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Floral initiation is regulated by various genetic pathways in response to light, temperature, hormones and developmental status; however, the molecular mechanisms underlying the interactions between different genetic pathways are not fully understood. Here, we show that the photoresponsive gene FOF2 (F-box of flowering 2) negatively regulates flowering. FOF2 encodes a putative F-box protein that interacts specifically with ASK14, and its overexpression results in later flowering under both long-day and short-day photoperiods. Conversely, transgenic plants expressing the F-box domain deletion mutant of FOF2 (FOF2ΔF), or double loss of function mutant of FOF2 and FOL1 (FOF2-LIKE 1) present early flowering phenotypes. The late flowering phenotype of the FOF2 overexpression lines is suppressed by the flc-3 loss-of-function mutation. Furthermore, FOF2 mRNA expression is regulated by autonomous pathway gene FCA, and the repressive effect of FOF2 in flowering can be overcome by vernalization. Interestingly, FOF2 expression is regulated by light. The protein level of FOF2 accumulates in response to light, whereas it is degraded under dark conditions via the 26S proteasome pathway. Our findings suggest a possible mechanistic link between light conditions and the autonomous floral promotion pathway in Arabidopsis.

Single-domain antibodies, including variable domains of the heavy chains of heavy chain-only antibodies (VHHs) from camelids and variable domains of immunoglobulin new antigen receptors (VNARs) from cartilaginous fish, show the therapeutic potential of targeting antigens in a cytosol reducing environment. A large proportion of single-domain antibodies contain non-canonical cysteines and corresponding non-canonical disulfide bonds situated on the protein surface, rendering them vulnerable to environmental factors. Research on non-canonical disulfide bonds has been limited, with a focus solely on VHHs and utilizing only cysteine mutations rather than the reducing agent treatment. In this study, we examined an anti-lysozyme VNAR and an anti-BC2-tag VHH, including their non-canonical disulfide bond reduced counterparts and non-canonical cysteine mutants. Both the affinity and stability of the VNARs and VHHs decreased in the non-canonical cysteine mutants, whereas the reduced-state samples exhibited decreased thermal stability, with their affinity remaining almost unchanged regardless of the presence of reducing agents. Molecular dynamics simulations suggested that the decrease in affinity of the mutants resulted from increased flexibility of the CDRs, the disappearance of non-canonical cysteine–antigen interactions, and the perturbation of other antigen-interacting residues caused by mutations. These findings highlight the significance of non-canonical cysteines for the affinity of single-domain antibodies and demonstrate that the mutation of non-canonical cysteines is not equivalent to the disruption of non-canonical disulfide bonds with a reducing agent when assessing the function of non-canonical disulfide bonds. [ABSTRACT FROM AUTHOR]

The discovery of concretions of Chang 7 shale formations in the Ordos basin has increased interest in the exploration of lacustrine carbonate genesis in these basins. In this paper, these concretions were sampled and used in major, trace, and isotopic geochemistry tests. We used a microscope to investigate these concretions, and the results showed that the concretions consisted of carbonate rocks, the calcite was hydrothermal calcite, and obvious hydrothermal activity was present in the Yanchang period. We used seismic data to interpret the faults, and we determined that tectonic activity was relatively frequent in the middle–late Triassic period and that the faults were channels for hydrothermal upwelling. During the middle–late Triassic period, tectonic movement of the basin occurred, and synsedimentary faults developed in the Yanchang Formation. As deep hydrothermal gushers rose through faults and fractures, they carried particles upward through the deep limestone strata. When the hydrothermal gushers reached the lake bottom, the particles precipitated and eventually formed concretions via diagenesis. [ABSTRACT FROM AUTHOR]

Background : The coronavirus disease 2019 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected more than 210 million individuals globally and resulted in over 4 million deaths since the first report in December 2019. The early use of traditional Chinese medicine (TCM) for light and ordinary patients, can rapidly improve symptoms, shorten hospitalization days and reduce severe cases transformed from light and normal. Many TCM formulas and products have a wide application in treating infectious and non-infectious diseases. Polygonum cuspidatum Sieb. et Zucc. ( P. cuspidatum ), is an important Traditional Chinese Medicine with actions of clearing away heat and eliminating dampness, draining the gallbladder to relieve jaundice, removing blood stasis to alleviate pain, resolving phlegm and arrest cough. In the search for anti-SARS-CoV-2, P. cuspidatum was recommended as as a therapeutic drug of COVID-19 pneumonia.In this study, we aimed to identifies P. cuspidatum is the potential broad-spectrum inhibitor for the treatment of coronaviruses infections. Methods : In the present study , we infected human malignant embryonal rhabdomyoma (RD) cells with the OC43 strain of the coronavirus, which represent an alternative model for SARS-CoV-2 and then employed the cell viability assay kit for the antiviral activity. We combined computer aided virtual screening to predicte the binding site and employed Surface plasmon resonance analysis (SPR) to comfirm the interaction between drugs and coronavirus. We employed fluorescence resonance energy transfer technology to identify drug's inhibition in the proteolytic activity of 3CLpro and Plpro. Results : Based on our results, polydatin and resveratrol derived from P. cuspidatum significantly suppressed HCoV-OC43 replication. 50% inhibitory concentration (IC 50 ) values of polydatin inhibited SARS-CoV-2 Mpro and Plpro, MERS Mpro and Plpro were 18.66, 125, 14.6 and 25.42 μm, respectively. IC 50 values of resveratrol inhibited SARS-CoV-2 Mpro and Plpro, MERS Mpro and Plpro were 29.81 ,60.86, 16.35 and19.04 μM, respectively. Finally, SPR assay confirmed that polydatin and resveratrol had high affinity to SARS-CoV-2, SARS-CoV 3Clpro, MERS-CoV 3Clpro and PLpro protein. Conclusions : we identified the antiviral activity of flavonoids polydatin and resveratrol on RD cells. Polydatin and resveratrol were found to be specific and selective inhibitors for SARS-CoV-2, 3CLpro and PLpro, viral cysteine proteases. In summary, this study identifies P. cuspidatum as the potential broad-spectrum inhibitor for the treatment of coronaviruses infections., (© 2021 The Author(s). Published by BRI.)