Mutations across Diverse Domains of CjXDR1 Lead to Multidrug Resistance in Clarireedia jacksonii.

Recently, Clarireedia jacksonii has emerged as a significant pathogen threatening turfgrass, and its escalating resistance to multiple drugs often undermines field interventions. This study highlighted the critical role of the fungus-specific transcription factor CjXDR1 (formerly ShXDR1) in regulating multidrug resistance (MDR) in C. jacksonii. This was demonstrated through experiments involving CjXDR1-knockout and CjXDR1-complemented strains. Our sequence analysis revealed five mutations in CjXDR1: G445D, K453E, S607F, D676H, and V690A. All five gain-of-function (GOF) mutations were confirmed to directly contribute to MDR against three different classes of fungicides (propiconazole: demethylation inhibitor, boscalid: succinate dehydrogenase inhibitor, and iprodione: dicarboximide) using the genetic transformation system and in vitro fungicide-sensitivity assay. Comparative transcriptome analysis revealed that CjXDR1 and its GOF mutations led to the overexpression of downstream genes encoding a Phase I metabolizing enzyme (CYP68) and two Phase III transporters (CjPDR1 and CjAtrD) previously reported. Knockout mutants of CYP68, CjPDR1, CjAtrD, and double-knockout mutants of CjPDR1 and CjAtrD exhibited increased sensitivity to all three fungicides tested. Among these, the CYP68-knockout mutants displayed the highest sensitivity to propiconazole, while the CjPDR1 knockout mutant exhibited significantly increased sensitivity to all three fungicides. Double-knockout mutants of CjPDR1 and CjAtrD displayed greater sensitivity than the single knockouts. In conclusion, multiple GOF mutants in CjXDR1 contribute to MDR by upregulating the expression of CjPDR1, CjAtrD, and CYP68. This study enhances our understanding of the molecular mechanisms underlying MDR in plant pathogenic fungi, providing valuable insights into GOF mutation structures and advancing the development of antifungal drugs.

Varied sensitivity to boscalid among different Clarireedia species causing dollar spot in turfgrass.

Dollar spot, a highly destructive turfgrasses disease worldwide, is caused by multiple species within the genus Clarireedia. Previous research indicated varying sensitivity to boscalid among Clarireedia populations not historically exposed to succinate dehydrogenase inhibitors (SDHIs). This study confirms that the differential sensitivity pattern is inherent among different Clarireedia spp., utilizing a combination of phylogenetic analyses, in vitro cross-resistance assays, and genetic transformation of target genes with different mutations. Furthermore, greenhouse inoculation experiments revealed that the differential boscalid sensitivity did not lead to pathogenicity issues or fitness penalties, thereby not resulting in control failure by boscalid. This research underscores the importance of continuous monitoring of fungicide sensitivity trends and highlights the complexity of chemical control of dollar spot due to the inherent variability in fungicide sensitivity among different Clarireedia spp.

A rapid real-time PCR assay for detecting Microdochium paspali causing sparse leaf patch on seashore paspalum and in environmental samples.

BACKGROUND: Sparse leaf patch (SLP) is one of the most significant diseases affecting seashore paspalum (Paspalum vaginatum Sw.), caused by Microdochium paspali. Fast and accurate detection of this pathogen is crucial for effective disease management. However, conventional culture-based methods are time-consuming and often compromised by the presence of other saprophytic or endophytic fungi. RESULTS: In this study, we developed a real-time fluorescent quantitative (q)PCR method based on the internal transcribed spacer (ITS) region of the ribosomal RNA gene to rapidly detect and quantify M. paspali. The qPCR assay demonstrated the ability to detect all 12 tested isolates of M. paspali, with no cross-reactions observed when tested against 30 isolates of other fungal pathogens from turfgrass samples. The detection limit of the qPCR method was as low as 3.65 × 102 copies µL-1 of M. paspali genomic DNA, and the entire detection process could be completed within 1 h. The fluorescence signal was detectable in the leaf tissues of seashore paspalum without apparent disease symptoms as early as 24 h postinoculation with M. paspali. Moreover, the qPCR method successfully detected M. paspali in both asymptomatic and symptomatic turfgrass samples, including leaf, stem, root and rhizosphere soil, indicating that this assay can significantly enhance the detection of M. paspali. CONCLUSION: The study developed a rapid real-time qPCR assay for the detection of M. paspali causing SLP on seashore paspalum and in environmental samples, which has important implications for early warning and management of SLP. © 2024 Society of Chemical Industry.

Interfacial self-healing polymer electrolytes for long-cycle solid-state lithium-sulfur batteries.

Coupling high-capacity cathode and Li-anode with solid-state electrolyte has been demonstrated as an effective strategy for increasing the energy densities and safety of rechargeable batteries. However, the limited ion conductivity, the large interfacial resistance, and unconstrained Li-dendrite growth hinder the application of solid-state Li-metal batteries. Here, a poly(ether-urethane)-based solid-state polymer electrolyte with self-healing capability is designed to reduce the interfacial resistance and provides a high-performance solid-state Li-metal battery. With its dynamic covalent disulfide bonds and hydrogen bonds, the proposed solid-state polymer electrolyte exhibits excellent interfacial self-healing ability and maintains good interfacial contact. Full cells are assembled with the two integrated electrodes/electrolytes. As a result, the Li||Li symmetric cells exhibit stable long-term cycling for more than 6000 h, and the solid-state Li-S battery shows a prolonged cycling life of 700 cycles at 0.3 C. The use of ultrasound imaging technology shows that the interfacial contact of the integrated structure is much better than those of traditional laminated structure. This work provides an interesting interfacial dual-integrated strategy for designing high-performance solid-state Li-metal batteries.

Comparative genomics and transcriptome analysis reveals potential pathogenic mechanisms of Microdochium paspali on seashore paspalum.

The sparse leaf patch of seashore paspalum (Paspalum vaginatum Sw.) caused by Microdochium paspali seriously impacts the landscape value of turf and poses a challenge to the maintenance and management of golf courses. Little is known about the genome of M. paspali or the potential genes underlying pathogenicity. In this study, we present a high-quality genome assembly of M. paspali with 14 contigs using the Nanopore and Illumina platform. The M. paspali genome is roughly 37.32 Mb in size and contains 10,365 putative protein-coding genes. These encompass a total of 3,830 pathogen-host interactions (PHI) genes, 481 carbohydrate-active enzymes (CAZymes) coding genes, 105 effectors, and 50 secondary metabolite biosynthetic gene clusters (SMGCs) predicted to be associated with pathogenicity. Comparative genomic analysis suggests M. paspali has 672 species-specific genes (SSGs) compared to two previously sequenced non-pathogenic Microdochium species, including 24 species-specific gene clusters (SSGCs). Comparative transcriptomic analyses reveal that 739 PHIs, 198 CAZymes, 40 effectors, 21 SMGCs, 213 SSGs, and 4 SSGCs were significantly up-regulated during the process of infection. In conclusion, the study enriches the genomic resources of Microdochium species and provides a valuable resource to characterize the pathogenic mechanisms of M. paspali.

Enhancing the Initial Coulombic Efficiency of Sodium-Ion Batteries via Highly Active Na2 S as Presodiation Additive.

Recently, sodium-ion batteries (SIBs) have received considerable attention for large-scale energy storage applications. However, the low initial Coulombic efficiency of traditional SIBs severely impedes their further development. Here, a highly active Na2 S-based composite is employed as a self-sacrificial additive for sodium compensation in SIBs. The in situ synthesized Na2 S is wrapped in a carbon matrix with nanoscale particle size and good electrical conductivity, which helps it to achieve a significantly enhanced electrochemical activity as compare to commercial Na2 S. As a highly efficient presodiation additive, the proposed Na2 S/C composite can reach an initial charge capacity of 407 mAh g-1 . When 10 wt.% Na2 S/C additive is dispersed in the Na3 V2 (PO4 )3 cathode, and combined with a hard carbon anode, the full cell achieves 24.3% higher first discharge capacity, which corresponds to a 18.3% increase in the energy density from 117.2 to 138.6 Wh kg-1 . Meanwhile, it is found that the Na2 S additive does not generate additional gas during the initial charging process, and under an appropriate content, its reaction product has no adverse impact on the cycling stability and rate performance of SIBs. Overall, this work establishes Na2 S as a highly effective additive for the construction of advanced high-energy-density SIBs.

Differentially expression analyses in fruit of cultivated and wild species of grape and peach.

Through agronomic traits and sequencing data, the cultivated and wild varieties of grapes and peaches were analyzed and compared in terms of fruit size, fruit flavor, fruit resistance, and fruit color. Cultivated grapes and peaches have advantages in fruit size, soluble sugar content, sugar and acid ratio, etc. Wild grapes and peaches have utility value in resistance. The results showed that there were 878 and 301 differentially expressed genes in cultivated and wild grapes and peaches in the three growth stages, respectively based on the next-generation sequencing study. Ten and twelve genes related to the differences between cultivated and wild grapes and peaches were found respectively. Among them, three genes, namely chalcone synthase (CHS), glutathione S-transferase (GST) and malate dehydrogenase (MDH1) were present in both cultivated and wild grapes and peaches.

Ion Conduction in Composite Polymer Electrolytes: Potential Electrolytes for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are expected to become alternatives to lithium-ion batteries (LIBs) as next-generation rechargeable batteries, owing to abundant sodium sources and low cost. However, SIBs still use liquid organic electrolytes (LOEs), which are highly flammable and have the tendency to leak. Although inorganic solid electrolytes (ISEs) and solid polymer electrolytes (SPEs) have been investigated for many years, given their higher safety level, neither of them is likely to be commercialized because of the rigidity of ISEs and the low room-temperature ionic conductivity of SPEs. During the last decade, composite polymer electrolytes (CPEs), composed of ISEs and SPEs, exhibiting both relatively high ionic conductivity and flexibility, have gained much attention and are considered as promising electrolytes. However, the ionic conductivities of CPEs are still unsatisfactory for practical application. Hence, this Review focuses on the principle of sodium ion conductors and particularly on recent investigations and development of CPEs.

Genome Resources for Four Clarireedia Species Causing Dollar Spot on Diverse Turfgrasses.

Dollar spot (DS) is a destructive fungal disease impacting almost all warm- and cool-season turfgrasses worldwide. Multiple fungal species in the genus Clarireedia are causal agents of DS. Here, we present whole-genome assemblies of nine fungal isolates in the genus Clarireedia, including four species (C. paspali, C. hainanense, C. jacksonii, and C. monteithiana) causing DS on seashore paspalum (Paspalum vaginatum Sw.), creeping bentgrass (Agrostis stolonifera L.), and Kentucky bluegrass (Poa pratensis L.) in China. This work provides valuable baseline genomic data to support further research and management of DS pathogens on turfgrasses.

A one-step multiplex PCR assay for the detection and differentiation of four species of Clarireedia causing dollar spot on turfgrass.

BACKGROUND: Dollar spot (DS) is one of the most destructive and economically important diseases of cool- and warm-season turfgrasses worldwide. A total of six species causing DS disease in the genus Clarireedia have been described, and four of them have been reported to be distributed countrywide in China. Identification of different species of Clarireedia is a prerequisite for the effective management of DS disease. RESULTS: Here we report a novel polymerase chain reaction (PCR)-based method for the detection and differentiation of the four species of Clarireedia associated with DS on turfgrass in China: C. jacksonii, C. paspali, C. monteithiana and C. hainanense. Species-specific genes were identified for each species by comparative genomics analysis. Four primer pairs were designed and mixed to amplify species-specific PCR fragments with differential sizes for the four species of Clarireedia in a single multiplex PCR assay. No PCR products were generated from the DNA templates of other common fungal pathogens associated with multiple turfgrass diseases. The multiplex PCR method developed can be used for the rapid and accurate detection and differentiation of the four species of Clarireedia from pure cultures as well as from infected turfgrass blades with DS symptoms. CONCLUSION: The study developed a one-step multiplex PCR assay for the detection and differentiation of four species of Clarireedia causing DS on turfgrass in China, which will have important implications for DS management in China and worldwide. © 2022 Society of Chemical Industry.

Distribution and Prevalence of Plant-Parasitic Nematodes of Turfgrass at Golf Courses in China.

We sampled 127 turfgrass soil samples from 33 golf courses in NC, EC, and SC for plant-parasitic nematodes (PPNs). PPNs were extracted from soil samples using the shallow dish method and were identified at the genus or species levels with a combination of morphological and molecular methods. The results revealed 41 species of nematode belonging to 20 genera and 10 families. Nine genera are new records of PPNs associated with turfgrass in China. The PPNs show strong geographical distributions. Of the 20 genera, Helicotylenchus, Paratrichodorus, Hoplolaimus, Meloidogyne, Hemicriconemoides, and Mesocriconema showed higher infestation and frequency, and most of these genera had numbers in soil samples above established damage thresholds. Four golf courses had soil samples with PPNs > 30%, indicating the potential for nematode damage. The biodiversity indices H', SR, J', λ, and H2 showed significant differences among different regions and turfgrass species; H', SR, J', and H2 were significantly higher in EC than in NC and SC, while λ was lowest in EC. Creeping bentgrass had the highest H', SR, J', and H2 and the lowest λ in comparison with seashore paspalum and hybrid bermudagrass. These findings provide baseline information on the occurrence of turfgrass-associated PPNs in China, and have important implications for the effective management of PPNs causing damage on turfgrass.

Analysis of the ignition of hydrogen/air mixtures induced by a hot particle.

Understanding the ignition and explosion of hydrogen induced by a hot particle is crucial for the safety of hydrogen storage, transmission and utilization. In this paper, the ignition/explosion of hydrogen/air mixtures induced by a hot particle is investigated theoretically and numerically. Eigenvalue analysis is conducted for the radical-runaway ignition process in which a detailed reaction mechanism is considered. The governing equation for radical accumulation is converted into a rate-controlling ordinary differential equation (ODE). The ODE can be solved with the help of a hypothetical single-step reaction model, whose kinetic characteristics are related to the positive eigenvalue of the rate matrix constituted by relevant linear chain reactions. Based on the single-step reaction model, the critical ignition Damköhler number can be determined. Besides, transient simulations are conducted using in-house code A-SURF, in which detailed chemistry and transport are considered. The critical ignition temperatures predicted by eigenvalue analysis agree well with experimental data reported in the literature and present numerical results over a wide range of particle radii. The particle surface introduces temperature inhomogeneity in the ignition of a hydrogen/air mixture, which yields a Z-shaped curve of the explosion limit. The Z-shaped curve shifts to a higher temperature and pressure regime along the boundary of the second explosion limit when the particle size decreases. The increasing difficulty in the ignition can be attributed to the strengthening of radical diffusion as the particle becomes smaller. Compared to a homogeneous ignition system, the presence of a particle surface can alter the relative impacts among key chain reactions. The effects of preferential diffusion between heat and mass transport (i.e., Lewis number effect) and equivalence ratio on the Z-shaped curve of the explosion limit are assessed and interpreted. The present study provides useful insights into the kinetics and transport involved in the ignition of hydrogen/air mixtures by a hot particle, which is closely related to the fire/explosion safety of hydrogen.

Clarireedia hainanense: A New Species Is Associated with Dollar Spot of Turfgrass in Hainan, China.

The genus Clarireedia contains multiple species causing dollar spot (DS) on turfgrass worldwide. In November 2020, 119 Clarireedia isolates were obtained from symptomatic seashore paspalum at golf courses in Hainan province and identified to species level based on partial sequence of the internal transcribed spacer (ITS) region. A total of 45 and 22 isolates were identified as C. paspali and C. monteithiana, respectively; the remaining 52 isolates defined a new clade. Isolates from this clade were further selected for phylogenetic, morphological, and biological analyses. Maximum likelihood and Bayesian methods were implemented to obtain phylogenetic trees for partial sequences of the ITS, EF-1α, and McM7 genes. The selected isolates consistently fell into a distinct, well-supported clade within Clarireedia. Morphological and biological characteristics were observed among the different species in Clarireedia. Altogether, this study described a new species, Clarireedia hainanense, which has widespread distribution in Hainan, China. These findings may have important implications for the management of DS disease.

Relationship between the Phenylpropanoid Pathway and Dwarfism of Paspalum seashore Based on RNA-Seq and iTRAQ.

Seashore paspalum is a major warm-season turfgrass requiring frequent mowing. The use of dwarf cultivars with slow growth is a promising method to decrease mowing frequency. The present study was conducted to provide an in-depth understanding of the molecular mechanism of T51 dwarfing in the phenylpropane pathway and to screen the key genes related to dwarfing. For this purpose, we obtained transcriptomic information based on RNA-Seq and proteomic information based on iTRAQ for the dwarf mutant T51 of seashore paspalum. The combined results of transcriptomic and proteomic analysis were used to identify the differential expression pattern of genes at the translational and transcriptional levels. A total of 8311 DEGs were detected at the transcription level, of which 2540 were upregulated and 5771 were downregulated. Based on the transcripts, 2910 proteins were identified using iTRAQ, of which 392 (155 upregulated and 237 downregulated) were DEPs. The phenylpropane pathway was found to be significantly enriched at both the transcriptional and translational levels. Combined with the decrease in lignin content and the increase in flavonoid content in T51, we found that the dwarf phenotype of T51 is closely related to the abnormal synthesis of lignin and flavonoids in the phenylpropane pathway. CCR and HCT may be the key genes for T51 dwarf. This study provides the basis for further study on the dwarfing mechanism of seashore paspalum. The screening of key genes lays a foundation for further studies on the molecular mechanism of seashore paspalum dwarfing.

Study on the differences of gene expression between pear and apple wild cultivation materials based on RNA-seq technique.

BACKGROUND: Pears and apples are both perennial deciduous trees of the Rosaceae family, and both are important economic fruit trees worldwide. The emergence of many varieties in the market has been mostly domesticated from wild to cultivated and regulated by the differential expression of genes. However, the molecular process and pathways underlying this phenomenon remain unclear. Four typical wild and cultivar pear and apple trees at three developmental stages were used in our study to investigate the molecular process at the transcriptome level. RESULT: Physiological observations indicated the obvious differences of size, weight, sugar acid content and peel color in wild and cultivar fruit among each developmental stage. Using next-generation sequencing based RNA-seq expression profiling technology, we produced a transcriptome in procession of a large fraction of annotated pear and apple genes, and provided a molecular basis underlying the phenomenon of wild and cultivar fruit tree differences. 5921 and 5744 differential expression genes were identified in pear and apple at three developmental stages respectively. We performed temporal and spatial differential gene expression profiling in developing fruits. Several key pathways such as signal transduction, photosynthesis, translation and many metabolisms were identified as involved in the differentiation of wild and cultivar fruits. CONCLUSION: In this study, we reported on the next-generation sequencing study of the temporal and spatial mRNA expression profiling of pear and apple fruit trees. Also, we demonstrated that the integrated analysis of pear and apple transcriptome, which strongly revealed the consistent process of domestication in Rosaceae fruit trees. The results will be great influence to the improvement of cultivar species and the utilization of wild resources.

Network analysis reveals the co-expression of sugar and aroma genes in the Chinese white pear (Pyrus bretschneideri).

The quality of pear and other fruit affects their economic value by determining their attractiveness to the consumer. For this reason the two most important quality traits, namely the sugar content and the aroma, have been the focus of much research. This research has been conducted both on the biochemical characteristics of sugar and aroma of fruits and on the activity of enzymes related to their metabolism. In this study, by analyzing the transcriptome of pear fruit, we built the first co-expression network of the genes related to sugar metabolism and those related to aroma, to reveal their connections. Genes that encode beta-glucosidases and sorbitol dehydrogenases are shown to be the hub genes within this network. This study has demonstrated the power of such network analysis for the first time in a non-model organism. Our research can lead to new discoveries that go beyond the previous focus on individual genes.