Metabonomic profiling of clubroot-susceptible and clubroot-resistant radish and the assessment of disease-resistant metabolites

Plasmodiophora brassicae causes a serious threat to cruciferous plants including radish (Raphanus sativus L.). Knowledge on the pathogenic regularity and molecular mechanism of P. brassicae and radish is limited, especially on the metabolism level. In the present study, clubroot-susceptible and clubroot-resistant cultivars were inoculated with P. brassicae Race 4, root hairs initial infection of resting spores (107 CFU/mL) at 24 h post-inoculation and root galls symptom arising at cortex splitting stage were identified on both cultivars. Root samples of cortex splitting stage of two cultivars were collected and used for untargeted metabonomic analysis. We demonstrated changes in metabolite regulation and pathways during the cortex splitting stage of diseased roots between clubroot-susceptible and clubroot-resistant cultivars using untargeted metabonomic analysis. We identified a larger number of differentially regulated metabolites and heavier metabolite profile changes in the susceptible cultivar than in the resistant counterpart. The metabolites that were differentially regulated in both cultivars were mostly lipids and lipid-like molecules. Significantly regulated metabolites and pathways according to the P value and variable important in projection score were identified. Moreover, four compounds, including ethyl α-D-thioglucopyranoside, imipenem, ginsenoside Rg1, and 6-gingerol, were selected, and their anti-P. brassicae ability and effects on seedling growth were verified on the susceptible cultivar. Except for ethyl α-D-thioglucopyranoside, the remaining could inhibit clubroot development of varing degree. The use of 5 mg/L ginsenoside Rg1 + 5 mg/L 6-gingerol resulted in the lowest disease incidence and disease index among all treatments and enhanced seedling growth. The regulation of pathways or metabolites of carbapenem and ginsenoside was further explored. The results provide a preliminary understanding of the interaction between radish and P. brassicae at the metabolism level, as well as the development of measures for preventing clubroot

Exogenous melatonin mediates radish (Raphanus sativus) and Alternaria brassicae interaction in a dose-dependent manner

Radish (Raphanus sativus L.) is an economically important vegetable worldwide, but its sustainable production and breeding are highly threatened by blight disease caused by Alternaria brassicae. Melatonin is an important growth regulator that can influence physiological activities in both plants and microbes and stimulate biotic stress resistance in plants. In this study, 0-1500 μM melatonin was exogenously applied to healthy radish seedlings, in vitro incubated A. brassicae, and diseased radish seedlings to determine the effects of melatonin on host, pathogen, and host-pathogen interaction. At sufficient concentrations (0-500 μM), melatonin enhanced growth and immunity of healthy radish seedlings by improving the function of organelles and promoting the biosynthesis of antioxidant enzymes, chitin, organic acid, and defense proteins. Interestingly, melatonin also improved colony growth, development, and virulence of A. brassicae. A strong dosage-dependent effect of melatonin was observed: 50-500 μM promoted host and pathogen vitality and resistance (500 μM was optimal) and 1500 μM inhibited these processes. Significantly less blight was observed on diseased seedlings treated with 500 μM melatonin, indicating that melatonin more strongly enhanced the growth and immunity of radish than it promoted the development and virulence of A. brassicae at this treatment concentration. These effects of MT were mediated by transcriptional changes of key genes as identified by RNA-seq, Dual RNA-seq, and qRT-PCR. The results from this work provide a theoretical basis for the application of melatonin to protect vegetable crops against pathogens

Hierarchically nanostructured porous TiO2(B) with superior photocatalytic CO2 reduction activity

Hierarchically nanostructured, porous TiO2(B) microspheres were synthesized by a microwave-assisted solvothermal method combined with subsequent heat treatment in air. The materials were carefully characterized by scanning and transmission electron microscopy, X-ray diffraction, CO2 adsorption, and a range of spectroscopies, including Raman, infrared, X-ray photoelectron and UV-Vis spectroscopy. The hierarchical TiO2 (B) particles are constructed by ultrathin nanosheets and possess large specific surface area, which provided many active sites for CO2 adsorption as well as CO2 conversion. The TiO2 (B) nanostructures exhibited marked photocatalytic activity for CO2 reduction to methane and methanol. Anatase TiO2 and P25 were used as the reference photocatalysts. Transient photocurrent measurement also proved the higher photoactivity of TiO2(B) than that of anatase TiO2. In-situ infrared spectrum was measured to identify the intermediates and deduce the conversion process of CO2 under illumination over TiO2(B) photocatalyst

In Vitro Techniques for Shipping of Micropropagated Plant Materials

Shipping of in vitro micro-cuttings in tubes or jars is a frequently used method as the plants are more likely to quickly reproduce and comply with quarantine regulations in plant germplasm distribution. However, these containers are fragile during transportation. To diminish the risk associated with the long-distance shipping of in vitro plants, a safe and widely applicable packing and conservation technique based on microplate and slow growth was developed in this study. Potato cultivar ZHB and ginger cultivar G-2 were used to optimize the system with microplates (96 wells), vacuum-sealed packaging, and slow-growth techniques. Under regular culture conditions, packing in vacuum-sealed microplates reduced the survival of ZHB and G-2 micro-cuttings to 85.8% and 20.0%, respectively, and regeneration to 61.8% and 0%, respectively. Reducing the temperature to 10 °C maintained the survival of ZHB and G-2 micro-cuttings in the range of 83.3–100% after 60 days. Exposure to darkness decreased the survival of G-2 and inhibited regrowth. Thus, conservation in darkness at 10 °C is suggested. The effects of iron concentration and plant growth retardants were further assessed. The addition of 1/4 MS medium combined with 100 mg/L chlormequat chloride (CCC) resulted in full survival and growth inhibition of plantlets, without malformation identified. Finally, incubation with 1/4 MS medium supplemented with 100 mg/L CCC in vacuum-sealed microplates at 10 °C in the dark resulted in high survival and suppressed germination. Sweet potato HXS was incubated as well to test the broad-spectrum applications of the technique; 100% survival and 6.7% germination was gained. Morphological indices of released cuttings recovered to control levels after two cycles of subculture in MS medium. A 0.1–0.2% genetic variation was detected by SSR and ISSR, suggesting genetic stability of the conserved samples. Finally, micro-cuttings were safely transported to cities located thousands of kilometers away without package and sample damage. Our results enable easy distribution of in vitro plant germplasms

A direct Z-scheme g-C3N4/SnS2 photocatalyst with superior visible-light CO2 reduction performance

Highlights - SnS2 quantum dots anchored in situ on g-C3N4 by a simple one-step hydrothermal method. - The internal electric field between g-C3N4 and SnS2 was confirmed. - Internal-electric-field-induced direct Z-scheme g-C3N4/SnS2 charge transfer for enhanced photocatalytic CO2 reduction. - In situ FTIR analysis further proved the suggested photocatalytic mechanism. Abstract Photocatalytic reduction of CO2 to solar fuels is an ideal approach to simultaneously solve the global warming and energy crisis issues. Constructing a direct Z-scheme heterojunction is an effective way to overcome the drawbacks of single-component or conventional heterogeneous photocatalysts for photocatalytic CO2 reduction. Here, a novel type of direct Z-scheme g-C3N4/SnS2 heterojunction was constructed by depositing SnS2 quantum dots onto the g-C3N4 surface in situ via a simple one-step hydrothermal method. l-Cysteine not only acted as the sulfur source, but also grafted ammine groups onto g-C3N4 in the hydrothermal process, which greatly enhanced the CO2 uptake of the composite. XPS analysis and density functional theory (DFT) calculation show that electron transfer occurred from g-C3N4 to SnS2, resulting in the formation of interfacial internal electric fields (IEF) between the two semiconductors at equilibrium. As a result, Z-scheme charge transfer took place under photoexcitation, with the electrons in SnS2 combining with the holes in g-C3N4, which improved the extraction and utilization of photoinduced electron in g-C3N4. The g-C3N4/SnS2 hybrid shows superior photocatalytic CO2 reduction as compared with individual g-C3N4 and SnS2, which should be attributed to the IEF-induced direct Z-scheme as well as improved CO2 adsorption capacity. In situ FTIR spectra illustrate that HCOOH appeared as an intermediate during the CO2 conversion, which can only be generated by g-C3N4 according to the energy level of the photoinduced electrons, further confirming the Z-scheme configuration for the g-C3N4/SnS2 system

DataSheet_1_Metabonomic profiling of clubroot-susceptible and clubroot-resistant radish and the assessment of disease-resistant metabolites.zip

Plasmodiophora brassicae causes a serious threat to cruciferous plants including radish (Raphanus sativus L.). Knowledge on the pathogenic regularity and molecular mechanism of P. brassicae and radish is limited, especially on the metabolism level. In the present study, clubroot-susceptible and clubroot-resistant cultivars were inoculated with P. brassicae Race 4, root hairs initial infection of resting spores (107 CFU/mL) at 24 h post-inoculation and root galls symptom arising at cortex splitting stage were identified on both cultivars. Root samples of cortex splitting stage of two cultivars were collected and used for untargeted metabonomic analysis. We demonstrated changes in metabolite regulation and pathways during the cortex splitting stage of diseased roots between clubroot-susceptible and clubroot-resistant cultivars using untargeted metabonomic analysis. We identified a larger number of differentially regulated metabolites and heavier metabolite profile changes in the susceptible cultivar than in the resistant counterpart. The metabolites that were differentially regulated in both cultivars were mostly lipids and lipid-like molecules. Significantly regulated metabolites and pathways according to the P value and variable important in projection score were identified. Moreover, four compounds, including ethyl α-D-thioglucopyranoside, imipenem, ginsenoside Rg1, and 6-gingerol, were selected, and their anti-P. brassicae ability and effects on seedling growth were verified on the susceptible cultivar. Except for ethyl α-D-thioglucopyranoside, the remaining could inhibit clubroot development of varing degree. The use of 5 mg/L ginsenoside Rg1 + 5 mg/L 6-gingerol resulted in the lowest disease incidence and disease index among all treatments and enhanced seedling growth. The regulation of pathways or metabolites of carbapenem and ginsenoside was further explored. The results provide a preliminary understanding of the interaction between radish and P. brassicae at the metabolism level, as well as the development of measures for preventing clubroot.</p

Prediction of methylation status using WGS data of plasma cfDNA for multi-cancer early detection (MCED)

Abstract Background Cell-free DNA (cfDNA) contains a large amount of molecular information that can be used for multi-cancer early detection (MCED), including changes in epigenetic status of cfDNA, such as cfDNA fragmentation profile. The fragmentation of cfDNA is non-random and may be related to cfDNA methylation. This study provides clinical evidence for the feasibility of inferring cfDNA methylation levels based on cfDNA fragmentation patterns. We performed whole-genome bisulfite sequencing and whole-genome sequencing (WGS) on both healthy individuals and cancer patients. Using the information of whole-genome methylation levels, we investigated cytosine–phosphate–guanine (CpG) cleavage profile and validated the method of predicting the methylation level of individual CpG sites using WGS data. Results We conducted CpG cleavage profile biomarker analysis on data from both healthy individuals and cancer patients. We obtained unique or shared potential biomarkers for each group and built models accordingly. The modeling results proved the feasibility to predict the methylation status of single CpG sites in cfDNA using cleavage profile model from WGS data. Conclusion By combining cfDNA cleavage profile of CpG sites with machine learning algorithms, we have identified specific CpG cleavage profile as biomarkers to predict the methylation status of individual CpG sites. Therefore, methylation profile, a widely used epigenetic biomarker, can be obtained from a single WGS assay for MCED

PLCE1 Promotes Esophageal Cancer Cell Progression by Maintaining the Transcriptional Activity of Snail

Esophageal cancer is among the most deadly malignant diseases. However, the genetic factors contributing to its occurrence are poorly understood. Multiple studies with large clinic-based cohorts revealed that variations of the phospholipase C epsilon (PLCE1) gene were associated with esophageal cancer susceptibility. However, the causative role of PLCE1 in esophageal cancer is not clear. We inactivated the functional alleles of PLCE1 by CRISPR/Cas9 genome editing technology. The resultant PLCE1 inactivated cells were analyzed both in vitro and in vivo. Our results showed that loss of PLCE1 dramatically decreased the invasion and proliferation capacity of esophageal carcinoma cells in vitro. Moreover, such PLCE1 inactivated tumor grafts exhibited significantly decreased tumor size in mice. We found that PLCE1 was required to maintain protein level of snail a key transcription factor responsible for invasion. Our further transcriptomic data revealed that deficient cells were significantly decreased in expression of genes enriched as targets of Snail. Strikingly, recovery of Snail protein at least partially rescued the invasion and proliferation capacity in PLCE1 inactivated cells. In ESCC clinical specimens, PLCE1 was correlated with tumor stage (P < .0001). Interestingly, PLCE1 expression was positively correlated Snail by immunohistochemistry in such specimens (P < .0001). Therefore, our functional experiments showed the essential roles of PLCE1 in esophageal carcinoma cells and provided evidences that targeting PLCE1 and its downstream molecules could be effective therapies for esophageal cancer