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Oyster mushroom spherical virus (OMSV) is a mycovirus that inhibits mycelial growth, induces malformation symptoms, and decreases the yield of fruiting bodies in Pleurotus ostreatus. However, the pathogenic mechanism of OMSV infection in P. ostreatus is poorly understood. In this study, RNA sequencing (RNA-seq) was conducted, identifying 354 differentially expressed genes (DEGs) in the mycelium of P. ostreatus during OMSV infection. Verifying the RNA-seq data through quantitative real-time polymerase chain reaction on 15 DEGs confirmed the consistency of gene expression trends. Both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses highlighted the pivotal role of primary metabolic pathways in OMSV infection. Additionally, significant changes were noted in the gene expression levels of carbohydrate-active enzymes (CAZymes), which are crucial for providing the carbohydrates needed for fungal growth, development, and reproduction by degrading renewable lignocellulose. The activities of carboxymethyl cellulase, laccase, and amylase decreased, whereas chitinase activity increased, suggesting a potential mechanism by which OMSV influenced mycelial growth through modulating CAZyme activities. Therefore, this study provided insights into the pathogenic mechanisms triggered by OMSV in P. ostreatus. [ABSTRACT FROM AUTHOR]

Plague is a highly virulent fleaborne zoonotic disease caused by the bacterium Yersinia pestis (1,2). Humans can acquire plague through contact with infectious animal tissues or through inhalation. Human contact [...]

Mycoviruses are usually transmitted horizontally via hyphal anastomosis and vertically through sporulation in natural settings. Oyster mushroom spherical virus (OMSV) is a mycovirus that infects Pleurotus ostreatus, with horizontal transmission via hyphal anastomosis. However, whether OMSV can be vertically transmitted is unclear. This study aimed to investigate the transmission characteristics of OMSV to progeny via basidiospores and horizontally to a new host. A total of 37 single-basidiospore offspring were obtained from OMSV-infected P. ostreatus and Pleurotus pulmonarius for Western blot detection of OMSV. The OMSV-carrying rate among monokaryotic isolates was 19% in P. ostreatus and 44% in P. pulmonarius. Then, OMSV-free and OMSV-infected monokaryotic isolates were selected for hybridization with harvested dikaryotic progeny strains. Western blot analyses of the offspring revealed that the OMSV transmission efficiency was 50% in P. ostreatus and 75% in P. pulmonarius, indicating vertical transmission via sexual basidiospores. Furthermore, we observed the horizontal transfer of OMSV from P. pulmonarius to Pleurotus floridanus. OMSV infection in P. floridanus resulted in significant inhibition of mycelial growth and yield loss. This study was novel in reporting the vertical transmission of OMSV through basidiospores, and its infection and pathogenicity in a new host P. floridanus. [ABSTRACT FROM AUTHOR]

The study investigated the adsorption of dissolved organic carbon (DOC) on Chinese soils from four long-term experiments involving five treatments: (1) no fertilization (control), (2–4) inorganic nitrogen (N), phosphorus (P), and potassium (K) fertilization (N, NP, and NPK), (5) NPK plus manure (NPKM). The results showed that DOC adsorption followed a modified Langmuir isotherm model effectively (R2 = 0.912 ~ 0.991). The maximum adsorption capacity (Qmax) (i.e. saturation deficits) generally increased with increasing soil organic carbon (SOC) due to fertilization in Luvic Phaeozem, Haplic Gypsisols, and Eutric Cambisols. However, it decreased significantly in acidic soils (Haplic Acrisols) from 15.59 g/kg for control, to 13.96, 13.03, 9.30 and 8.02 g/kg for N, NP, NPK and NPKM, respectively. Moreover, long-term fertilization, particularly with organic fertilization (e.g. NPKM), resulted in an increase of carbon (C) saturation by 1.42 g/kg (5.52%) in Luvic Phaeozem, 9.27 g/kg (44.29%) in Haplic Gypsisols, and 3.75 g/kg (27.66%) in Eutric Cambisols; however, there was a slight decrease by 1.70 g/kg (−7.49%) in Haplic Acrisols. Canonical correlation analysis (CCA) revealed that clay content and soil available iron (AFe) might be the crucial factors controlling C deficits, and subsequently, C saturation, along with current SOC. In conclusion, long-term fertilization contributed to C saturation in neutral-to-alkaline soils, but not in acidic soils. Thus, further attention should be paid to the long-term effects of fertilization on C saturation. [ABSTRACT FROM AUTHOR]

In plants, iron (Fe) regulated transporters (IRT) play important roles in uptake and transport of Fe that contributes to plant growth and development. However, biological functions of IRT transporters in fruit trees are still unknown. This study isolated 10 VvIRT genes from ‘Marselan’ grape, with varying expression levels across different tissues/organs, particularly enhanced under Fe depletion, especially in roots. Notably, VvIRT7 is the most abundantly expressed IRT gene in grape, beneficially restoring the Fe2+ uptake defect of yeast mutant DEY1453. Furthermore, VvIRT7 showed dominant expression in the roots of irt1/35S::IRT7 complementation lines. Overexpressing of VvIRT7 rescued the retarded growth of irt1 knockout mutant, by increasing the fresh weight, dry weight, total root length, total root surface, lateral root numbers, total leaf chlorophyll, ACO activity, NiR activity, SDH activity, and tissue Fe concentration. This study provides insights for understanding molecular mechanisms of Fe uptake and transport in grape.Key message: A grape iron regulated transporter gene involved in Fe2+ transport and resistance to Fe2+ deficiency was isolated, heterologously expressed, and functionally characterized. [ABSTRACT FROM AUTHOR]

The cultivation of strawberries in controlled environments presents challenges related to environmental stressors, especially insufficient light. Melatonin, as a widely investigated plant growth regulator, was considered as a potential candidate to mitigate damage, and enhance photosynthesis stability. However, whether melatonin can improve photosynthesis under light deficiency in woodland strawberry (Fragaria vesca) remains elusive. In this study, we evaluated gas exchange parameters, Chlorophyll fluorescence parameters, photochemical efficiency, and the related genes' expression levels to decipher the multifaceted impact of melatonin on photosynthesis. We found concentration-dependent effects of melatonin on photosynthetic parameters, with potential benefits at lower concentration and inhibitory effects at higher concentration. Notably, melatonin increased non-photochemical quenching (NPQ), a mechanism for dissipating excess light energy, while leaving photochemical quenching (qP) relatively stable. Further analysis showed that melatonin up-regulated key xanthophyll cycle-related genes (DHAR, VDE, and PsbS), indicating its involvement in energy dissipation processes. In conclusion, our study uncovered the dual and complex role of melatonin in the short-term response of photosynthesis in woodland strawberries under low-light conditions. [ABSTRACT FROM AUTHOR]

In plants, ferritin proteins play an important role in iron (Fe) storage which contributes to plant growth and development. However, the biological functions of ferritins in fruit trees are essentially unknown. In this study, three Ferritin genes were isolated from 'Zhentong No. 3' peach, which were named PpFer1-PpFer3. The expression levels of these genes were different in distinct tissues/organs. Notably, PpFer1 was the most abundantly expressed Ferritin family gene in all tested tissues of 'Zhentong No. 3' peach; its expression levels were significantly enhanced throughout the entire peach seedling under Fe toxicity and H2O2 stress, particularly in the leaves. In addition, over-expression of PpFer1 was effective in rescuing the retarded growth of Arabidopsis fer1-2 knockout mutant, embodied in enhanced fresh weight, primary root length, lateral root numbers, total root length, total leaf chlorophyll, stomatal conductance (Gs), net photosynthetic rate (Pn), transpiration rate, and tissue Fe concentration. This study provides insights into understanding the molecular mechanisms of Fe storage and sequestration in perennial fruit trees. [ABSTRACT FROM AUTHOR]

To elucidate the effects of exogenous salicylic acid (SA) treatment on the cold resistance of peach flower, the floral organs of two peach cultivars were treated with 20 mg/L SA and stored at 0°C for observation and sample collection. Water application was the control. After a treatment period, the anther relative water content of the control and SA-treated flowers decreased. The extent of the reduction was greater in the control, suggesting that the SA treatment significantly helped to maintain the anther water content of peach. Analysis of the stigma relative electric conductivity revealed that the SA treatment prevented membrane injury during the low temperature treatment. Additionally, we measured CBF gene expression at low temperature in the petal, stigma and ovary. The expression was markedly upregulated in the cold-treated floral organs. CBF gene expression after SA treatment was higher than in the control when cold conditions continued. These results suggest that the effects of SA on ameliorating the freezing injury to peach floral organs and on enhancing cold tolerance may be associated with the induction of CBF gene.

Low‐temperature storage is a widely used method for peach fruit storage. However, the impact of PpCBFs on pectin degradation during low‐temperature storage is unclear. As such, in this study, we stored the melting‐flesh peach cultivar "Fuli" at low temperature (LT, 6°C) and room temperature (RT, 25°C) to determine the effect of different temperatures on its physiological and biochemical changes. Low‐temperature storage can inhibit the softening of "Fuli" peaches by maintaining the stability of the cell wall. It was found that the contents of water‐soluble pectin and ionic‐soluble pectin in peach fruit stored at RT were higher than those stored at LT. The enzyme activities of polygalacturonase (PG), pectate lyase (PL), and pectin methylesterase (PME) were all inhibited by LT. The expressions of PpPME3, PpPL2, and PpPG were closely related to fruit firmness, but PpCBF2 and PpCBF3 showed higher expression levels at LT than RT. The promoters of PpPL2 and PpPG contain the DER motif, which suggested that PpCBF2 and PpCBF3 might negatively regulate their expression by directly binding to their promoters. These results indicated that LT may maintain firmness by activating PpCBFs to repress pectin‐degradation‐related enzyme genes during storage. [ABSTRACT FROM AUTHOR]

Background: Following its resurgence in 1982, rodent plague has been linked to a wide range of circulation risks in Yunnan Province. The most serious public health concern associated with effective plague control is determining how various ecological variables influence the differential risk of transmission. Methods: We investigated the population dynamics of the hosts and vectors using large-scale epidemiological surveillance data. In a seasonal eco-epidemiological model, we evaluated the impact of ecological conditions on the vectored flea index (VFI) to determine the rate of plague transmission. Results: The findings revealed a changing species composition in natural foci over time. Additionally, shifting distributional ranges of species by elevation may be vital in modulating the VFI. The model estimates indicate that the dynamic VFI contributes to spatiotemporal variance in transmission. Conclusions: The VFI could be a critical ecological indicator, allowing for real-time tracking and prompt intervention in the circulation of rodent plague. Understanding eco-epidemiological diversity can provide essential insights into effective responses to future plague resurgence. Author summary: Plague have resurged among rodents in Yunnan Province since 1982, and intermittently occurs among humans. Yet the local risk of rodent plague dynamics has been highly diverse across ecological contexts. In natural foci, suggestions for this ecological diversity include high species richness and cyclic transmission between hosts and vectors. Here, we developed an eco-epidemiological framework to position the epidemiological dynamics of rodent plague in local ecological contexts. Our results suggest that diverse ecological conditions may have shaped the local risk of plague transmission in Yunnan Province. Typically, incremental of elevation has been associated with the tradeoff between the increased diversity and averted fraction of main host and vector species. More importantly, vectored flea index could be a critical ecological indicator for plague management. [ABSTRACT FROM AUTHOR]

Bartonella species has been validated as blood-borne bacteria in mammals and has a substantial opportunity to be harbored by a variety of hematophagous arthropod vectors. Bats, along with their ectoparasites, are recognized worldwide as one of the natural reservoir hosts for these bacteria. However, there have been few investigations of Bartonella bacteria toward a broad range of obligated bat ectoparasites in China. Here, molecular detection of Bartonella species was performed to survey the infection among bat ectoparasites and follow-up phylogenetic analyses to further characterize the evolutionary relationships of the genus. A total of 434 bat ectoparasites involving four types of arthropods, namely, bat mites, bat tick, bat fleas, and bat flies (further divided into traditionally fly-like bat flies and wingless bat flies) were collected in 10 trapping sites in Yunnan Province, southwestern China. Bartonella was detected by PCR amplification and sequencing through four gene target fragments (gltA, ftsZ, rpoB, and ITS). Accordingly, diverse Bartonella species were discovered, including both the validated species and the novel genotypes, which were characterized into several geographical regions with high prevalence. Phylogenetic analyses based on gltA and multi-locus concatenated sequences both demonstrated strong phylogeny–trait associations of Bartonella species from bats and their parasitic arthropods, suggesting the occurrence of host switches and emphasizing the potential connecting vector role of these ectoparasites. Nevertheless, the maintenance and transmission of Bartonella in both bat and hemoparasite populations have not been fully understood, as well as the risk of spillage to humans, which warrants in-depth experimental studies focusing on these mammals and their ectoparasites. [ABSTRACT FROM AUTHOR]