A model of hybrid speciation process drawn from three new poplar species originating from distant hybridization between sections.

Although numerous studies have been conducted on hybrid speciation, our understanding of this process remains limited. Through an 18-year systematic investigation of all taxa of Populus on the Qinghai-Tibet Plateau, we discovered three new taxa with clear characteristics of sect. Leucoides. Further evidence was gathered from morphology, whole-genome bioinformatics, biogeography, and breeding to demonstrate synthetically that they all originated from distant hybridization between sect. Leucoides and sect. Tacamahaca. P. gonggaensis originated from the hybridization of P. lasiocarpa with P. cathayana, P. butuoensis from the hybridization of P. wilsonii with P. szechuanica, and P. dafengensis from the hybridization of P. lasiocarpa with P. szechuanica. Due to heterosis, the three hybrid taxa possess greater ecological adaptability than their ancestral species. We propose a hybrid speciation process model that incorporates orthogonal, reverse, and backcrossing events. This model can adequately explain some crucial evolutionary concerns, such as the nuclear-cytoplasmic conflict on phylogeny and the extinction of ancestral species within the distribution range of hybrid species.

A new species of Populus and the extensive hybrid speciation arising from it on the Qinghai-Tibet Plateau.

While the diversity of species formation is broadly acknowledged, significant debate exists regarding the universal nature of hybrid species formation. Through an 18-year comprehensive study of all Populus species on the Qinghai-Tibet Plateau, 23 previously recorded species and 8 new species were identified. Based on morphological characteristics, these can be classified into three groups: species in section Leucoides, species with large leaves, and species with small leaves in section Tacamahaca. By conducting whole-genome re-sequencing of 150 genotypes from these 31 species, 2.28 million single nucleotide polymorphisms (SNPs) were identified. Phylogenetic analysis utilizing these SNPs not only revealed a highly intricate evolutionary network within the large-leaf species of section Tacamahaca but also confirmed that a new species, P. curviserrata, naturally hybridized with P. cathayana, P. szechuanica, and P. ciliata, resulting in 11 hybrid species. These findings indicate the widespread occurrence of hybrid species formation within this genus, with hybridization serving as a key evolutionary mechanism for Populus on the plateau. A novel hypothesis, "Hybrid Species Exterminating Their Ancestral Species (HSEAS)," is introduced to explain the mechanisms of hybrid species formation at three different scales: the entire plateau, the southeastern mountain region, and individual river valleys.

Polymyositis is a rare and favourable outcome subtype of idiopathic inflammatory myopathy in Chinese patients.

OBJECTIVES: To investigate the prevalence and characteristics of typical polymyositis (PM) in Chinese patients with idiopathic inflammatory myopathy (IIM). METHODS: Patients diagnosed with IIM according to the 2017 EULAR/ACR criteria were included. Serological aspects including myositis-specific antibodies (MSA) and pathological data were re-evaluated. The diagnosis of typical PM was strictly done using the pathological criteria, while excluding other IIM subtypes such as dermatomyositis (DM), immune-mediated necrotising myopathies (IMNM), anti-synthetase syndrome (ASS), and sporadic inclusion body myositis (sIBM), based on their respective diagnostic criteria. RESULTS: A total of 544 IIM patients with muscle biopsy were involved, and 129 of them were diagnosed with initial PM according to the 2017 EULAR/ACR criteria. Only 6 (1.1%, 6/544) patients met the strict definition of typical PM after re-evaluation. Patients with typical PM were MSA-negative (100% vs. 35.7%, p=0.003) and had CD8+ T cells surrounding or invading non-necrotic muscle fibres in muscle biopsies (100% vs. 7.8%, p<0.001) compared to the initially diagnosed PM patients. All typical PM patients achieved clinical remission at the second-year follow-up. Typical PM patients had a favourable prognosis compared to MSA-negative IMNM and unspecific myositis patients. CONCLUSIONS: Strictly defined typical PM is a rare clinical subtype in Chinese IIM patients. Typical PM patients with classical pathology were MSA-negative and responded well to treatment and had a favourable prognosis. It is crucial for clinicians to combine clinical, serological, and pathological features to properly distinguish PM from other IIM subtypes.

Interspecific variations in growth, physiology and Cd accumulation between Populus deltoides and P. × canadensis in response to Cd pollution under two soil types.

Both acid and alkaline purple soils in China are increasingly affected by Cd contamination. The selection of fast-growing trees suitable for remediating different soil types is urgent, yet there is a severe lack of relevant knowledge. In this study, we conducted a controlled pot experiment to compare the growth, physiology, and Cd accumulation efficiency of two widely recognized poplar species, namely Populus deltoides and P. × canadensis, under Cd contamination (1 mg kg-1) in acid and alkaline purple soils. The objective was to determine which poplar species is best suited for remediating different soil types. Our findings are as follows: (1) the total biomass of both poplars remained largely unaffected by Cd pollution in both soil types. Notably, under Cd pollution, the total biomass of P. deltoides in acid purple soil was 1.53 times greater than that in alkaline purple soil. (2) Cd pollution did not significantly induce oxidative damage in the leaves of either poplar species in both soil types. However, in acid purple soil, Cd contamination led to a 21% increase in NO3- concentration and a 44% increase in NH4+ concentration in P. × canadensis leaves, whereas in alkaline purple soil, it led to a 59% increase in NH4+ concentration in P. deltoides leaves. (3) Cd concentrations in all root orders of P. × canadensis were significantly higher than those in P. deltoides, especially in the first three root orders, under alkaline purple soil. The total Cd accumulation by P. × canadensis in Cd-polluted alkaline purple soil was 2.18 times higher than that in Cd-polluted acid purple soil, a difference not observed in P. deltoides. (4) redundancy analysis indicated that the sequestration effect of higher soil organic matter on Cd availability in acid purple soil was more pronounced than the release effects caused by lower pH. In conclusion, P. × canadensis is better suited for remediating alkaline purple soil due to its higher capacity for Cd uptake, while P. deltoides is more suitable for remediating Cd-contaminated acid purple soil due to its better growth conditions and greater Cd enrichment capability.

High prevalence and mortality of Pneumocystis jirovecii pneumonia in anti-MDA5 antibody-positive dermatomyositis.

OBJECTIVES: To identify potential risk factors and prognostic factors of Pneumocystis jirovecii pneumonia (PJP) infection in anti-melanoma differentiation-associated gene 5 antibody-positive DM (anti-MDA5+ DM) patients, and to evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS). METHODS: Anti-MDA5+ DM patients who underwent mNGS or real-time PCR for PJP detection were recruited. The potential risk factors for PJP occurrence and death were analysed via Logistic regression and Cox proportional hazards regression, respectively. The diagnostic efficacy of mNGS was compared with the conventional methods. RESULTS: 91 patients were enrolled and 44 were assigned to PJP+ group. The PJP detection rate was 48.4%. PJP often occurred in the first 3 months (68.2%) of the disease; this period also showed the highest mortality rate (20.5%). Fever and increased lactate dehydrogenase (LDH) were independent risk factors for PJP occurrence, while trimethoprim-sulfamethoxazole (TMP/SMZ) prophylaxis was an independent protective factor (all P < 0.05). Older age and increased LDH were predictors for mortality in patients with anti-MDA5+ DM and PJP (all P < 0.05). In addition, we found that mNGS had a sensitivity of 100.0% and specificity of 90.0% in diagnosing PJP, with the highest area under the curve of 0.95 (P < 0.001). CONCLUSION: PJP has high prevalence and mortality in anti-MDA5+ DM. It is crucial for clinicians to identify high-risk patients and promptly institute TMP/SMZ to prevent PJP. mNGS is the preferred approach for pathogen detection in anti-MDA5+ DM when PJP is suspected.

Comparative Metabolomics and Transcriptome Analysis Reveal the Fragrance-Related Metabolite Formation in Phoebe zhennan Wood.

Nanmu (Phoebe zhennan) has a unique fragrance and is a high-quality tree species for forest conservation. The types and contents of volatile compounds in different tissues of nanmu wood are different, and the study of its volatile metabolites can help us to understand the source of its fragrance and functions. In order to explore the metabolites related to the wood fragrance of nanmu and to find out the unique volatile substances in the heartwood, gas chromatography-mass spectrometry (GC-MS) was performed to analyze the non-targeted metabolomics in five radial tissues from the sapwood to the heartwood of nanmu. A total of 53 volatile metabolites belonging to 11 classes were detected in all tissues, including terpenes, aromatic hydrocarbons, organoheterocyclics, phenols, esters, organic acids, alcohols, alkaloids, alkane, indoles derivatives, and others. And most of the volatile metabolites were identified for the first time in nanmu wood. Among them, terpenes and aromatic hydrocarbons were the main volatile components. In addition, 22 differential metabolites were screened from HW and SW, HW, and TZ via metabolomic analysis. Among these DAMs, three volatile metabolites (cadinene, a sesquiterpenoid; p-cymene, a monoterpenoid; 1,3,5-triisopropylbenzene, an aromatic hydrocarbon) contributed heavily to the characteristic fragrance of the heartwood. Additionally, the expression of transcripts showed that the unigenes in the terpenoid biosynthesis pathway were especially up-regulated in the SW. Therefore, we speculated that fragrance-related metabolites were synthesized in SW and then deposited in heartwood during sapwood transformed to heartwood. The expression levels of transcription factors (e.g., WRKY, C2H2, NAC) acted as the major regulatory factors in the synthesis of terpenoid. The results lay the foundations for further studies on the formation mechanism of fragrance components in nanmu wood and also provide a reference for the further development and utilization of nanmu wood.

Cu(OTf)2/NBS-Mediated Tandem Reaction of 1-Cinnamyl Alcohol-o-Carboranes via Ring Opening of Oxetane with Arenes: An Alternative Approach for the Synthesis of C-Alkenyl-o-Carboranes.

The Cu(OTf)2/NBS-mediated tandem reaction of 1-cinnamyl alcohol-o-carboranes for the synthesis of C-alkenyl-o-carboranes has been developed. Mechanism studies demonstrated that the Cu(OTf)2-promoted ring opening of oxetane with electron-rich arenes as soft nucleophiles was involved and was the key step for the transformation. This work provided an alternative strategy for the synthesis of C-alkenyl-o-carboranes, which has an important reference for the synthesis of o-carborane derivatives with diversity.

Interstitial lung disease is not rare in immune-mediated necrotizing myopathy with anti-signal recognition particle antibodies.

OBJECTIVES: The purpose was to clarify the characteristics of interstitial lung disease (ILD) in immune-mediated necrotizing myopathy (IMNM) patients with anti-signal recognition particle (SRP) antibodies. METHODS: Medical records of IMNM patients with anti-SRP antibodies were reviewed retrospectively. RESULTS: A total of 60 patients were identified. Twenty-seven (45.0%) patients were diagnosed with ILD based on lung imaging: nonspecific interstitial pneumonia (NSIP) in 17 patients (63.0%) and organizing pneumonia in 9 patients (33.3%). Reticulation pattern was identified in 17 patients (63.0%) whereas 10 cases (37.0%) showed ground glass opacity and patchy shadows by high-resolution computed tomography (HRCT). Pulmonary function tests (PFTs) were available in 18 patients, 6 (33.3%) and 10 (55.6%) patients were included in the mild and moderate group, respectively. The average age at the time of ILD onset was significantly older than those without ILD (48.6 ± 14.4 years vs. 41.2 ± 15.4 years, p < 0.05), and the frequency of dysphagia in the ILD group was higher than the group without ILD (p < 0.05). Long-term follow-up was available on 9 patients. PFTs were stable in 8 (88.9%), and the HRCT remained stable in 6 (66.7%) patients. CONCLUSIONS: ILD is not rare in IMNM patients with anti-SRP antibodies, most being characterized as mild to moderate in severity. NSIP is the principal radiologic pattern, and ILD typically remains stable following treatment.

Branch blight of Juglans regia caused by Palmiascoma qujingense in China.

Juglans regia L. is one of the major cultivated walnut species in China for nuts and wood (Pollegioni et al. 2012). In June 2020, branches with blight symptoms were observed in an orchard at Chongzhou City (30°33'34″N, 103°38'35″E). In an orchard of 30 hectares, disease incidence was around 50%. A total of 15 plants were sampled and 40% of their branches were affected by this disease. Firstly, brown and irregular spots appeared, then the spots gradually expanded and encircled the branch, which eventually killed the branch. Five samples of diseased branches from different trees were collected and a single fungal isolate was obtained from each of the five samples using the single ascospore isolation (Chomnunti et al. 2014). Colonies of the five isolates on potato dextrose agar (PDA) were identical that initially appeared white on the top, becoming light to dark brown with age. On the host, ascostroma were black, globose to subglobose, short-papillate, ostiolate, 260 - 410 × 210 - 320 µm (x = 335 × 265 µm, n = 20). Asci were 8-spored, bitunicate, cylindrical, short pedicellate, 55 - 78 × 8 - 12 µm (x = 67.5 × 10 µm, n = 40). Ascospores were 1-septate, fusiform to ellipsoidal, slightly curved, guttulate, 12 - 17 × 3 - 5 µm (x = 14.5 × 4 µm, n = 40). These sexual morphological characteristics are consistent with the Palmiascoma qujingense Phook. & K.D. Hyde (Monkai et al. 2021). Asexual morphs were formed on PDA in incubator after 17 days (25℃, 90% relative humidity, 12-h photoperiod). Conidiomata were black, globose to subglobose, 220 - 300 × 240 - 380 µm (x = 270 × 310 µm, n = 20). Conidia were oblong to ellipsoidal, aseptate and smooth-walled, 3 - 7 × 2 - 4 µm (x = 4.9 × 3 µm, n = 50). The genomic DNA of a representative isolate SICAUCC 21-0013 was extracted, and the internal transcribed spacers (ITS) region, large subunit rDNA (LSU) region, small subunit rDNA (SSU) region, and the largest subunit of RNA polymerase II (rpb2) gene were amplified and sequenced with primers ITS5/ITS4 (White et al. 1990), LR0R/LR5 (Rehner et al. 1994), NS1/NS4 (White et al. 1990), and fRPB2-5F/fRPB2-7cR (Liu et al. 1999), respectively. The sequences were deposited in NCBI with accession numbers MZ983549, MZ959419, MZ951112, and MZ818772, respectively, which showed 100%, 100%, 99.14%, and 99.59% identities with P. qujingense KUMCC 19-0201 (holotype) (accession numbers MT477185, MT477186, MT477183, MT495782respectively). Phylogenetic analysis (maximum likelihood) based on a concatenated dataset showed 93% bootstrap support values with P. qujingense. To verify Koch's postulates, 9 healthy branches from three 1-year-old seedlings were inoculated with conidial suspension (106 conidia/ml) from 4-week-old cultures via pin-prick inoculation (Desai et al. 2019), and the same number of seedlings and branches were inoculated with sterile water as controls. Plants were placed in a greenhouse at 25℃ and 90% RH on a 12-h fluorescent light/dark regime. After 28 days, brown spots were formed on P. qujingense-inoculated branches and similar to those observed in the field, while the controls remained asymptomatic. The pathogen was re-isolated from the lesions and identified by morphology and phylogeny. To our knowledge, this is the first report of P. qujingense causing branch blight on J. regia in the world. This disease potentially impacts the growth and yield of J. regia, and control measures should be made.

Branch blight of Juglans sigillata caused by Juglanconis appendiculata in China.

Juglans sigillata Dode, an endemic walnut species native in southwest China, is mainly used as nuts in Sichuan Province (Jin et al., 2019). In May 2021, symptoms of branches blight were observed in an orchard measuring 10 hectares located in Mianyang City, Sichuan Province (31°5' 25″N, 105°27'36″E, 365 m above sea level). About 40% of plants were diseased in the quadrat consisting of twenty walnut trees, and 20% of branches were dead on each affected tree. Initially, light brown spots appeared; then, the spots expanded to surround the whole branches; finally, the branches changed from brown to reddish-brown and died. Four symptomatic branches were sampled randomly from different trees. Next, four fungal isolates were obtained from the acervuli of each branch using the single-conidium isolation (Chomnunti et al. 2014) and cultured on potato dextrose agar (PDA). The Petri dishes were placed in an incubator and cultured at 25 °C under a 12-h photoperiod. Colonies were initially white with thin aerial mycelia and gradually turned dark grey with irregular margins. Conidiomata were acervular, black and scattered, with a diameter of 0.3 - 0.7 mm. Conidiophores were narrowly cylindrical, simple or branched at the base, 30 - 43 × 3 - 8 µm (x = 36.5 × 5.5 µm, n = 40). Conidiogenous cells were annellidic with distinct annellations. Conidia were unicellular, brown when mature, narrowly ellipsoid with gelatinous sheaths and truncate scars at the base, 17 - 32 × 7 - 12 µm (x = 27 × 9 µm, n = 40). The genomic DNA of a representative isolate SICAUCC 22-0064 was extracted, and the internal transcribed spacer (ITS) region, guanine nucleotide-binding protein subunit beta gene (ms204), translation elongation factor 1-alpha (tef1-α), and partial sequences of ß-tubulin (tub2) were amplified by polymerase chain reaction and sequenced with primers V9G/LR5 (de Hoog & van den Ende 1998), MS-E1F1/MS-E5R1 (Walker et al. 2012), EF1-728F (Carbone & Kohn 1999)/TEF1LLErev (Jaklitsch et al. 2005), and T1/BtHV2r (Voglmayr et al. 2017), respectively. The sequences of ITS, ms204, tef1-α, and tub2 were deposited in NCBI with accession numbers ON000068, ON112376, ON112374, and ON112375, respectively. With the consideration of the sequence lack of ms204 and tub2 in the ex-type strain (D96) of Juglanconis appendiculata Voglmayr & Jaklitsch, the isolate D140 was used for nucleotide blast. The results showed 99.68%, 100%, 100%, and 100% identities of ITS, ms204, tef1-α, and tub2 with D140 (accession numbers KY427138, KY427157, KY427207, KY427226). Phylogenetic analysis based on a combined dataset showed 100% bootstrap with J. appendiculata, and the morphology was consistent with the asexual stage of J. appendiculata (Voglmayr et al., 2017). To verify Koch's postulates, five branches wounded by pin-prick were sprayed with conidial suspension (1 × 105 conidia/mL) in each plant, and three repetitions were performed on healthy 2-year-old potted plants. The same number of branches were sprayed with sterile distilled water as controls. The plants were placed in a greenhouse at 25 ℃ under 90% relative humidity and a 12-h fluorescent light/dark regime. After five weeks, all the inoculated branches showed brown necrosis similar to that observed in the field, and no symptoms occurred on the controls. The pathogens were re-isolated from the necrotic lesions and identified by morphology and phylogeny. J. appendiculata has been reported on Juglans nigra and J. regia in Austria, France, Spain and Greece (Farr & Rossman 2022). This paper is the first report of branch blight on Juglans sigillata caused by J. appendiculata in China. This result may develop the understanding of walnut diseases and lay a foundation for further management.

UVB-Pretreatment-Enhanced Cadmium Absorption and Enrichment in Poplar Plants.

The phenomenon of cross adaptation refers to the ability of plants to improve their resistance to other stress after experiencing one type of stress. However, there are limited reports on how ultraviolet radiation B (UVB) pretreatment affects the enrichment, transport, and tolerance of cadmium (Cd) in plants. Since an appropriate UVB pretreatment has been reported to change plant tolerance to stress, we hypothesized that this application could alter plant uptake and tolerance to heavy metals. In this study, a woody plant species, 84K poplar (Populus alba × Populus glandulosa), was pretreated with UVB and then subjected to Cd treatment. The RT-qPCR results indicated that the UVB-treated plants could affect the expression of Cd uptake, transport, and detoxification-related genes in plants, and that the UVB-Pretreatment induced the ability of Cd absorption in plants, which significantly enriched Cd accumulation in several plant organs, especially in the leaves and roots. The above results showed that the UVB-Pretreatment further increased the toxicity of Cd to plants in UVB-Cd group, which was shown as increased leaf malonaldehyde (MDA) and hydrogen peroxide (H2O2) content, as well as downregulated activities of antioxidant enzymes such as Superoxide Dismutase (SOD), Catalase (CAT), and Ascorbate peroxidase (APX). Therefore, poplar plants in the UVB-Cd group presented a decreased photosynthesis and leaf chlorosis. In summary, the UVB treatment improved the Cd accumulation ability of poplar plants, which could provide some guidance for the potential application of forest trees in the phytoremediation of heavy metals in the future.

Integrated Transcriptomic, Metabolomic, and Physiological Analyses Reveal New Insights into Fragrance Formation in the Heartwood of Phoebe hui.

Phoebe hui is an extremely valuable tree that is the main source of the fragrant golden-thread nanmu wood. Although the fragrance of wood has been investigated in several trees, the potential substances and gene regulation mechanisms that are involved in fragrance formation are poorly understood. Here, three radial tissues, sapwood (SW), heartwood (HW), and the transition zone (TZ) in between them, were compared via integrative physiological, volatile-metabolomic, and transcriptomic analyses to identify the key metabolites and regulatory mechanisms involved in fragrance formation. During heartwood formation, gradual starch grain loss was accompanied by the deposition of lipids and extractives in the cell lumen. Extracts of terpenoids were synthesized and accumulated in the heartwood, including monoterpenoids (limonene and p-cymene) and sesquiterpenes (cubebene and guaiadiene); these were identified as being closely related to the special fragrance of the wood. Additionally, the expression of transcripts showed that the genes related to primary metabolism were specifically upregulated in the SW, whereas genes annotated in terpenoid biosynthesis were specifically upregulated in the HW. Therefore, we speculated that terpenoid biosynthesis occurs in situ in the HW via the HW formation model of Type-III (Santalum) using the precursors that were produced by primary metabolism in the SW. The expression levels of transcription factors (e.g., MYB, WRKY, and C2H2) acted as the major regulatory factors in the synthesis of terpenoids. Our results explain the special fragrance in P. hui and broaden the current knowledge of the regulatory mechanisms of fragrance formation. This work provides a framework for future research that is focused on improving wood quality and value.

Integrative Metabolomic and Transcriptomic Analysis Reveals the Mechanism of Specific Color Formation in Phoebe zhennan Heartwood.

Nanmu (Phoebe zhennan) is an extremely valuable tree plant that is the main source of famous "golden-thread nanmu" wood. The potential metabolites and gene regulation mechanisms involved in golden thread formation are poorly understood, even though the color change from sapwood to heartwood has been investigated in several tree plants. Here, five radial tissues from sapwood to heartwood were compared via integrative metabolomic and transcriptomic analysis to reveal the secondary metabolites and molecular mechanisms involved in golden thread formation. During heartwood formation, gradual starch grain loss is accompanied by the cell lumen deposition of lipids and color-related extractives. Extractives of 20 phenylpropanoids accumulated in heartwood, including cinnamic acids and derivatives, coumarin acid derivatives, and flavonoids, which were identified as being closely related to the golden thread. Phenylpropanoids co-occurring with abundant accumulated metabolites of prenol lipids, fatty acyls, steroids, and steroid derivatives may greatly contribute to the characteristics of golden thread formation. Additionally, the expression of nine genes whose products catalyze phenylpropanoid and flavonoids biosynthesis was upregulated in the transition zone, then accumulated and used to color the heartwood. The expression levels of transcription factors (e.g., MYB, bHLH, and WRKY) that act as the major regulatory factors in the synthesis and deposition of phenylpropanoid and flavonoids responsible for golden thread formation were also higher than in sapwood. Our results not only explain golden thread formation in nanmu, but also broaden current knowledge of special wood color formation mechanisms. This work provides a framework for future research focused on improving wood color.

Genome-wide investigation and expression profiling of polyphenol oxidase (PPO) family genes uncover likely functions in organ development and stress responses in Populus trichocarpa.

BACKGROUND: Trees such as Populus are planted extensively for reforestation and afforestation. However, their successful establishment greatly depends upon ambient environmental conditions and their relative resistance to abiotic and biotic stresses. Polyphenol oxidase (PPO) is a ubiquitous metalloproteinase in plants, which plays crucial roles in mediating plant resistance against biotic and abiotic stresses. Although the whole genome sequence of Populus trichocarpa has long been published, little is known about the PPO genes in Populus, especially those related to drought stress, mechanical damage, and insect feeding. Additionally, there is a paucity of information regarding hormonal responses at the whole genome level. RESULTS: A genome-wide analysis of the poplar PPO family was performed in the present study, and 18 PtrPPO genes were identified. Bioinformatics and qRT-PCR were then used to analyze the gene structure, phylogeny, chromosomal localization, gene replication, cis-elements, and expression patterns of PtrPPOs. Sequence analysis revealed that two-thirds of the PtrPPO genes lacked intronic sequences. Phylogenetic analysis showed that all PPO genes were categorized into 11 groups, and woody plants harbored many PPO genes. Eighteen PtrPPO genes were disproportionally localized on 19 chromosomes, and 3 pairs of segmented replication genes and 4 tandem repeat genomes were detected in poplars. Cis-acting element analysis identified numerous growth and developmental elements, secondary metabolism processes, and stress-related elements in the promoters of different PPO members. Furthermore, PtrPPO genes were expressed preferentially in the tissues and fruits of young plants. In addition, the expression of some PtrPPOs could be significantly induced by polyethylene glycol, abscisic acid, and methyl jasmonate, thereby revealing their potential role in regulating the stress response. Currently, we identified potential upstream TFs of PtrPPOs using bioinformatics. CONCLUSIONS: Comprehensive analysis is helpful for selecting candidate PPO genes for follow-up studies on biological function, and progress in understanding the molecular genetic basis of stress resistance in forest trees might lead to the development of genetic resources.

Clinical features, treatments and outcomes of calcinosis in adult patients with dermatomyositis: a single cohort study.

OBJECTIVE: The occurrence of calcinosis cutis as a clinical feature of dermatomyositis in adult patients is not well understood. Cohort studies of adult patients with calcinosis are rare. We systematically describe the clinical features, treatments and outcomes of adult patients with calcinosis. METHODS: We initially enrolled 627 adult DM patients. Of those enrolled, 35 (5.6%) were found to have calcinosis. We analysed the clinical features associated with calcinosis in this subgroup. The risk factors associated with calcinosis were analysed using the Poisson regression model. RESULTS: Multivariate analysis showed that a younger age at disease onset [odds ratio (OR) = 0.945, 95% CI 0.925, 0.966, P < 0.001], dysphagia (OR = 2.609, 95% CI 1.189, 5.728, P = 0.017), skin ulcer (OR = 5.705, 95% CI 3.041, 10.705, P < 0.001) and the presence of anti-nuclear matrix protein 2 antibody (OR = 5.917, 95% CI 2.754, 12.714, P < 0.001) were independently associated with calcinosis. In both the low- and high-dose prednisone treatment groups, no difference in treatment response was seen between the bisphosphonate treatment group and the group not receiving bisphosphonate treatment (P = 1.000 and P = 0.375, respectively). A follow-up study revealed that the mortality rate of the calcinosis group was 5.7%. Additionally, 60.6% of the cases had a chronic polycyclic disease course and 17.1% had mild complications secondary to calcinosis. CONCLUSION: Calcinosis is an uncommon, but significant clinical feature in adult patients with DM. Bisphosphonates were not found to effectively treat calcinosis, however, the overall health outcomes of adult DM patients with calcinosis were favourable.

First report of brown leaf spot on Juglans sigillata caused by Ophiognomonia leptostyla in Sichuan, China.

Juglans sigillata Dode (Iron walnut) is mostly distributed in southwestern China, and valued for wood and nuts (Feng et al. 2018). In April 2020, we surveyed a walnut garden located in Baisha Town, Wanyuan City, (Sichuan, China), where brown spot symptoms were observed on leaves of ten trees among of 100 plants, and this disease can result in a reduced growth potential when trees are severely infected. Necrotic and subcircular lesions with conidiamata were observed on diseased leaves. Symptomatic leaves were collected and taken back to the laboratory forfurther analysis. Using the single spore isolation technique developed by Chomnunti et al. (2014), five isolates were grown from the infected leaves on Potato Dextrose Agar medium (PDA). The five isolates had similar colony morphology, which was initially white, suborbicular, gradually turning yellowish with black spots, developing fluffy aerial mycelium. Morphological characteristics were examined using light microscopy on the PDA. Conidiogenous cells were subcylindrical to cylindrical, or ampulliform, hyaline, rarely branched. Macroconidia were lunate, reniform, hyaline, 1-3-septate, mostly 1-septate, distinctly constricted at the septum, the basal cell was bluntly rounded, the apical cell had an acute end, and the basal cell was equal to or larger than the apical cell, measuring 22 to 40.5 × 2.5 to 8.3 µm (mean = 32 × 6.2 µm, n = 50). Microconidia were botuliform, or subfusiform, hyaline, both ends were rounded, straight or curved, aseptate, and measured 10 to 28.5 × 1.9 to 3.7 µm (mean= 17.2 × 2.7 µm, n = 20). A multilocus approach was conducted for precise identification of a representative isolate SICAUCC 20-0012. The internal transcribed spacer regions (ITS), guanine nucleotide-binding protein subunit beta gene (MS204), and translation elongation factor 1-alpha (tef1-α) of isolate SICAUCC 20-0012 were amplified and sequenced as described by Sogonov et al. (2008) and Walker et al. (2012a). GenBank Accession Nos. for ITS, MS204, and tef1-α are MW250303, MW246773, and MW246775, respectively. Phylogenetic analyses showed 100% support with Ophiognomonia leptostyla (Fr.) Sogonov, and the morphology was consistent with the asexual stage of O. leptostyla documented by Walker et al. (2012b). To test Koch's postulates, five healthy plants of J. sigillata (2- to 3-year-old) with 5-8 leaves per plant were inoculated with conidial suspensions (104 conidia/mL) after wounded with a small pin as described by Desai et al. (2019), and the same number of healthy plants were wounded and sprayed with sterile distilled water as controls. Plants were sprayed regularly with distilled water every day and placed in a growth chamber at 25℃ with a 12-h fluorescent light/dark regimen. After 15 days, typical brown spot symptoms developed on inoculated leaves, but not on the controls. The fungus O. leptostyla was reisolated from the lesion as described above but not from non-inoculated leaves. O. leptostyla has been reported on some walnut trees; for example: J. ailantifolia, J. californica, J. cinerea, J. hindsii, J. major, J. mandshurica, J. nigra, and J. regia (Farr & Rossman 2020). However, to our knowledge, this is the first report of O. leptostyla causing brown leaf spot on J. sigillata. J. sigillata is an economically important tree in southwest China, and fungicide treatments should be considered to prevent the spread of this fungus before it becomes more widespread. Chunlin Yang, Yu Deng, and Feihu Wang contributed equally to this work. This research was supported by the Key Research and Development Project of Sichuan Province (2021YFYZ0032).

First Report of Brown Leaf Spot of Juglans hybrid Caused by Ophiognomonia leptostyla in China.

"Chuanzao 2" is a walnut variety derived from the hybridization of Juglans regia L. and J. sigillata Dode distributed in southwest China, where it is an economically important tree species in rural regions (Xiao et al. 2012). In April 2020, the variety in a walnut garden showed symptoms of brown leaf spot in Beishan Town (107°21'43.93″E, 31°28'12.34″N), Dazhou City in Sichuan, China, with 5% to 10% of leaves per plant affected (5 plants). Symptomatic leaves showed brown to dark brown spots (2 to 5 mm) with a dark brown to black halo and grayish-tan center. The spots were subcircular to irregular in shape, and gradually expanded and formed necrotic spots. A single conidium isolation was performed (Senanayake et al. 2020) and transferred to Potato Dextrose Agar (PDA). Five isolates were obtained from five different infected leaves. Colonies of five isolates were subcircular, erose or dentate, flat or effuse, white initially, gradually becoming yellowish with white margins, developed and fluffy aerial mycelia, and conidiogenensis was produced underneath mycelia after 25-days-incubation. Conidiogenous cells were subcylindrical to cylindrical, or irregular in shape, and hyaline. Macroconidia were lunate, reniform, hyaline, basal cell bluntly rounded, apical cell with acute end, 1-septate, rarely aseptate, sometimes slightly constricted at septum, basal cell equal or larger than apical cell, and measured 16.5 to 30.5 × 5 to 8.5 µm (mean = 23.2 × 6.3 µm, n = 50). Microconidia were not observed. These morphological characteristics resembled those of Ophiognomonia leptostyla (Fr.) Sogonov (Walker et al. 2012a). For molecular identification, genomic DNA (isolates SICAUCC 21-0008 and SICAUCC 21-0010) was extracted, and the internal transcribed spacers (ITS) region, guanine nucleotide-binding protein subunit beta (MS204) gene, and translation elongation factor 1-alpha (tef1-α) were amplified and sequenced by using the primers ITS5/ITS4 (White et al. 1990), E1F1/E5R1a (Walker et al. 2012a), and EF1-728F/EF1-1567R (Walker et al. 2012b), respectively. Phylogenetic analyses (maximum likelihood) based on a combined dataset showed 100% bootstrap support values in a clade with O. leptostyla. The sequences of ITS, MS204, and tef1-α genes were deposited in GenBank with accession numbers MW493111/MZ026300, MW495270/MZ031975, and MW495271/MZ031974, respectively. To fulfill Koch's postulates, five healthy hybrid plants (2 to 3 years old) with 5 to 8 leaves per plant were spray inoculated with conidium suspensions (104 conidia/mL; isolate SICAUCC 21-0008) prepared from 40-days-old cultures onto the wounded sites via pin-prick inoculation. Similarly, five noninoculated plants sprayed with sterile water served as controls. Plants were placed in a growth chamber at 25℃ on a 12-h fluorescent light/dark regime and daily sprayed with sterile distilled water. After two weeks, observed symptoms were similar to those from natural infections. No disease symptoms were found on control plants. The fungus O. leptostyla was reisolated from the diseased leaves and characterized morphologically. O. leptostyla is a global pathogen and has been reported to cause the leaf spot in many walnut trees, viz. J. ailantifolia, J. californica, J. cinerea, and J. major, etc. To our knowledge, this is the first report of O. leptostyla causing brown leaf spot on Juglans hybrid (J. regia × J. sigillata) in China. The increasing risk of this pathogen in the walnut-growing areas of Sichuan Province of China needs a further exploration and outreach effort to develop effective control measures. Chunlin Yang, Feng Liu, and Qian Zeng contributed equally to this paper.

Genome-Wide Investigation of the NF-X1 Gene Family in Populus trichocarpa Expression Profiles during Development and Stress.

Poplar are planted extensively in reforestation and afforestation. However, their successful establishment largely depends on the environmental conditions of the newly established plantation and their resistance to abiotic as well as biotic stresses. NF-X1, a widespread transcription factor in plants, plays an irreplaceable role in plant growth, development, and stress tolerance. Although the whole genome sequence of Populus trichocarpa has been published for a long time, little is known about the NF-X1 genes in poplar, especially those related to drought stress, mechanical damage, insect feeding, and hormone response at the whole genome level. In this study, whole genome analysis of the poplar NF-X1 family was performed, and 4 PtrNF-X1 genes were identified. Then, bioinformatics analysis and qRT-PCR were applied to analyze the gene structure, phylogeny, chromosomal localization, gene replication, Cis-elements, and expression patterns of PtrNF-X1genes. Sequence analysis revealed that one-quarter of the PtrNF-X1 genes did not contain introns. Phylogenetic analysis revealed that all NF-X1 genes were split into three subfamilies. The number of two pairs of segmented replication genes were detected in poplars. Cis-acting element analysis identified a large number of elements of growth and development and stress-related elements on the promoters of different NF-X1 members. In addition, some PtrNF-X1 could be significantly induced by polyethylene glycol (PEG) and abscisic acid (ABA), thus revealing their potential role in regulating stress response. Comprehensive analysis is helpful in selecting candidate NF-X1 genes for the follow-up study of the biological function, and molecular genetic progress of stress resistance in forest trees provides genetic resources.

Identification of a novel autoantibody against heat shock factor 1 in idiopathic inflammatory myopathy.

OBJECTIVES: Myositis autoantibodies show great utility in the diagnosis and clinico-serological phenotyping of idiopathic inflammatory myopathy (IIM). We identified a novel autoantibody against heat shock factor 1 (HSF1) and further evaluated its disease specificity and clinical significance in IIM patients. METHODS: A human protein microarray was used to identify autoantibodies in myositis sera. ELISA, immunoblot and dot blot assays were applied to examine anti-HSF1 autoantibodies in IIM patients and controls. Immunofluorescence was used to detect HSF1 expression in muscle tissues. RESULTS: Anti-HSF1 was identified as a novel autoantibody by protein microarray and the seroreactivity was confirmed by immunoprecipitation, ELISA, immunoblot and dot blot assays. Anti-HSF1 autoantibodies were present in 64/581 (11.0%) IIM, 4/37 (10.8%) rheumatoid arthritis, 5/40 (12.5%) primary Sjögren's syndrome, 2/40 (5%) systemic lupus erythematosus, while largely negative in healthy controls. Anti-HSF1 autoantibodies were significantly associated with pruritus, hypergammaglobulinaemia, and elevated erythrocyte sedimentation rate in IIM patients. Anti-HSF1 autoantibodies were more prevalent in cancer-associated myositis (CAM) compared to non-CAM patients (17.2% vs. 7.5%, p=0.009), nevertheless were undetectable in cancer controls. Meanwhile, cross-sectional and longitudinal analyses revealed positive correlations between anti-HSF1 levels and disease activity in IIM patients without cancer. Additionally, increased expression of HSF1 was found in regenerating muscle cells of myositis muscle tissues. CONCLUSIONS: These data reveal anti-HSF1 as a new autoantibody associated with CAM in IIM. The autoimmunity against HSF1 may be involved in the immunopathogenesis of myositis.

Sex-specific responses of Populus deltoides to interaction of cadmium and salinity in root systems.

More research about branch order-specific accumulation of toxic ions in root systems is needed to know root branch-related responses in growth and physiology. In this study, we used Populus deltoides females and males as a model to detect sex-specific differences in physiology, biochemistry, ultrastructure of absorbing roots and distribution of toxic ions in heterogeneous root systems under Cd, salinity and combined stress. Healthy annual male and female plants of P. deltoides were cultivated in soils including 5 mg kg-1 of Cd, 0.2% (w/w) of NaCl and their combination for a growth season. Our results are mainly as follows: (1) females suffered more growth inhibition, root biomass decline, root viability depression, and damage to distal root cells, but lower ability to scavenge reactive oxygen species (ROS) than the males under all stresses; (2) In both sexes, salinity adopted in the present study caused more significant negative effects on growth and organelles integrity than Cd stress, while interaction treatment did not induced a further depression in growth or more impairments in root cells of both sexes in comparison to salinity, indicating influence of combined stress was not equal simply to a superposition of the effects caused by single factors; (3) Cd and Na accumulation in root systems is highly heterogeneous and branch order-specific, with lower-order roots containing more Cd2+ but less Na+, and higher-order roots accumulating more Na+ but less Cd2+. Besides, it is noteworthy that females accumulated more Cd2+ in 1-2 order roots and more Na+ in 1-3 order roots than males under the interaction treatment. These results indicated that strategies in toxic ions accumulation in heterogeneous root systems of P. deltoides was highly branch order-specific, and may closely correlate with sex-specific root growth and physiological responses to the interaction of Cd and salinity.