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Verticillium dahliae is a broad host-range pathogen that causes vascular wilt in plants. The Verticillium wilt disease severity assay on plants caused by V. dahliae mainly includes two methods, one is a plant disease grade classification based on disease severity statistics [namely the disease index (DI)], and the other is the V. dahliae biomass quantification in plants (namely the fungal biomass). In this study, the relationships of pathogenicity with the DI, pathogenicity with the biomass, and the correlation analysis of the DI and relative fungal biomass were analysed. The results showed that pathogenicity assessment of V. dahliae strains using the DI method was able to give an intuitive reflection of the pathogenic ability for defoliating and non-defoliating strains; moreover, the method of quantitative PCR for fungal biomass also had high repeatability and stability. As a whole, the correlation coefficient between the DI and fungal biomass values of 28 strains was 0.728, indicating that the two data sets were highly correlated; however, the correlation coefficients of the defoliating strains and non-defoliating strains were only 0.5384 and 0.4547, respectively. In conclusion, the correlation coefficient between the DI and the fungal biomass presented high consistency, which could provide some meaningful exploration for the more accurate pathogenicity identification of V. dahliae. [ABSTRACT FROM AUTHOR]

Knowledge about the seismic elastic modulus dispersion, and associated attenuation, in fluid-saturated rocks is essential for better interpretation of seismic observations taken as part of hydrocarbon identification and time-lapse seismic surveillance of both conventional and unconventional reservoir and overburden performances. A Seismic Elastic Moduli Module has been developed, based on the forcedoscillations method, to experimentally investigate the frequency dependence of Young's modulus and Poisson's ratio, as well as the inferred attenuation, of cylindrical samples under different confining pressure conditions. Calibration with three standard samples showed that the measured elastic moduli were consistent with the published data, indicating that the new apparatus can operate reliably over a wide frequency range of f=[1-2000, 106] Hz. The Young's modulus and Poisson's ratio of the shale and the tight sandstone samples were measured under axial stress oscillations to assess the frequency- and pressure-dependent effects. Under dry condition, both samples appear to be nearly frequency independent, with weak pressure dependence for the shale and significant pressure dependence for the sandstone. In particular, it was found that the tight sandstone with complex pore microstructure exhibited apparent dispersion and attenuation under brine or glycerin saturation conditions, the levels of which were strongly influenced by the increased effective pressure. In addition, the measured Young's moduli results were compared with the theoretical predictions from a scaled poroelastic model with a reasonably good agreement, revealing that the combined fluid flow mechanisms at both mesoscopic and microscopic scales possibly responsible for the measured dispersion. [ABSTRACT FROM AUTHOR]

Chemical fungicides can cause drug resistance of plant pathogenic fungi, environmental pollution, and potential threats to humans and animals. Therefore, developing low-toxicity, high-efficient and environment-friendly biological control products is critical for green prevention, controlling plant fungal diseases, and maintaining ecological balance. Biocontrol research mainly includes the following aspects: antagonistic microorganisms, fungicidal proteins, RNA interference techniques and botanical fungicides. Significantly, natural products extracted from medicinal plants are valuable repertoire for inhibiting plant fungal diseases. This review systematically reviewed the research advances of using natural products from medicinal plants to inhibit plant pathogenic fungi, including the types of natural products, extraction methods, and antifungal mechanisms. The further prospects for the study and application, which provide the reference for botanical fungicide development and practical application in preventing and controlling plant fungal disease, were also discussed. [ABSTRACT FROM AUTHOR]

To establish a safe, efficient, and simple biocontrol measure for gray mold disease caused by Botrytis cinerea, the basic characteristics and antifungal activity of KRS005 were studied from multiple aspects including morphological observation, multilocus sequence analysis and typing (MLSA-MLST), physicalbiochemical assays, broad-spectrum inhibitory activities, control efficiency of gray mold, and determination of plant immunity. The strain KRS005, identified as Bacillus amyloliquefaciens, demonstrated broad-spectrum inhibitory activities against various pathogenic fungi by dual confrontation culture assays, of which the inhibition rate of B. cinerea was up to 90.3%. Notably, through the evaluation of control efficiency, it was found that KRS005 fermentation broth could effectively control the occurrence of tobacco leaves gray mold by determining the lesion diameter and biomass of B. cinerea on tobacco leaves still had a high control effect after dilution of 100 folds. Meanwhile, KRS005 fermentation broth had no impact on the mesophyll tissue of tobacco leaves. Further studies showed that plant defense-related genes involved in reactive oxygen species (ROS), salicylic acid (SA), and jasmonic acid (JA)-related signal pathways were significantly upregulated when tobacco leaves were sprayed with KRS005 cellfree supernatant. In addition, KRS005 could inhibit cell membrane damage and increase the permeability of B. cinerea. Overall, KRS005, as a promising biocontrol agent, would likely serve as an alternative to chemical fungicides to control gray mold. [ABSTRACT FROM AUTHOR]

Understanding how plant pathogenic fungi adapt to their hosts is of critical importance to securing optimal crop productivity. In response to pathogenic attack, plants produce reactive oxygen species (ROS) as part of a multipronged defense response. Pathogens, in turn, have evolved ROS scavenging mechanisms to undermine host defense. Thioredoxins (Trx) are highly conserved oxidoreductase enzymes with a dithiol-disulfide active site, and function as antioxidants to protect cells against free radicals, such as ROS. However, the roles of thioredoxins in Verticillium dahliae, an important vascular pathogen, are not clear. Through proteomics analyses, we identified a putative thioredoxin (VdTrx1) lacking a signal peptide. VdTrx1 was present in the exoproteome of V. dahliae cultured in the presence of host tissues, a finding that suggested that it plays a role in host-pathogen interactions. We constructed a VdTrx1 deletion mutant ΔVdTrx1 that exhibited significantly higher sensitivity to ROS stress, H2O2, and tert-butyl hydroperoxide (t-BOOH). In vivo assays by live-cell imaging and in vitro assays by western blotting revealed that while VdTrx1 lacking the signal peptide can be localized within V. dahliae cells, VdTrx1 can also be secreted unconventionally depending on VdVps36, a member of the ESCRT-II protein complex. The ΔVdTrx1 strain was unable to scavenge host-generated extracellular ROS fully during host invasion. Deletion of VdTrx1 resulted in higher intracellular ROS levels of V. dahliae mycelium, displayed impaired conidial production, and showed significantly reduced virulence on Gossypium hirsutum, and model plants, Arabidopsis thaliana and Nicotiana benthamiana. Thus, we conclude that VdTrx1 acts as a virulence factor in V. dahliae. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to investigate the influence of advanced maternal age on the maternal and neonatal outcomes of preterm pregnancies. Material and methods: The characteristics of patients admitted to the Department of Obstetrics and Gynecology, The First Affiliated Hospital of Fujian Medical University between January 2015 and March, 2019 were retrospectively reviewed. The maternal and neonatal outcomes were compared between advanced maternal age group (≥ 35 years) and younger age group (18-34 years). Statistical analysis was performed by applying the SPSS software. Results: The study population consisted of 986 pregnancies with preterm delivery and 1094 liveborn preterm infants. Multivariate analyses demonstrated that mothers of advanced age were more likely to suffer iatrogenic preterm birth, placenta previa, preeclampsia, gestational diabetes mellitus and postpartum hemorrhage, but less likely to suffer multiple gestation. In terms of neonatal outcomes, advanced maternal age was associated with a decreased rate of low birthweight in an adjusted model without multiple gestation. However, with multiple gestation included in the adjusted model, advanced maternal age was only associated with an increased rate of hyperbilirubinemia. Conclusions: Advanced maternal age was a risk factor for adverse pregnancy outcomes including iatrogenic preterm birth, placenta previa, preeclampsia, gestational diabetes mellitus, postpartum hemorrhage, and a protective factor for multiple gestation. Regarding neonatal outcomes, advanced maternal age was related to a decreased rate of low birthweight or an increased rate of hyperbilirubinemia depending on the adjustment for multiple gestation. [ABSTRACT FROM AUTHOR]

Verticillium wilt, caused by the Verticillium dahliae phytopathogen, is a devastating disease affecting many economically important crops. Previous studies have shown that the exoproteome of V. dahliae plays a significant role in this pathogenic process, but the components and mechanisms that underlie this remain unclear. In this study, the exoproteome of V. dahliae was induced in a cotton-containing C'zapek-Dox (CCD) medium and quantified using the high-throughput isobaric tag technique for relative and absolute quantification (iTRAQ). Results showed that the abundance of 271 secreted proteins was affected by the CCD medium, of which 172 contain typical signal peptides generally produced by the Golgi/endoplasmic reticulum (ER). These enhanced abundance proteins were predominantly enriched in carbohydrate hydrolases; 126 were classified as carbohydrate-active (CAZymes) and almost all were significantly up-regulated in the CCD medium. Results showed that CAZymes proteins 30 and 22 participate in pectin and cellulose degradation pathways, corresponding with the transcription levels of several genes encoded plant cell wall degradation enzyme activated significantly during cotton infection. In addition, targeted deletion of two pectin lyase genes (VdPL3.1 and VdPL3.3) impaired wilt virulence to cotton. This study demonstrates that the V. dahliae exoproteome plays a crucial role in the development of symptoms of wilting and necrosis, predominantly via the pathogenic mechanisms of plant cell wall degradation as part of host plant infection. [ABSTRACT FROM AUTHOR]

Background: Gossypium raimondii is a Verticillium wilt-resistant cotton species whose genome encodes numerous disease resistance genes that play important roles in the defence against pathogens. However, the characteristics of resistance gene analogues (RGAs) and Verticillium dahliae response loci (VdRLs) have not been investigated on a global scale. In this study, the characteristics of RGA genes were systematically analysed using bioinformatics-driven methods. Moreover, the potential VdRLs involved in the defence response to Verticillium wilt were identified by RNA-seq and correlations with known resistance QTLs. Results: The G. raimondii genome encodes 1004 RGA genes, and most of these genes cluster in homology groups based on high levels of similarity. Interestingly, nearly half of the RGA genes occurred in 26 RGA-gene-rich clusters (Rgrcs). The homology analysis showed that sequence exchanges and tandem duplications frequently occurred within Rgrcs, and segmental duplications took place among the different Rgrcs. An RNA-seq analysis showed that the RGA genes play roles in cotton defence responses, forming 26 VdRLs inside in the Rgrcs after being inoculated with V. dahliae. A correlation analysis found that 12 VdRLs were adjacent to the known Verticillium wilt resistance QTLs, and that 5 were rich in NB-ARC domain-containing disease resistance genes. Conclusions: The cotton genome contains numerous RGA genes, and nearly half of them are located in clusters, which evolved by sequence exchanges, tandem duplications and segmental duplications. In the Rgrcs, 26 loci were induced by the V. dahliae inoculation, and 12 are in the vicinity of known Verticillium wilt resistance QTLs. [ABSTRACT FROM AUTHOR]

Background: Gossypium raimondii is a Verticillium wilt-resistant cotton species whose genome encodes numerous disease resistance genes that play important roles in the defence against pathogens. However, the characteristics of resistance gene analogues (RGAs) and Verticillium dahliae response loci (VdRLs) have not been investigated on a global scale. In this study, the characteristics of RGA genes were systematically analysed using bioinformatics-driven methods. Moreover, the potential VdRLs involved in the defence response to Verticillium wilt were identified by RNA-seq and correlations with known resistance QTLs. Results: The G. raimondii genome encodes 1004 RGA genes, and most of these genes cluster in homology groups based on high levels of similarity. Interestingly, nearly half of the RGA genes occurred in 26 RGA-gene-rich clusters (Rgrcs). The homology analysis showed that sequence exchanges and tandem duplications frequently occurred within Rgrcs, and segmental duplications took place among the different Rgrcs. An RNA-seq analysis showed that the RGA genes play roles in cotton defence responses, forming 26 VdRLs inside in the Rgrcs after being inoculated with V. dahliae. A correlation analysis found that 12 VdRLs were adjacent to the known Verticillium wilt resistance QTLs, and that 5 were rich in NB-ARC domain-containing disease resistance genes. Conclusions: The cotton genome contains numerous RGA genes, and nearly half of them are located in clusters, which evolved by sequence exchanges, tandem duplications and segmental duplications. In the Rgrcs, 26 loci were induced by the V. dahliae inoculation, and 12 are in the vicinity of known Verticillium wilt resistance QTLs. [ABSTRACT FROM AUTHOR]

The major latex protein (MLP) gene in Gossypium hirsutum was cloned and designated Gh-MLP. Expression in cotton root was induced by salt stress and Verticillium dahliae toxin, and bioinformatic analysis showed that Gh-MLP encodes a 157-amino acid protein that is similar to members of the MLP subfamily in the Bet v 1 family. Although the structure of MLP is similar to Bet v 1 family proteins, the sequence identity to other subfamilies of Bet v 1 proteins is less than 20%. The Gh-MLP promoter contains potential cis-acting elements for response to salt stress and fungal elicitor. RT-PCR analysis showed that Gh-MLP expression was rapidly induced by NaCl and V. dahliae toxin, and induction was maintained over 72 h. However, Gh-MLP transgenic Arabidopsis thaliana did not show resistance to V. dahiae, salt tolerance was significantly enhanced. In contrast to the wild type, the Gh-MLP transgene allowed plants to germinate normally after treatment with 75 mM NaCl. Total flavonoid was twofold higher in transgenic Arabidopsis than in the control, suggesting that Gh-MLP might be involved in altering flavonoid content. We hypothesize Gh-MLP, like other Bet v 1 family proteins, participates in the binding or transport of ligands through its specific three-dimensional structure, and takes part in defensive responses to biotic and abiotic stresses. [ABSTRACT FROM AUTHOR]