A harmonized global gridded transpiration product based on collocation analysis.

Transpiration (T) is pivotal in the global water cycle, responding to soil moisture, atmospheric stress, climate changes, and human impacts. Therefore, establishing a reliable global transpiration dataset is essential. Collocation analysis methods have been proven effective for assessing the errors in these products, which can subsequently be used for multisource fusion. However, previous results did not consider error cross-correlation, rendering the results less reliable. In this study, we employ collocation analysis, taking error cross-correlation into account, to effectively analyze the errors in multiple transpiration products and merge them to obtain a more reliable dataset. The results demonstrate its superior reliability. The outcome is a long-term daily global transpiration dataset at 0.1°from 2000 to 2020. Using the transpiration after partitioning at FLUXNET sites as a reference, we compare the performance of the merged product with inputs. The merged dataset performs well across various vegetation types and is validated against in-situ observations. Incorporating non-zero ECC considerations represents a significant theoretical and proven enhancement over previous methodologies that neglected such conditions, highlighting its reliability in enhancing our understanding of transpiration dynamics in a changing world.

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.

Identification and variation analysis of the composition and content of essential oil and fragrance compounds in Phoebe zhennan wood at different tree ages.

Wood essential oil and wood products with special fragrances are high value-added forest products. Despite the availability of essential oil and volatile organic compounds (VOCs) from Phoebe zhennan wood, their variation and dependence on tree age have not been examined. After essential oil extraction and wood processing, the yields and compositions of essential oils and VOCs in wood from P. zhennan trees of different ages (10a, 30a, and 80a) were determined. The yield of essential oil from 30a wood was significantly greater than that from 10a and 80a wood. Liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) revealed 672 and 41 volatile compounds, respectively, in the essential oil and wood, the majority of which exhibited large fluctuations in relative content and composition depending on tree age. Sesquiterpenoids, fatty acids and conjugates may greatly contribute to the main components of essential oil from wood. Almost all major sesquiterpenoid compounds, such as caryophyllene α-oxide, eudesmo, and cubebene, were identified in the essential oils from the 30a and 80a wood, and their relative contents were much greater than those in the 10a wood. The main components of the wood fragrance were sesquiterpenoids. The types and relative contents of sesquiterpenoids from wood increased with tree age. These results suggest that choosing wood from trees of a suitable age will significantly improve the efficiency of wood utilization.

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.

Iridium-catalyzed selective arylation of B(6)-H of 3-aryl-o-carboranes with arylboronic acid via direct B-H activation.

This work discloses an iridium-catalyzed selective arylation of B(6)-H of 3-Ar-o-carboranes with arylboronic acid via direct B-H activation for the first time. A series of unsymmetric and symmetric 3,6-diaryl-o-carboranes decorated with diverse active groups have been synthesized with moderate to excellent yields under mild conditions. This work offers an efficient approach for selective arylation of B(6)-H with arylboronic acid and has important value for selective functionalization of o-carboranes.

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.

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.

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.

Upregulation of the CD155-CD226 Axis Is Associated With Muscle Inflammation and Disease Severity in Idiopathic Inflammatory Myopathies.

BACKGROUND AND OBJECTIVES: The CD155-CD226/T-cell Ig and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) pathway plays a critical role in regulating T-cell responses and is being targeted clinically. However, research on the role of this pathway in autoimmune diseases is limited. This study aimed to investigate the expression and tissue-specific roles of CD155-CD226/TIGIT pathway molecules in the inflamed muscles of patients with idiopathic inflammatory myopathies (IIMs). METHODS: Immunohistochemistry, Western blot analysis, and polychromatic immunofluorescence staining were performed to examine the expression of CD155, CD226, and TIGIT in skeletal muscle biopsies from 30 patients with dermatomyositis (DM), 10 patients with amyopathic DM (ADM), 20 patients with immune-mediated necrotizing myopathy (IMNM), 5 patients with dysferlinopathy, and 4 healthy controls. Flow cytometry analysis was used to analyze the functions of T cells with different phenotypes. RESULTS: Strong expression of CD155 was observed in patients with DM and IMNM, while its expression was largely negative in those with ADM and dysferlinopathy and healthy controls. The costimulatory receptor CD226 was highly expressed on muscle-infiltrating cells, while the coinhibitory receptor TIGIT was expressed at low levels. These infiltrating CD226+ cells were mainly activated effector T cells that localized adjacent to CD155-expressing myofibers, but were faintly detectable within the muscle fascicles lacking CD155. A strong positive correlation between CD155 and CD226 expression scores was also observed. Polychromatic immunofluorescence staining revealed that CD155+ muscle cells coexpressed major histocompatibility complex classes I and II, and tumor necrosis factor alpha expression was detected in CD226+ T cells at their close sites with the myofibers. Furthermore, the expression levels of CD155 and CD226 showed a positive correlation with creatine kinase, lactate dehydrogenase, and the muscle histopathology damage scores and an inverse correlation with the Manual Muscle Testing-8 scores. In addition, CD155 and CD226 expressions were significantly decreased in representative patients who achieved remission posttreatment. DISCUSSION: These findings demonstrate that the CD155-CD226 axis is highly activated in inflamed muscle tissues of patients with IIM and is associated with muscle disease severity. Our data uncover the immunopathogenic role of the axis in the pathology of IIMs.

Volatile Metabolites from Brevundimonas diminuta and Nematicidal Esters Inhibit Meloidogyne javanica.

Brevundimonas diminuta is broadly distributed in terrestrial and aquatic environments and has various biological activities. In this study, we found that B. diminuta exhibited nematicidal activity against the plant root-knot nematode, Meloidogyne javanica. A total of 42 volatile organic compounds (VOCs) from B. diminuta were identified using gas chromatography-mass spectrometry (GC-MS). The nematicidal activity of the 10 main VOCs was tested against M. javanica. Butyl butanoate (4 µL) caused the mortality of 80.13% of M. javanica after 4 h. The nematicidal activity of an additional 38 butyl-butyrate-like volatile esters was also investigated. Of these, seven had strong nematicidal activity against M. javanica, five of which showed egg-hatching inhibitory activity. This study is the first to report that butyl butanoate, ethyl 2-methylbutanoate, ethyl 4-methylpentanoate, ethyl pent-4-enoate, and methyl undecanoate have nematicidal activity against M. javanica. The results indicated that B. diminuta could serve as a candidate microorganism for the biocontrol of plant root-knot nematodes, showing that volatile esters have great potential as nematicides.

Identification and pathogenicity analysis of leaf brown spot of Juglans regia in China.

English walnut (Juglans regia), has high economic and ecological value. As an important tree species for eliminating poverty, it is planted in many Provinces of China. In 2021, new pathogenic fungi were observed in English walnut in Guangyuan City, Sichuan Province, China. The initial symptom of leaf infection is that the leaves are covered with small black spots, which gradually expand into larger brown spots. Most of the spots appeared at the edges of the leaves, and yellow whorls were observed at the junction between the spots and the healthy leaves. The pathogenic fungi were isoalted form collecting disease samples and purified by single-spore culturing. In vitro and field experiments showed that the pathogen could cause brown spots on walnut leaves. The inoculation experiment showed that the symptoms in the field experiment were the same as those observed on the spot; however, slight differences were observed in the in vitro experiment. Ten isolates were obtained from walnut leaves with brown spot symptoms, and these were further characterized based on morphology and DNA sequencing. ITS (internal transcribed spacer), LSU (large sub-unit rDNA), rpb2 (second largest subunit of RNA polymerase) and tub2 (beta-tubulin) gene regions were used to construct phylogenetic trees and determine the evolutionary relationships among the collected strains. The isolate was identified as Nothophoma quercina by morphological and polygene analyses. As far as we are aware, the brown spots on walnut leaves caused by N. quercina is the first report of its kind.

Integrating physiological and transcriptome analyses clarified the molecular regulation mechanism of PyWRKY48 in poplar under cadmium stress.

WRKY transcription factors (TFs) play an important role in regulating plant growth and responses to environmental stress. However, the molecular mechanism of WRKY to cadmium (Cd) stress is unclear, which prevents phytoremediation of Cd-contaminated soil from widely application. To determine the underlying mechanism, PyWRKY48-overexpressing poplars were obtained (OE-32 and OE-67) to study the Cd tolerance and accumulation in poplars. Results showed that the Cd content in the aboveground part of the two transgenic poplar lines were 1.57 and 1.99 times higher than that of wild type (WT), and lateral roots, GSH, PCs content and GST activity increased significantly. RNA-seq. data about transgenic and WT poplars revealed that 2074 differentially expressed genes (DEGs) in roots, 4325 in leaves, and 499 in both tissues. And these DEGs were mainly concentrated in ABC transport protein (PaABC), heavy-metal binding protein (PaHIPP), and transportation and loading of xylem (PaNPF, PaBSP) proteins, and they enhanced Cd accumulation. Meanwhile, PyWRKY48 increased the Cd tolerance of transgenic poplars by up-regulating the expression of PaGRP, PaPER and PaPHOS, which encode cell wall proteins, antioxidant enzyme, and heavy metal-associated proteins, respectively. In addition, overexpression PyWRKY48 promoted poplar growth by increasing the chlorophyll and carotenoid content. ENVIRONMENTAL IMPLICATION: This study generated PyWRKY48-overexpressing poplars and functionally verified them in Cd-contaminated soil, to analyze the effects of the gene on poplar growth, Cd tolerance and Cd accumulation. RNA seq. data revealed that several genes are involved in Cd exposure. This may provide a strong molecular basis and new ideas for improving the phytoremediation efficiency of Cd-contaminated soils. Importantly, the transgenic poplars grew better and accumulated more Cd than the wild-type. Therefore, PyWRKY48-overexpressing poplars could be considered useful for mitigating environmental pollution.

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.

Iridium-catalyzed selective amination of B(4)-H for the synthesis of o-carborane-fused indolines.

An iridium-catalyzed selective amination of B(4)-H via dehydrogenative cross-coupling of B-H/N-H bonds for the synthesis of o-carborane-fused indolines has been developed for the first time. Various types of unprecedented o-carborane-fused indolines have been synthesized, which would be potential candidates for applications in drug discovery, pharmaceutical chemistry and functional materials. This work offers a valuable reference for the designing and synthesis of o-carborane-fused heterocycles.

The effects of fertility and synchronization variation on seed production in two Chinese fir clonal seed orchards.

Variations in fertility and synchronization information is fundamental to seed orchard management. Our objective was to determine clonal variation and stability in strobili production, phenology, synchronization, and seed production in two generation clonal seed orchards (CSO) of Chinese fir. The number of female and male strobili and the phenology of 42 clones in both the 2.0- and 2.5-generation clonal seed orchards were investigated and recorded to calculate the variation and stability of fertility and synchronization. In both seed orchards, an obvious variation in gamete contribution was found among clones, indicating deviation from random mating. Female receptivity was in the pollen shedding stage, which is favorable to pollination. However, low synchronization (mean POij = 0.283) between clones indicated low overlap between female receptivity and pollen shedding. A higher POij value within clones than within outcrossing combinations indicated a high risk of selfing in two seed orchards, particularly for early- and late-flowering clones. The number of female strobili and POij (as female) significantly influence seed production. Overall, fertility and synchronization variation had notable consequences for seed production. Scientific genetic management is indispensable for promoting fertility uniformity and synchronization to obtain maximal genetic gain.

Screen-printed highly stretchable and stable flexible electrodes with a negative Poisson's ratio structure for supercapacitors.

Flexible power sources are crucial to developing flexible electronic systems; nonetheless, the current poor stretchability and stability of flexible power sources hinder their application in such devices. Accordingly, the stretchability and fatigue stability of flexible power sources are crucial for the practical application of flexible electronic systems. In this work, a flexible electrode with an arc-shaped star concave negative Poisson's ratio (NPR) structure is fabricated through the screen printing process. Using the combination of finite element analysis (FEA) and tensile tests, it is proven that the arc-shaped star concave NPR electrode can effectively reduce the maximum tensile stress and increase the maximum elongation (maximum elongation 140%). Furthermore, the flexible electrodes prepared in this study are assembled into all-solid-state symmetric supercapacitors (SSCs), and their electrochemical properties are tested. The SSC prepared in this study has a high areal capacitance of 243.1 mF cm-2. It retains 89.25% of its initial capacity after 5000 times of folding and can maintain a stable output even in extreme deformation, which indicates that the SSC prepared in this study has excellent stability. The SSC with the advantages mentioned above obtained in this study is expected to provide new opportunities to develop flexible electronic systems.

Long-Term Outcomes and Prognosis Factors in Patients With Idiopathic Inflammatory Myopathies Based on Myositis-Specific Autoantibodies: A Single Cohort Study.

OBJECTIVE: This study was undertaken to investigate the long-term survival rates and prognostic factors in patients with idiopathic inflammatory myopathies (IIMs) based on myositis-specific antibody (MSA) stratification. METHODS: Exactly 628 patients with an IIM were included. Kaplan-Meier survival curves, univariate, and multivariate Cox regression were used to analyze the outcomes and risk factors. RESULTS: The cumulative 1-, 5-, and 10-year survival rates for IIM patients overall were 91.4%, 82.8%, and 75.6%, respectively. The survival rate in the MSA subset was significantly different (P < 0.001). The 1- and 10-year survival rates in the anti-melanoma differentiation-associated protein 5 (anti-MDA-5)-positive subgroup were 79.5% and 58.5%, respectively, which were the lowest among all subgroups. The 10-year survival rate of anti-signal recognition particle (anti-SRP)-positive patients was the highest (96.4%). Independent risk factors that impacted the long-term prognosis for IIM patients included rapidly progressive interstitial lung disease (RP-ILD), malignancy, and elevated serum ferritin levels (hazard ratio [HR] 17.47, 20.36, and 9.15, respectively, P < 0.01), whereas disease duration was a protective factor (HR 0.27, P = 0.003). Among these subsets, the strongest independent risk factor for death in the anti-MDA-5-positive subgroup was RP-ILD (HR 3.4, P = 0.017). Malignancy was an independent risk factor in the anti-aminoacyl-tRNA synthetase antibody-positive, anti-transcription intermediary factor 1γ-positive, and MSA-negative subgroups (HR 46.69, 6.65, and 4.48, respectively; P < 0.001). RP-ILD was also a risk factor in the prognosis of individuals in the MSA-negative subgroup (HR 72.28, P < 0.001). CONCLUSION: Despite favorable overall survival in patients with IIM, the anti-MDA-5-positive subgroup had the highest mortality rate among all MSA subgroups, highlighting the distinctive prognosis for patients with different MSAs. RP-ILD and malignancy are the most common causes of death in IIM patients.

Comparative analysis of nitrogen content and its influence on actinorhizal nodule and rhizospheric microorganism diversity in three Alnus species.

Alnus spp. (alder) are typical nonleguminous nitrogen-fixing trees that have a symbiotic relationship with Frankia. To explore the differences in nitrogen-fixing microorganisms between three alders (A. cremastogyne, A. glutinosa, and A. formosana) with different chromosome ploidies, the community structure and compositional diversity of potential nitrogen-fixing microorganism in root nodules and rhizosphere soil were comparatively analyzed using 16S rRNA and nitrogenase (nifH) gene sequencing. The nitrogen contents in the root nodules and rhizosphere soil were also determined. The results showed that the contents of total nitrogen and nitrate nitrogen in the root nodules of the three alders are significantly higher than those in the rhizosphere soils, while the ammonium nitrogen content show the opposite trend. The family, genus, and species levels showed obviously differences between root nodules and rhizosphere soils, while there were no significant differences at the classification level between the three alders. At the phylum level, the dominant phyla from 16S rRNA and nifH gene data in the root nodules and rhizosphere soil of the three alders are phylum Actinomycetota and phylum Pseudomonadota, respectively. The LEfSe results showed that there are significant differences in the dominant groups in the root nodules and rhizosphere oil of the three alders. The relative abundances of dominant groups also showed obvious differences between the root nodules and rhizosphere soils of three alders. The relative abundances of Frankia and unclassified_Frankia in root nodules are obviously higher than those in rhizosphere soils, and their relative abundances in A. glutinosa root nodules are significantly higher than those in A. cremastogyne and A. formosana at the genus and species levels. The diversity of potential nitrogen-fixing microorganism from 16S rRNA and nifH gene data in the A. glutinosa root nodules and rhizosphere soils are all higher than those in A. cremastogyne and A. formosana. The results of functional prediction also showed that the OTUs for nitrogen fixation, nitrate respiration, and ureolysis in A. glutinosa root nodules are higher than those in the other two alders. Redundancy analysis revealed that the total nitrogen content mostly affects the Frankia community. Overall, there are significant differences in the community composition and structure of potential nitrogen-fixing microorganism in the root nodules and rhizosphere soils between the three alders. A. glutinosa showed a relatively stronger nitrogen fixation capacity than A. formosana and A. cremastogyne. The results help elucidates how the community structure and nitrogen-fixing ability of potential nitrogen-fixing microorganism differ between alder species and serve as a reference for applying Frankia to alder plantations.

Morphology and phylogeny of ascomycetes associated with walnut trees (Juglans regia) in Sichuan province, China.

In Sichuan province, walnuts, consisting of Juglans regia, Juglans sigillata, and the hybrid J. regia × J. sigillata, are commercially important edible nuts, and J. regia is the most widespread plant. To date, the diversity and distribution of fungi inhabiting on Juglans have not received enough attention, although there have been studies focusing on pathogens from fruit and stem. In order to update the checklist of fungi associated with Sichuan walnuts, a survey on fungi associated with the three Juglans species from 15 representative regions in Sichuan was conducted. In this article, ten fungi distributed in two classes of Ascomycota (Dothideomycetes and Sordariomycetes) were described based on morpho-molecular analyses, and two novel species, Neofusicoccum sichuanense and Sphaerulina juglandina, a known species of Ophiognomonia leptostyla, and seven new hosts or geographical records of Cladosporium tenuissimum, Diatrypella vulgaris, Helminthosporium juglandinum, Helminthosporium velutinum, Loculosulcatispora hongheensis, Periconia byssoides, and Rhytidhysteron subrufulum were included. Morphological descriptions and illustrations of these fungi are provided.

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.