The weathering of ancient glass relics has long been a concerned. Therefore, a systematic and more comprehensive mathematical model with which to correctly judge the category of ancient glass ...products whose chemical composition changes due to weathering should be established. This paper systematically analyzes and studies the changes in the composition of ancient glass products as a result of weathering of. We first analyze the surface weathering of glass relics and its correlation with three properties and establish a multivariable time-series model to predict the chemical-composition content before weathering. Next, we use one-way analysis of variance for subclassification and, finally, we use a principal component analysis of the rationality, and change the significance level to determine its sensitivity, for the reasonable prediction of the chemical-composition content and classification to provide a theoretical basis for improving the model. This allows the model to provide reference values, which can be used in the protection of cultural relics, historical research, and other fields.
•This study analyzed how PAs were involved in AMF-enhanced drought tolerance of plants.•AM trifoliate orange had higher Put and Cad and lower Spd and Spm under drought.•Mycorrhizal plants had higher ...activity of PA catabolic enzymes and Put synthetase.•AM plants showed overexpression of PtSPMS, PtPAO, PtSOD, and PtCAT1 under DS.•AM plants represented down-regulated expression of PtCuAO under DS.
Arbuscular mycorrhizas enhance the drought tolerance of host plants through several underlying mechanisms. Polyamines (PAs) are known to protect plant cells from the damages of drought by enhancing the antioxidant defense system, restricting ethylene synthesis, maintaining cell pH and ion homeostasis, preventing chlorophyll loss, and so on; concomitantly, the mechanism through which arbuscular mycorrhizal (AM) fungi modulate PA metabolism to enhance drought tolerance of plants remains unclear. A pot experiment was conducted to assess how an AM fungus, Funneliformis mosseae, affects root PA homeostasis, activities and gene expressions of PA-related synthesizing and degrading enzymes, hydrogen peroxide (H2O2, a PA metabolite) production, and antioxidant enzyme gene expressions in trifoliate orange (Poncirus trifoliata) exposed to drought stress (DS). AM seedlings showed higher growth traits, leaf water potential, two plasma membrane intrinsic protein aquaporin gene expressions, and chlorophyll concentrations than non-AM seedlings under well-watered (WW) and DS conditions. Mycorrhizal treatment induced higher putrescine and cadaverine but lower spermidine and spermine concentrations, with higher activity of PA catabolic enzymes (copper-containing diamine oxidase, CuAO; polyamine oxidase, PAO) and putrescine synthases (ornithine decarboxylaseby; arginine decarboxylase, ADC). Mycorrhizas up-regulated the expression of the spermine synthase gene, PtSPMS, under DS, and down-regulated the transcript levels of PA catabolic enzyme genes (PtCuAO1, PtCuAO2, PtCuAO6, and PtCuAO8) and PA synthase genes (PtADC1 and PtADC2) under DS. PtPAO1, PtPAO2, and PtPAO3 had higher expression levels in AMF-inoculated seedlings, as compared to non-AMF-inoculated seedlings, under DS, triggering reactive oxygen species-related signalling for stress responsiveness through low H2O2 levels by up-regulating the expression of PtMn-SOD, PtCu/Zn-SOD, and PtCAT1. This study demonstrated that mycorrhizas have the capacity to modulate PA metabolism to enhance the drought tolerance of plants.
This study examined parent-child interactions during foreign-language shared reading of Anglophone picturebooks at home by Chinese parents. It is among the first to probe foreign-language shared ...reading in the home setting. Data was obtained from in-depth ethnographic observation of seven parent-child dyads and from interviews, with a survey comprising 565 parent respondents providing background for this wider evidence. A grounded theory approach was applied to generate a new, five-part typology of Chinese parents' English picturebook reading practices. This new typology reveals the diversity of parent-child interaction processes by categorizing them according to five foci: the literal focus, the literacy skill focus, the literary focus, the exploratory focus and the digital focus. The findings of this study may have a reciprocal effect on the study of first- and second-language shared reading practices and can be applied to analysis of or intervention in shared reading, at home or in school settings.
In the peripheral nervous system, Schwann cells are the primary type of glia; their in vitro differentiation and dedifferentiation system has not been described in detail in the literature. Thus, an ...in vitro differentiation and dedifferentiation system of rat Schwann cells is described in this protocol. These cultures and systems may be used to investigate the morphological and biochemical effects of drug interventions or lentivirus-mediated gene transfer on Schwann cells during differentiation or dedifferentiation. Graphical abstract.
•Molecular mechanisms of AM fungi-enhanced plant drought tolerance are reviewed.•Functional (e.g., AQPs, PTs and LEA) and regulatory (e.g., 14–3-3 protein) genes are modulated by AM fungi under ...drought.•Transcription factors including GRAS, MYB and AP2/ERF are regulated by AM fungi to trigger hormone signaling.
Soil drought, an important abiotic stress, seriously inhibits plant growth and physiological activities. However, arbuscular mycorrhizal (AM) fungi in soil can enhance plant adaptability and tolerance to drought stress after establishing mycorrhizal symbiosis with plant roots. Studies on AM fungi-enhanced host drought tolerance are involved in physiological, morphological and molecular levels, with a focus on physiological mechanisms. Study on the molecular mechanisms explaining how arbuscular mycorrhizae enhance plant drought tolerance has being lagging behind that on the physilogical mechanisms, however, increasingly accumulated experiments have focused on the molecular mechanisms during the past decade. This review addresses the question of which functional and regulatory genes in host plants are involved in AM fungi-modulated drought tolerance of host plants, and highlights how these genes play the role in physiological activities such as osmoregulation, water and nutrient transport, hormones, and signal transduction under mycorrhization. The review also outlines how mycorrhizal plants modulate plant drought tolerance through the regulation of transcription factors (GRAS, MYB and AP2/ERF), and prospects an outlook for future research in exploring the interaction of signal pathways in gene regulation of mycorrhizal plants.
•Mycorrhizal hyphae have the role in water absorption from soil.•Hyphal water absorption rate was 0.126–1.973mg H2O/h/mm in trifoliate orange.•Drought significantly elevated hyphal water absorption ...rate by 2.3–6.6 times.•Hyphal water contribution to host plants is more important under DS than under WW.
Mycorrhizal hyphae have the functioning on water absorption from soil, while the information regarding hyphal water absorption rate is not fully known. In this study, 37-μm nylon meshes were positioned in a pot bottom to allow mycorrhizal extraradical hyphae, but not roots, to pass through the mesh. The whole pot was placed in a beaker, where distilled water was supplied, reaching a 0.5-cm air gap between the pot bottom and water surface of the beaker. Citrus rootstock, trifoliate orange (Poncirus trifoliata) seedlings of pots were inoculated with Funneliformis mosseae and Paraglomus occultum and also exposed to well-watered (WW) and drought stress (DS). The 71-days soil DS significantly inhibited root mycorrhizal colonization and hyphal length in soil and mesh, regardless of mycorrhizal fungal species. The hyphal water absorption rate was 0.607–1.973mg H2O/h/mm for F. mosseae and 0.126–0.963mg H2O/h/mm for P. occultum, respectively. The DS treatment significantly elevated hyphal water absorption rate by 2.3–6.6 times. The increase of leaf water potential by mycorrhization was higher under DS than under WW. Our results provide a quantitative estimation of water absorption rate by mycorrhizal extraradical hyphae and also suggest more important water contribution of hyphae to the host plant under DS than under WW.
