Cereal crop production is severely affected by seed-borne bacterial diseases across the world. Locally occurring disease resistance in various crops remains elusive. Here, we have observed that rice ...plants of the same cultivar can be differentiated into disease-resistant and susceptible phenotypes under the same pathogen pressure. Following the identification of a seed-endophytic bacterium as the resistance-conferring agent, integration of high-throughput data, gene mutagenesis and molecular interaction assays facilitated the discovery of the underlying mode of action. Sphingomonas melonis that is accumulated and transmitted across generations in disease-resistant rice seeds confers resistance to disease-susceptible phenotypes by producing anthranilic acid. Without affecting cell growth, anthranilic acid interferes with the sigma factor RpoS of the seed-borne pathogen Burkholderia plantarii, probably leading to impairment of upstream cascades that are required for virulence factor biosynthesis. The overall findings highlight the hidden role of seed endophytes in the phytopathology paradigm of 'disease triangles', which encompass the plant, pathogens and environmental conditions. These insights are potentially exploitable for modern crop cultivation threatened by globally widespread bacterial diseases.
The leaf area index (LAI) is not only an important parameter used to describe the geometry of vegetation canopy but also a key input variable for ecological models. One of the most commonly used ...methods for LAI estimation is to establish an empirical relationship between the LAI and the vegetation index (VI). However, the LAI-VI relationships had high seasonal variability, and they differed among phenophases and VIs. In this study, the LAI-VI relationships in different phenophases and for different VIs (i.e., the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) and near-infrared reflectance of vegetation (NIRv)) were investigated based on 82 site-years of LAI observed data and the Moderate Resolution Imaging Spectroradiometer (MODIS) VI products. Significant LAI-VI relationships were observed during the vegetation growing and declining periods. There were weak LAI-VI relationships (p > 0.05) during the flourishing period. The accuracies for the LAIs estimated with the piecewise LAI-VI relationships based on different phenophases were significantly higher than those estimated based on a single LAI-VI relationship for the entire vegetation active period. The average root mean square error (RMSE) ± standard deviation (SD) value for the LAIs estimated with the piecewise LAI-VI relationships was 0.38 ± 0.13 (based on the NDVI), 0.41 ± 0.13 (based on the EVI) and 0.41 ± 0.14 (based on the NIRv), respectively. In comparison, it was 0.46 ± 0.13 (based on the NDVI), 0.55 ± 0.15 (based on the EVI) and 0.55 ± 0.15 (based on the NIRv) for those estimated with a single LAI-VI relationship. The performance of the three VIs in estimating the LAI also varied among phenophases. During the growing period, the mean RMSE ± SD value for the estimated LAIs was 0.30 ± 0.11 (LAI-NDVI relationships), 0.37 ± 0.11 (LAI-EVI relationships) and 0.36 ± 0.13 (LAI-NIRv relationships), respectively, indicating the NDVI produced significantly better LAI estimations than those from the other two VIs. In contrast, the EVI produced slightly better LAI estimations than those from the other two VIs during the declining period (p > 0.05), and the mean RMSE ± SD value for the estimated LAIs was 0.45 ± 0.16 (LAI-NDVI relationships), 0.43 ± 0.23 (LAI-EVI relationships) and 0.45 ± 0.25 (LAI-NIRv relationships), respectively. Hence, the piecewise LAI-VI relationships based on different phenophases were recommended for the estimations of the LAI instead of a single LAI-VI relationship for the entire vegetation active period. Furthermore, the optimal VI in each phenophase should be selected for the estimations of the LAI according to the characteristics of vegetation growth.
Critical patients with the coronavirus disease 2019 (COVID-19), even those whose nucleic acid test results had turned negative and those receiving maximal medical support, have been noted to progress ...to irreversible fatal respiratory failure. Lung transplantation (LT) as the sole therapy for end-stage pulmonary fibrosis related to acute respiratory distress syndrome has been considered as the ultimate rescue therapy for these patients.
From February 10 to March 10, 2020, three male patients were urgently assessed and listed for transplantation. After conducting a full ethical review and after obtaining assent from the family of the patients, we performed three LT procedures for COVID-19 patients with illness durations of more than one month and extremely high sequential organ failure assessment scores.
Two of the three recipients survived post-LT and started participating in a rehabilitation program. Pearls of the LT team collaboration and perioperative logistics were summarized and continually improved. The pathological results of the explanted lungs were concordant with the critical clinical manifestation, and provided insight towards better understanding of the disease. Government health affair systems, virology detection tools, and modern communication technology all play key roles towards the survival of the patients and their rehabilitation.
LT can be performed in end-stage patients with respiratory failure due to COVID-19-related pulmonary fibrosis. If confirmed positive-turned-negative virology status without organ dysfunction that could contraindicate LT, LT provided the final option for these patients to avoid certain death, with proper protection of transplant surgeons and medical staffs. By ensuring instant seamless care for both patients and medical teams, the goal of reducing the mortality rate and salvaging the lives of patients with COVID-19 can be attained.
Herein we report a novel and straightforward protocol for the construction of valuable gem‐BPs by means of proton‐coupled electron‐transfer (PCET)‐triggered enamido C(sp2)−H diphosphorylation. This ...reaction represents a rare example of realizing the challenging double C−P bond formation at a single carbon atom, thus providing facile access to a broad variety of structurally diverse bisphosphonates from simple enamides under silver‐mediated conditions. Initial mechanistic studies demonstrated that the diphosphorylation involves two rounds of PCET‐initiated radical relay process.
C−P bond formation: By taking advantage of a PCET‐triggered radical relay process, a new general method to versatile valuable functionalized gem‐bisphosphonates is described (see scheme).
An increasing number of studies have shown that long noncoding RNAs (lncRNAs) play essential roles in tumor initiation and progression. LncRNAs act as tumor promoters or suppressors by targeting ...specific genes via epigenetic modifications and competing endogenous RNA (ceRNA) mechanisms. In this study, we explored the function and detailed mechanisms of long intergenic nonprotein coding RNA 673 (LINC00673) in breast cancer progression.
Quantitative real-time PCR (qRT-PCR) was used to examine the expression of LINC00673 in breast cancer tissues and in adjacent normal tissues. Gain-of-function and loss-of function experiments were conducted to investigate the biological functions of LINC00673 in vitro and in vivo. We also explored the potential role of LINC00673 as a therapeutic target using antisense oligonucleotide (ASO) in vivo. RNA sequencing (RNA-seq), dual-luciferase reporter assays, chromatin immunoprecipitation (ChIP) assay, and rescue experiments were performed to uncover the detailed mechanism of LINC00673 in promoting breast cancer progression.
In the present study, LINC00673 displayed a trend of remarkably increased expression in breast cancer tissues and was associated with poor prognosis in breast cancer patients. Importantly, LINC00673 depletion inhibited breast cancer cell proliferation by inhibiting the cell cycle and increasing apoptosis. Furthermore, ASO therapy targeting LINC00673 substantially suppressed breast cancer cell proliferation in vivo. Mechanistically, LINC00673 was found to act as a ceRNA by sponging miR-515-5p to regulate MARK4 expression, thus inhibiting the Hippo signaling pathway. Finally, ChIP assay showed that the transcription factor Yin Yang 1 (YY1) could bind to the LINC00673 promoter and increase its transcription in cis.
YY1-activated LINC00673 may exert an oncogenic function by acting as a sponge for miR-515-5p to upregulate the MARK4 and then inhibit Hippo signaling pathway, and may serve as a potential therapeutic target.
Tebuconazole is widely used as fungicide and has frequently been detected at elevated concentrations in environmental media. To characterize the potential toxicity of tebuconazole on vertebrate and ...humans. Using zebrafish as a vertebrate model, the toxic effects in liver that produced by low-toxic concentrations of tebuconazole were assessed in adult zebrafish. We further focused on tebuconazole-induced toxicity and its possible mechanism in larval zebrafish using a hepatotoxicity assay. The induction of oxidative stress in adult fish was evaluated by superoxide dismutase (T-SOD), catalase (CAT), peroxidase (POD), glutathione S-transferase (GST) activity, and the increased aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio. Significantly increased enzyme activity was observed in the liver of male and female fish at both exposure and depuration stage. Exposure to maximum non-lethal (MNLC) concentration of tebuconazole from 72 to 120 h post-fertilization (hpf) affected the liver size and yolk retention in larval zebrafish. Decreased fluorescence intensity was observed in larval Tg(Apo14:GFP) zebrafish, indicating liver degeneration after tebuconazole treated. Histopathological examination confirmed the alterations in liver histoarchitecture in exposed zebrafish. Significant 1.28-fold and 1.65-fold increases in reactive oxygen species levels were observed in juveniles exposed to MNLC and lethal concentration 10 (LC10) group, respectively. The acridine orange staining assay showed that apoptotic cells occurred in the liver regions. These results indicated that tebuconazole exposure resulted in impacts on the ecological risk in fish and vertebrate. Overall, the present study suggested further research in needed to better understand the tebuconazole-induced toxicity mechanism that associated with oxidative stress.
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•Tebuconazole induced hepatotoxicity in both adult and larval zebrafish.•Tg(Apo14: GFP) zebrafish was used for hepatotoxicity assay.•Histopathological results showed alterations in liver histoarchitecture after exposure.•ROS-mediated pathway might induce apoptosis in zebrafish after tebuconazole exposure.
•Application conditions for VIs in constructing the LAI seasonal trajectory were assessed.•The optimal VI for different ranges of LAI is suggested for LAI estimation.•The VIRE have the potential to ...develop a universe model for estimating LAI.
Leaf area index (LAI) is a required input for various ecological and crop models. To investigate the application conditions of various vegetation indices (VIs), especially the VIs constructed by red-edge band (VIRE) for estimating LAI, six VIs derived from Medium Resolution Imaging Spectrometer (MERIS) data were used to construct LAI seasonal trajectory for different vegetation types at 15 sites. The PROSAIL model combined with the Extended Fourier Amplitude Sensitivity Test (EFAST) method was adopted to explore the influences and physical basis of canopy biophysical and non-canopy variables on the construction of LAI seasonal trajectory using VIs. For deciduous forests, the normalized difference vegetation index (NDVI) had the highest sensitivity to LAI when LAI < 2, while the RE normalized difference vegetation index (NDVIRE) had the highest sensitivity when LAI > 2. For evergreen forests, there were no obvious differences among the sensitivities of six VIs to LAI when LAI < 5, while the RE chlorophyll index (CIRE) had the highest sensitivities when LAI > 5. For crops, all the VIs had the similar sensitivities at LAI < 3, while the CIRE and MERIS terrestrial chlorophyll index (MTCI) were most sensitive to LAI variations at LAI > 3. For all three types of vegetation, the VIRE maintained relatively high sensitivity to LAI over the whole range of LAI, especially at high LAI values. The VIs were most affected by chlorophyll content (Cab) and average leaf inclination angle (ALA); their total contribution was about 85%. However, the influence of ALA on VIRE was relatively weak, implying that the VIRE had the potential to establish a universal model for LAI estimation among different vegetation types. Therefore, the optimal VIs over different ranges of LAI were suggested to estimate LAI. In addition, the VIRE should be a preferred choice for estimating LAI to reduce the simulation errors of seasonal LAI, if the RE band is available.
Efficient and low-cost electrode materials for the electrochemiluminescence (ECL) reaction are highly desired for the future detection technology. Herein, we report an efficient bottom-up pathway to ...synthesize phosphorus-doped graphitic carbon nitride nanosheets (PCNNs) by ultra-rapid microwave irradiation. When the melamine precursor is modified with a 5 wt% diammonium hydrogen phosphate, the as-synthesized PCNNs display a very thin thickness (about 2 nm), good dispersibility in water (still stable after 2 weeks), low electron-transfer resistance (7499 Ω) and suitable band gap (2.7 eV). More importantly, the ECL intensity of the optimal PCNNs at low potential (− 1.2 to 0 V) is 26.7 times stronger than that of pure graphitic carbon nitride. The key to the excellent ECL property primarily lies in the more satisfactory sheet-like structure, faster electron transfer and better water affinity.
In this study, we report that phase separation of water/acetonitrile solution to a biphasic system can be induced by the presence of an acidic ionic liquid, i.e., 1-methyl-3-(butyl-4-chlorosulfonyl) ...imidazolium chlorosulfate (MBCImSO3Cl), which allows to produce pseudo ternary phase of the/water/actonitrile/MBCImSO3Cl system at room temperature. Based on this finding, an efficient and recyclable aqueous acetonitrile biphasic system is established for catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) in the presence of MBCImSO3Cl at low temperature in a shorter period of time. The ionic liquids remaining in the organic phase can be efficiently removed by simple treatment with alumina. This leaves only HMF, with a yield of up to 88.7%, in the acetonitrile phase, which could be easily removable.
Heavy metal contaminants and nutrient deficiencies in soil negatively affect crop growth and human health. The plant cadmium resistance (PCR) protein transports heavy metals. The abundance of PCR is ...correlated with that of cell number regulator (CNR) protein, and the two proteins have similar conserved domains. Hence, CNR might also participate in heavy metal transport. We isolated and analyzed TaCNR5 from wheat (Triticum aestivum). The expression level of TaCNR5 in the shoots of wheat increased under cadmium (Cd), zinc (Zn), or manganese (Mn) treatments. Transgenic plants expressing TaCNR5 showed enhanced tolerance to Zn and Mn. Overexpression of TaCNR5 in Arabidopsis increased Cd, Zn, and Mn translocation from roots to shoots. The concentrations of Zn and Mn in rice grains were increased in transgenic plants expressing TaCNR5. These roles of TaCNR5 in the translocation and distribution of heavy metals mean that it has potential as a genetic biofortification tool to fortify cereal grains with micronutrients.
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