed muscle-specific kinase myasthenia gravis. Her presentation was progressive and protracted, having over five contacts with healthcare professionals over nine months, many of these predating her pregnancy. Her atypical presentation for myasthenia with minimal limb weakness led to consideration of other causes of hypercapnic respiratory failure. Once diagnosed, she was treated with intravenous immunoglobulin and non-invasive ventilation. She gave birth to a pre-term infant by planned caesarean section. Her insidious presentation and the progressive nature of her breathlessness were unusual and our report highlights the predominant involvement of respiratory muscles in muscle-specific kinase myasthenia. Her pregnancy may have further delayed her diagnosis due the attribution of some symptoms to normal pregnancy. Early recognition and treatment of myasthenia gravis are important to prevent life-threatening complications.

Mulberry (Morus alba) is a new natural host of Citrus leaf blotch virus in China

Mulberries (Morus spp., family Moraceae) are economically important deciduous woody plants. Their leaves are food for silkworms, and both the fruits and leaves have nutritional and medicinal values (Qin et al. 2012). The plants are widely distributed globally and have been cultivated in China for more than 5,000 years (Xie et al. 2014). In April 2019, virus-like symptoms of chlorotic leaf spots and, occasionally witches' broom were observed in trees of white mulberry (M. alba) in Shapingba district of Chongqing province. To investigate if any potential viral agent is associated with the symptoms, total RNA was extracted from leaves of one symptomatic tree using an RNAprep Pure Plant Plus Kit (TianGen, China). Ribosomal RNAs were depleted using a TruSeq RNA Sample Prep Kit (Illumina, USA), and the depleted RNA was used for construction of a cDNA library for sequencing using an Illumina HiSeq X-ten platform with pair-ended reads length layout 150 bp. Adaptors, low-quality reads and mulberry genomes-derived reads (He et al. 2013) were removed from a total of 25,433,798 reads using the CLC Genomics Workbench 11 (Qiagen, USA) and the clean reads of 936,562 were subjected to de novo assembly that generated 4,278 contigs (200-3,862 bp). These sequences were annotated by Blastx searches to local Viruses_NR and viroid datasets downloaded from GenBank. Finally, except three contigs (3,862 nt, 1,950 nt, and 1,179 nt) with 81.4-90% nucleotide sequence identities to citrus leaf blotch virus (CLBV, genus Citrivirus, family Betaflexiviridae), no other contigs were identified as viral-related. Total clean reads of 113,185 were mapped to the viral contigs with average coverage depth of 1,915, suggesting the presence of CLBV in the symptomatic tree. To recover the complete genome of CLBV, overlapping fragments were amplified by RT-PCR using virus-specific primer pairs. The 5' and 3' termini were determined by rapid amplification of cDNA ends (RACE kit, Invitrogen, USA). Five clones per amplicon were sequenced in two directions (Cao et al. 2018). The complete genome of the mulberry strain of CLBV (CLBV-ML, GenBank accession no. MT767171) is 8,776 nucleotides (nt) in length, excluding the poly (A) tail. CLBV-ML is similar to extant CLBV isolates in genome structure. BLASTn analysis showed that CLBV-ML had highest nucleotide sequence identities of 79.65-81.56% with Actinidia isolates (Liu et al. 2019) of CLBV at the whole genome. Phylogenetic analysis also placed it with the Actinidia isolates, indicating they are closely related. Thus, CLBV-ML is a highly divergent strain of CLBV. To study the occurrence of CLBV-ML, a total of 62 mulberry samples (42 with similar symptoms and 20 without symptoms) were randomly collected from Shapingba and tested by conventional RT-PCR using an isolate-specific primer pair (CLBV-F7182: ACCAATGACAATGCCACA; CLBV-R7857: TTATGAAACTCTTCCCACTT) designed in the CP gene to amplify a 676 bp fragment. The virus was detected in 37 symptomatic trees (88%) and 2 (10%) asymptomatic trees, suggesting the association of CLBV-ML with the symptoms. To the best of our knowledge, this is the first report of CLBV infection in mulberry which expands the host range of CBLV.

RNA-Seq Reveals Hawthorn Tree as a New Natural Host for Apple Necrotic Mosaic Virus, Possibly Associated with Hawthorn Mosaic Disease

Apple mosaic disease is widespread in the major apple-producing areas in China and is frequently associated with the presence of the newly identified Apple necrotic mosaic virus (ApNMV), belonging to subgroup 3 of Ilarvirus genus in the family of Bromoviridae. Mosaic symptoms were also observed in a hawthorn tree. Deep sequencing revealed the hawthorn tree with mosaic symptom was infected by ApNMV, which was confirmed by RT-PCR. The complete nucleotide sequences of RNA1 (3,378 nt), RNA2 (2,778 nt), and RNA3 (1,917 nt) of ApNMV from the hawthorn were obtained, sharing 93.8 to 96.8%, 89.7 to 96.1%, and 89.8 to 94.6% nucleotide identities with those from apples and crabapples, respectively. Two hypervariable regions were found, which showed 59.2 to 85.7% and 64.0 to 89.3% sequence identities at position 142 to 198 aa and at position 780 to 864 aa in the POL protein, respectively, between the hawthorn isolate and other isolates (apple, crabapple). A grafting test demonstrated that ApNMV was easily transmissible from hawthorns to apple trees, with severe chlorosis, yellowing, mosaic, curling, and necrosis. In addition, a total of 11,685 hawthorn trees were surveyed for the incidence of mosaic disease from five provinces in China, and only six were found showing typical mosaic symptoms. A total of 145 individual trees (six symptomatic, 68 asymptomatic, and 71 other symptoms) were tested for the presence or absence of ApNMV by RT-PCR. Among them, six symptomatic, four asymptomatic, and 10 other symptomatic trees tested positive for ApNMV. Taken together, these results demonstrated that the hawthorn tree was identified as a new natural host for ApNMV with a relatively low frequency (13.8%, 20 out of 145) in the main producing areas, and it was likely to be the causal pathogen of hawthorn mosaic disease.

First report of tomato spotted wilt virus (TSWV) isolated from nasturtium (Tropaeolum majus L.) with a serious leaf mosaic disease in China

Tomato spotted wilt virus (TSWV, Genus Orthotospovirus, Family Tospoviridae) is a thrips-transmitted negative-stranded RNA virus with a large host range. Major economic losses caused by TSWV have been recorded in various crops such as tomato, pepper and lettuce (Pappu et al., 2009; Adams et al., 2017). Nasturtium (Tropaeolum majus L.), a common flowering plant species native to Peru, is generally cultivated as a garden and greenhouse ornamental plant in China. It is also known for its medical, edible and cosmetic values (Jakubczyk et al., 2018). In June 2019, a serious leaf mosaic disease (Figure S1) was observed in ~77% of T. majus plants in Beiling Park in Shenyang City, Liaoning, China. To reveal the possible viral agent associated with the disease, leaf tissue was collected from 9 symptomatic and 2 asymptomatic plants, followed by total RNA extraction from each of the samples using RNASimple Total RNA Kit (Tiangen, Beijing, China). The RNA from one representative symptomatic sample (Figure S1, d) was used to construct an rRNA-depleted library using the Ribo-Zero™ rRNA Removal Kit (Plant Leaf) (Illumina, CA, USA). The library was subjected to RNA-Seq using a BGISEQ platform (Shenzhen Huada Gene Science and Technology Service Co., Ltd., Shenzhen, China). A total of 109,279,540 quality-filtered reads were obtained using the CLC Genomics Workbench 9.5 software (Qiagen, Valencia, CA, USA). Clean reads were assembled into 88,091 contigs ranging in length from 200 to 19,695 bp using Velvet (Zerbino and Birney 2008). Among the contigs, three sized at 8801, 4617 and 2909 bp were found to share a sequence identity of 98.74-99.35% with the RNA segments (L, M and S) of TSWV. No sequences of other viruses, viroids included, were detected. Ten primer pairs were designed based on the TSWV contigs to obtain the full genome sequence of the virus (Table S1). Five, three, and two amplicons were obtained for the TSWV RNA segments L, M and S, respectively, from the same RNA sample used in the RNA-Seq process. These amplicons were then cloned into the pMD18T vector (TaKaRa, Dalian, China) and Sanger sequenced. The resulting sequences were assembled and analyzed using the DNAMAN version 8.0 (LynnonBiosoft, Quebec, Canada) and DNAStar version 6.0 software (DNAStar Inc, Madison, WI, USA) (Table S1). The RNA segments were determined to be 8,914 nt (L, accession no. MT241883), 4,791 nt (M, MT241884) and 2,922 nt (S, MT241885) in length. They shared a sequence identity of >99% with the "LL-N.05" (segment L, KP008128) and "SPAIN-1" (segment S, AY744479) isolates from tomatoes in Spain and the "Beijing" isolate (segment M, MH717046) from chrysanthemum in China. These results, together with phylogenetic analysis, suggest that the isolate (designated as isolate LN-HJL) was likely resulted from genome reassortment between other isolates. No reliable recombination events were detected in the RNA segments of LN-HJL by the RDP4 program (Martin et al., 2015). RT-PCR assay with primer pair S-1F/1R on all samples led to positive detection of TSWV only in the symptomatic samples (Figure S1, g), indicating that the virus was likely responsible for the disease symptoms observed in T. majus. To the best of our knowledge, this is the first report of the TSWV infection in T. majus in China, and the second in the world since the first report in the USA (Ie, 1964). TSWV-infected T. majus plants not only lose their aesthetic and economic values (Figure S1, f), but also may act as reservoirs for the spread of TSWV to other important crops. T. majus should therefore be monitored regularly for the virus and managed accordingly in China.

Complete genome sequence of citrus yellow spot virus, a newly discovered member of the family Betaflexiviridae

A novel plant virus with a positive single-stranded (+ss) RNA genome was detected in Taibei pomelo (Citrus grandis (L.) Osbeck cv. Taibeiyou) in China by high-throughput sequencing (HTS). Tentatively named "citrus yellow spot virus" (CiYSV), it has 8,061 nucleotides (nt) excluding the poly(A) tail and contains three open reading frames (ORFs). ORF1 is predicted to encode a replicase polyprotein (RP) with conserved domains typical of members of the family Betaflexiviridae. ORF2 encodes a protein sharing the highest sequence identity with the putative movement protein (MP) found in the negative-stranded RNA virus Trifolium pratense virus B (TpVB, MH982249, genus Cytorhabdovirus). ORF3 overlaps ORF2 by 137 nt and encodes a predicted coat protein (CP) that is distantly related to those of betaflexiviruses. Phylogenetic analysis based on the MP amino acid sequence showed that the CiYSV clustered with cytorhabdoviruses rather than betaflexiviruses, whilst trees based on the whole genome, RP, and CP showed it to belong to the family Betaflexiviridae but to be distinct from any other known betaflexiviruses. These results suggest that the CiYSV should be considered the first member of a tentative new genus in the family Betaflexiviridae.