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Field-effect-transistor (FET)-type gas sensors have attracted a surge of research interest due to their low power dissipation and exceptional sensitivity. However, theoretical explorations into their sensing capability and underlying mechanism remain scarce. Herein, taking the pure and defective WTe2 monolayers as the sensing platforms, we systematically investigate the sensing characteristics and working principles of FET-type gas sensors in response to various hazardous gases, including SO2, CO, NO, NH3, and NO2, using first-principles calculations and statistical thermodynamic modeling. Our findings reveal that the pure WTe2-based FET-type gas sensor, operating at zero gate voltage, shows remarkably high sensitivity and reusability for NO2 detection, achieving 96% sensitivity at a low concentration of 20 ppb. Our research demonstrates that the introduction of Te-vacancies serves as a highly efficient strategy for enhancing the sensitivity of the gas sensor towards all tested toxic gases, while ensuring its reusability. Applying a gate voltage to the pure WTe2-based FET-type gas sensor further improves its sensitivity to NO2, surpassing 90% within the whole bias range, and reaching 97% under the gate voltage of 3 V. This improvement is attributed to the upward shift of the conduction bands under a positive gate voltage with respect to the chemical potential of the source, which increases the electron barrier and decreases the conductance. Our research offers a promising approach for achieving ultra-sensitive and recyclable detection of toxic gases at ppb-level concentration. [ABSTRACT FROM AUTHOR]

Summary: Ectomycorrhizal symbiosis, which involves mutually beneficial interactions between soil fungi and tree roots, is essential for promoting tree growth. To establish this symbiotic relationship, fungal symbionts must initiate and sustain mutualistic interactions with host plants while avoiding host defense responses. This study investigated the role of reactive oxygen species (ROS) generated by fungal NADPH oxidase (Nox) in the development of Laccaria bicolor/Populus tremula × alba symbiosis.Our findings revealed that L. bicolor LbNox expression was significantly higher in ectomycorrhizal roots than in free‐living mycelia. RNAi was used to silence LbNox, which resulted in decreased ROS signaling, limited formation of the Hartig net, and a lower mycorrhizal formation rate.Using Y2H library screening, BiFC and Co‐IP, we demonstrated an interaction between the mitogen‐activated protein kinase LbSakA and LbNoxR. LbSakA‐mediated phosphorylation of LbNoxR at T409, T477 and T480 positively modulates LbNox activity, ROS accumulation and upregulation of symbiosis‐related genes involved in dampening host defense reactions.These results demonstrate that regulation of fungal ROS metabolism is critical for maintaining the mutualistic interaction between L. bicolor and P. tremula × alba. Our findings also highlight a novel and complex regulatory mechanism governing the development of symbiosis, involving both transcriptional and posttranslational regulation of gene networks. [ABSTRACT FROM AUTHOR]

Polysaccharides have attracted much attention in the food industry due to their diverse biological activities. To date, research on the mechanism of polysaccharide synthesis has mainly focused on the role of crucial enzymes in the polysaccharide synthesis pathway, but other genes that regulate polysaccharide synthesis have not been well explored. In this study, the GlPP2C1 gene, encoding a phosphoprotein type 2C phosphatase, was cloned, and PP2C-silenced strains (PP2C1i-1 and PP2C1i-3) were screened. Measurements of the polysaccharide content and cell wall tolerance revealed that GlPP2C1 silencing increased the polysaccharide content and enhanced cell wall resistance in Ganoderma lingzhi. The contents of intracellular polysaccharides (IPS), extracellular polysaccharides (EPS) and β-1,3-D-glucan in PP2C-silenced strains were increased by 25%, 33% and 36%, respectively, compared with those in the WT strains and strains transformed with an empty vector. Further mechanistic studies showed that GlPP2C1 silencing increased the content of Ganoderma lingzhi polysaccharides (GL-PS) through Slt2. In summary, this study revealed the mechanism through which protein phosphatase regulates GL-PS biosynthesis for the first time. [ABSTRACT FROM AUTHOR]

The magnetism of highly oriented pyrolytic graphite (HOPG) induced by 70 keV 12C+ ion implantation was investigated by using electron spin resonance (ESR) and theoretical simulations of the electronic structure of defective graphite using spin-polarized density functional theory. The results indicate that defects produced by 12C+ ion implantation can induce magnetic moments which are localized since a L1 line is observed at a fixed resonance field, independent of the angle between the field and the c axis of the HOPG sample. The angle and temperature dependence of the ESR spectra indicates that extrinsic carriers are induced in the implanted layer, and they may have an exchange interaction with local spins to produce a single asymmetric L1 line of the implanted sample. The consistent results given by the ESR spectra and the theoretical simulations of the electronic structure of defective graphite provide a clear explanation for the magnetic order in 12C+ ion-implanted HOPG. The defects produced by the implantation induce local magnetic moments in the sample. Due to the interaction between the local spins and the extrinsic carriers, the local magnetic moments may be coupled through the mediation of itinerant carriers. [ABSTRACT FROM AUTHOR]

We theoretically investigated the electronic structures and magnetic properties of (Mn,C)-codoped ZnO system based on the first-principles calculations within a GGA+Up,d approach. We found that codoping C is a promising approach to enhance the ferromagnetic coupling between the nearest-neighboring Mn ions due to the strong hybridization between the C:2p and the Mn:3d states. Moreover, the spin-polarized states induced by C are so extended that they can mediate long-ranged ferromagnetic exchange interactions beyond the nearest-neighboring case. Therefore, (Mn,C)-codoped ZnO is expected to be a ferromagnetic semiconductor with long-ranged ferromagnetism and high Curie temperature. [ABSTRACT FROM AUTHOR]

Summary: How cells drive the phospholipid signal response to heat stress (HS) to maintain cellular homeostasis is a fundamental issue in biology, but the regulatory mechanism of this fundamental process is unclear. Previous quantitative analyses of lipids showed that phosphatidylinositol (PI) accumulates after HS in Ganoderma lucidum, implying the inositol phospholipid signal may be associated with HS signal transduction. Here, we found that the PI‐4‐kinase and PI‐4‐phosphate‐5‐kinase activities are activated and that their lipid products PI‐4‐phosphate and PI‐4,5‐bisphosphate are increased under HS. Further experimental results showed that the cytosolic Ca2+ ([Ca2+]c) and ganoderic acid (GA) contents induced by HS were decreased when cells were pretreated with Li+, an inhibitor of inositol monophosphatase, and this decrease could be rescued by PI and PI‐4‐phosphate. Furthermore, inhibition of PI‐4‐kinases resulted in a decrease in the Ca2+ and GA contents under HS that could be rescued by PI‐4‐phosphate but not PI. However, the decrease in the Ca2+ and GA contents by silencing of PI‐4‐phosphate‐5‐kinase could not be rescued by PI‐4‐phosphate. Taken together, our study reveals the essential role of the step converting PI to PI‐4‐phosphate and then to PI‐4,5‐bisphosphate in [Ca2+]c signalling and GA biosynthesis under HS. [ABSTRACT FROM AUTHOR]

Ganoderma lucidum, which contains many pharmacologically active compounds, is regarded as a traditional medicinal fungus. Nevertheless, the scarcity of basic research limits the commercial value and utilization of G. lucidum. As a class of highly conserved, phosphopeptide-binding proteins present in all eukaryotes, 14-3-3 proteins play vital roles in controlling multiple physiological processes, including signal transduction, primary metabolism, and stress responses. However, knowledge of the roles of 14-3-3 proteins in Basidiomycetes is sparse. In this article, two homologs of 14-3-3 proteins, encoded by the two distinct genes GlBmh1 and GlBmh2, were distinguished in G. lucidum. We found that GlBmh1 and GlBmh2 were expressed at various developmental stages, including in vegetative mycelium cultivated on solid medium and in primordia and fruiting bodies. Moreover, we constructed GlBmh1 single-silenced strains, GlBmh2 single-silenced strains, and 14-3-3 double-silenced mutants for further study. When GlBmh1 and GlBmh2 were inhibited by RNA interference, the growth rate of mycelia was decreased, and the distance between the aerial hyphal branches was reduced; responses to various abiotic stresses such as oxidants and cell wall and osmotic stressors were also changed. Furthermore, the contents of secondary metabolite ganoderic acids (GAs) were increased after GlBmh1 and GlBmh2 were simultaneously silenced. Taken together, we provide evidence that implicates potential roles for the two 14-3-3 proteins in affecting growth and GA biosynthesis, thereby providing new insights into the basic functions of 14-3-3 proteins in G. lucidum. [ABSTRACT FROM AUTHOR]