Mycorrhizal inoculation stimulates growth, photosynthesis and nutrient uptake in a wide range of host plants. However, the ultimate effects of arbuscular mycorrhyzal (AM) symbiosis vary with the plants and fungal species involved in the association. Therefore, identification of the appropriate combinations of AM fungi (AMF) that interact synergistically to improve their benefits is of high significance. Here, three AM fungal compositions namely VT (Claroideoglomus sp., Funneliformis sp., Diversispora sp., Glomus sp., and Rhizophagus sp.) and BF (Glomus intraradices, G. microageregatum BEG and G. Claroideum BEG 210), and Funneliformis mosseae (Fm) were investigated with respect to the growth, gas exchange parameters, enzymes activities in Calvin cycles and related gene expression in cucumber seedlings. The results showed that VT, BF and Fm could successfully colonize cucumber root to a different degree with the colonization rates 82.38, 74.65, and 70.32% at 46 days post inoculation, respectively. The plant height, stem diameter, dry weight, root to shoot ratio of cucumber seedlings inoculated with AMF increased significantly compared with the non-inoculated control. Moreover, AMF colonization greatly increased the root activity, chlorophyll content, net photosynthetic rate, light saturated rate of the CO2 assimilation (Asat), maximum carboxylation rate (Vcmax) and maximum ribulose-1,5-bis-phosphate (RuBP) regeneration rate (Jmax), which were increased by 52.81, 30.75, 58.76, 47.00, 69.15, and 65.53% when inoculated with VT, respectively. The activities of some key enzymes such RuBP carboxylase/oxygenase (RuBisCO), D-fructose-1,6-bisphosphatase (FBPase), D-fructose-6-phosphatase (F6P) and ribulose-5-phosphate kinase (Ru5PK), and related gene expression involved in the Calvin cycle including RCA, FBPase, FBPA, SBPase, rbcS and rbcL were upregulated by AMF colonization. AMF inoculation also improved macro- and micro nutrient contents such as N, P, K, S, Ca, Cu, Fe, Mn, Mg, and Zn in roots. Further analysis revealed that inoculation with VT had relatively better effect on growth of cucumber seedling followed by BF and Fm, indicating that AMF composition consisting of distant AMF species may have a better effect than a single or closely related AMF spp. This study advances the understanding of plant responses to different AM fungi toward development of strategies on AMF-promoted vegetable production.

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Deoxynivalenol (DON) is a group B trichothecene and a common contaminant of crops worldwide. This toxin is known to cause a spectrum of diseases in animals and humans such as vomiting and gastroenteritis. Importantly, DON could inhibit the synthesis of protein and nucleonic acid and induce cell apoptosis in eukaryote cells. The transduction of signaling pathways is involved in the underlying mechanism of the cytotoxicity of DON. Mitogen-activated protein kinase and Janus kinase/signal transducer and activator of transcription seem to be two important signaling pathways and induce the inflammatory response by modulating the binding activates of specific transcription factors. This review mainly discussed the toxic mechanism of DON from the vantage point of signaling pathways and also assessed the profiles of DON and its metabolites in humans. Importantly, we conducted a human exposure risk assessment of DON from cereals, cereal-based foods, vegetables, water, and animal-derived foods in different countries. Some regular patterns of DON occurrence in these countries are suggested based on an analysis of global contamination with DON. This review should provide further insight for the toxic mechanism study of DON and human exposure risk assessment, thereby facilitating mycotoxin control strategies.

Introduction The transmission pathways of coronavirus disease 2019 (COVID‐19) remain not completely clear. In this case study the test for the novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in pharyngeal swab and anal swab were compared. Case presentation A 3‐month‐old girl was admitted to our hospital with COVID‐19. Her parents had both been diagnosed with COVID‐19. The results of pharyngeal swab and anal swab of the little girl were recorded and compared during the course of the disease. The oropharyngeal specimen showed negative result for SARS‐CoV‐2 on the 14th day after onset of the illness. However, the anal swab was still positive for SARS‐CoV‐2 on the 28th day after the onset of the illness. Conclusion The possibility of fecal‐oral transmission of COVID‐19 should be assessed. Personal hygiene during home quarantine merits considerable attention.

The universal symbiotic associations between arbuscular mycorrhizal fungi (AMF) and plant roots remarkably stimulate plant growth, nutrient uptake, and stress responses. The present study investigated the stress ameliorative potential of the AM fungus Funneliformis mosseae against chilling in tomato seedlings. AMF-inoculated tomato seedlings exhibited significantly higher fresh weight and dry weight than non-AMF control plants under both control (25/15°C) and low temperature (8°C/4°C) treatments. Under chilling stress, AMF inoculation significantly reduced the level of MDA, H 2 O 2 , and O 2 Á-along with increased calcium precipitates in the apoplast and vacuole of root cells compared with the non-AMF control. Furthermore, AMF inoculation induced activities of antioxidant enzymes and transcripts of related genes under chilling stress. Notably, AMF inoculation resulted in reduced redox state in root cells as evident by significantly increased content of reduced ascorbate, reduced glutathione, redox ratio, and the activity of L-galactono-1,4-lactone dehydrogenase in the tomato roots both under control and low temperature. Taken together, these results indicate that AMF could play an important role in optimizing chilling resistance by maintaining redox poise and calcium balance in tomato seedlings.