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Purpose: To investigate the potential protective effect of hydrogen sulfide against neural cell damage induced by a high-concentration of adenosine triphosphate (ATP).Methods: PC12 cells were incubated with ATP in order to induce cell damage. The extracellular level of H2S and protein expression of cystathionine-β-synthase (CBS) were determined. The PC12 cells pretreated with NaHS, aminooxyacetic acid (AOAA) and KN-62, prior to further incubation with ATP, and the effect of the treatments on cell viability was investigated.Results: High-concentration ATP induced cell death in PC12 cells, and this was accompanied by markedly increased contents of extracellular H2S and CBS expression (p < 0.05). The ATP-induced cytotoxicity was significantly compromised after pretreatment with H2S. (p < 0.05). The viability of PC12 cells pretreated with NaHS and AOAA was significantly higher than that of PC12 cells treated with ATP alone. In addition, the viability of ATP-treated PC12 cells was further markedly increased after pretreatment with NaHS and KN-62 (p < 0.05).Conclusion: ATP induced a concentration- and time-dependent cytotoxicity in PC12 cells via theendogenous H2S/CBS system. Supplementation with exogenous H2S mitigated the cell damageinduced by high concentration of ATP via a specific mechanism which may be specifically related to P2X7R.

BACKGROUND Ginger (Zingiber officinale Roscoe) is widely planted around the world. Owing to continuous planting, ginger is seriously affected by soilborne fungi, bacteria, and nematodes. Although preplant soil fumigation is an effective prevention strategy of soilborne diseases, individual fumigant and technology could not provide effective control of ginger soilborne disease. In our research, different combinations of soil fumigants and seed rhizome treatments were evaluated by monitoring the soil pathogens population, ginger growth, yield, and estimation of economic benefits. RESULTS Soil fumigation effectively reduced the population of soilborne pathogens, and chloropicrin had a better control effect on soilborne pathogens than dazomet did. Preplant soil fumigation and seed rhizome treatment not only provide good control of soilborne disease, but also reduced the incidence of plant foliar pest and disease. Average yield increase rate of seed rhizome treatment was 12.0%; the highest yield increase was 24.4%. The average cost of seed rhizome treatment only increased by about 2.86%, but the rate of net revenue increase for the seed rhizome treatment reached up to 19.1%. CONCLUSION Seed rhizome treatment is a very cost-effective soilborne disease control technology. In the management of soilborne diseases, the combined application of soil fumigation and seed rhizome treatment can reduce the risk of crops infected by soilborne diseases and ensure high and stable crop yields. © 2021 Society of Chemical Industry.

The highly-damaging root-knot nematode (Meloidogyne spp., RKN) cannot be reliably controlled using only a nematicide such as fosthiazate because of increasing pest resistance. In laboratory and greenhouse trials, we showed that chloropicrin (CP) or dazomet (DZ) synergized the efficacy of fosthiazate against RKN. The combination significantly extended the degradation half-life of fosthiazate by an average of about 1.25 times. CP or DZ with fosthiazate reduced the time for fosthiazate to penetrate the RKN cuticle compared to fosthiazate alone. CP or DZ combined with low or medium rate of fosthiazate increased the total cucumber yield, compared to the use of each product alone. A low-dose fosthiazate with DZ improved total yield more than a low dose fosthiazate with CP. Extending the half-life of fosthiazate and reducing the time for fosthiazate or fumigant to penetrate the RKN cuticle were the two features that gave the fumigant-fosthiazate combination its synergistic advantage over these products used singularly. This synergy provides the opportunity for farmers to use a low dose of fosthiazate which lowers the risk of RKN resistance. Farmers could combine DZ at 30 g m−2 with fosthiazate at a low rate of 0.375 g m−2 to control RKN and adequately control two major soil-borne diseases in cucumber greenhouses.

Crofton weed (Eupatorium adenophorum Spreng.) is an invasion in China and its spread speed rate has been faster than anticipated. Laboratory and greenhouse studies were employed to investigate the effect of heavy metal elements on several factors and the survivability mechanism of Crofton weed. Biochemical and ultrastructural methods revealed that this plant tolerated low concentrations of lead (Pb) or cadmium (Cd) individually or in combination as well, based on measurements of photosynthesis, the malondialdehyde and proline content, and the total electrolyte rate. After Pb, Cd or a mixture treatment, the total electrolyte rate, the malondialdehyde and proline content increased in Crofton weed, and leaves became darker than those of the control. Cellular ultrastructure observations showed that a cellular ultrastructure altered, including a thickened cell wall, chloroplast deformation, and damaged mitochondrial membrane. In addition, the activity of catalase, peroxidase and superoxide dismutase and the soluble protein content were affected after treatment with high concentrations of Pb, Cd or a combination. Taken together, these results suggest that Crofton weed has a high tolerance to Pb and Cd at low concentrations but becomes susceptible at high concentrations. These results may help control the environmental threat of Crofton weed or other invasive weed species.

Background Root-knot nematodes (Meloidogyne spp.), soil-borne diseases and weeds seriously reduce the commercial yield of tomatoes grown under protected cultivation in China. Allyl isothiocyanate (AITC), a natural product obtained from damaged Brassica tissues, was evaluated as a potential replacement for the fumigant methyl bromide (MB) for use in the greenhouse production of tomatoes in China. Results The dose-response assay indicates that AITC has high biological activity against major bacterial and fungal pathogens (EC50 of 0.225-4.199 mg L-1 ). The bioassay results indicate that AITC has good efficacy against root-knot nematodes (LC50 of 18.046 mg kg-1 ), and moderate efficacy against fungal pathogens (LC50 of 27.999-29.497 mg kg-1 ) and weeds (LC50 of 17.300-47.660 mg kg-1 ). The potting test indicates that AITC significantly improved plant vigor. Field trials indicate that AITC showed good efficacy against Meloidogyne spp. and Fusarium spp. (both ∼ 80%) as well as Phytophthora spp. and Pythium spp. (both ∼ 70%), and improved plant vigor and marketable yield. Conclusion AITC used as a soil fumigant (30-50 g m-2 ) effectively controlled major bacterial and fungal pathogens, root-knot nematode, weeds and increased plant vigor, yield and farmers' income in tomato cultivated under protected agriculture in China. © 2018 Society of Chemical Industry.

Combined use of chloropicrin (Pic) and 1,3-dicloropropene (1,3-D) is as effective as methyl bromide (MB) at controlling soilborne diseases in many trials and commercial uses. However, Pic and 1,3-D are both highly volatile and may pose strong exposure risks to humans and the environment. A gelatin capsule formulation containing Pic and 1,3-D has been developed to reduce exposure risks to workers and bystanders and improved application safety. We conducted two experiments in tomato and cucumber greenhouses located in Beijing and Qingdao, China, to study the efficacy of Pic plus 1,3-D gelatin capsules applied at different dosages and soil depths. Results indicated that both injection and gelatin capsules of Pic plus 1,3-D provided good control of soil nematodes and reduced disease index of Fusarium wilt and root-knot nematode. Plant yield of tomato and cucumber treated with gelatin capsules was similar to MB treatment. Based on our results, gelatin capsules applied at a soil depth of 15 cm provided better control of soilborne diseases and led to higher fruit yield compared to an application depth of 5 cm. In conclusion, a gelatin capsule of Pic plus 1,3-D is a promising and novel formulation, which not only shows good efficacy in controlling soilborne diseases, but also reduces potential exposure risks of fumigants.

The antifungal activity of oils extracted from Eupatorium adenophorum was tested against five phytopathogens in vitro. Oil extracts inhibited the mycelial growth of Phytophthora capsici which causes phytophthora blight in pepper. The minimum inhibitory concentration of oils against P. capsici was 500μg/ml after 7days incubation. At the ultrastructural level, oil extracts caused complete disorganization of intracellular organelles, cytoplasm depletion, disruption of cytoplasmic membranes and the cell wall. Membrane permeability increased with the increasing concentration of oil extracts. These results suggested that these oil extracts exhibited multiple modes of action including disruption of the cell membrane system. Furthermore, oil extracts combined with synthetic fungicides synergistically inhibited mycelial growth of P. capsici, which creates the possibility of reducing fungicide concentration needed to successfully control phytophthora blight in commercial pepper production. This study's use of multiple methods of analysis has increased our understanding of the mode of action of E. adenophorum oil extracts against P. capsici.

Chloropicrin (CP) is a potential alternative for methyl bromide as a soil fumigant given that the use of methyl bromide has become limited. However, little is known about how fumigation with CP affects the condition of the soil microbial community. In this study, 16S rRNA amplicon sequencing and quantitative PCR were combined to investigate the effect of CP on soil bacterial community. In total, 938,922 effective reads were obtained from 18 samples and clustered into 58,662 operational taxonomic units at a similarity cut-off of 97%. Both approaches showed that the primary structure of bacterial community in soil did not significantly change at the phylum level after fumigation, but CP had a significant impact on the abundance of the bacterial microbiome that was recovered and identified. Additionally, bacterial community diversity decreased significantly, and there was a shift in the predominant populations. Staphylococcus, Actinomadura, Acinetobacter and Streptomyces significantly decreased in number or disappeared, and Bacteroides, Lachnoclostridium, Pseudoalteromonas, Colwellia, Idiomarina and Cobetia became the new predominant populations. In addition, some species associated with biodegradation, such as Sphingomonas spp. and Rhodococcus spp., significantly increased in number. The abundance of ammonia-oxidizing archaea (AOA) were significantly inhibited, yet the abundance of ammonia-oxidizing bacteria (AOB) significantly increased, and denitrification was significantly promoted. These changes in bacterial flora can considerably impact soil function and health and lead to negative effects on the environment surrounding fumigated soils, indicating the need for proactive risk management. Our study provides useful information for environmental safety assessments of CP in China.

Main-chain nonlinear optical polymers based on novel chromophores with special structures presented good solubility in most of the organic solvents. Polymers PE-1 and PE-2 attained the thermal decomposition temperatures of 305 and 223 °C and glass transition temperatures of 113 and 108 °C, and exhibited only negligible decay in the SHG signal baked at 85 °C over hundreds of hours, respectively. The SHG coefficients of poled films from polymers PE-1 and PE-2 were 26.3 and 35.8 pm/V, respectively. These results indicated that this class of polymers can be used in the preparation of organic electro-optic devices.

Root-knot nematode is an important soil pest in horticulture crops and constrains the protected cultivation development after methyl bromide (MB) was phased out in China. Dimethyl disulfide (DMDS) exhibits excellent efficacy against nematodes. Laboratory experiments and field trials were set up to clarify DMDS dose, efficacy, and yield. A dose-response experiment using three methods showed that DMDS presented high efficacy against the nematode Meloidogyne incongnita. The LC50 values of direct fumigation activity in the dessicator method were 0.086 and 0.070 mg L-1 for DMDS and 1,3-D, 29.865 and 18.851 mg L-1 for DMDS and 1,3-D of direct contact activity in the small tube method, 6.438 and 3.061 mg L-1 for DMDS and 1,3-D of soil fumigation activity in the soil fumigation method, respectively. The field trials indicated that DMDS showed an excellent efficacy of 80%-94% on root-knot nematode applied at 10-100 g m-2 on tomato in Tongzhou, Beijing. The crop yields showed no significant difference after applying 10-80 g m-2 DMDS. Results indicate that DMDS applied at 10 g m-2 for controlling root-knot nematode in Beijing is cost effective. In conclusion, DMDS is an excellent soil fumigant that can be used for controlling root-knot nematode and can be an potential novel alternative to MB in China.

Global changes and human disturbances can strongly affect the quantity of aboveground litter entering soils, which could result in substantial cascading effects on soil biogeochemical processes in forests. Despite extensive reports, it is unclear how the variations in litter depth affect soil carbon and nitrogen cycling. The responses of soil carbon and nitrogen to the variability of litter inputs were examined in a coniferous&ndash, broadleaf mixed forest of Central China. The litter input manipulation included five treatments: no litter input, natural litter, double litter, triple litter, and quadruple litter. Multifold litter additions decreased soil temperature but did not affect soil moisture after 2.5 years. Reductions in soil pH under litter additions were larger than increases under no litter input. Litter quantity did not affect soil total organic carbon, whereas litter addition stimulated soil dissolved organic carbon more strongly than no litter input suppressed it. The triggering priming effect of litter manipulation on soil respiration requires a substantial litter quantity, and the impacts of a slight litter change on soil respiration are negligible. Litter quantity did not impact soil total nitrogen, and only strong litter fluctuations changed the content of soil available nitrogen (nitrate nitrogen and ammonium nitrogen). Litter addition enhanced soil microbial biomass carbon and nitrogen more strongly than no litter input. Our results imply that the impacts of multifold litter inputs on soil carbon and nitrogen are different with a single litter treatment. These findings suggest that variability in aboveground litter inputs resulting from environmental change and human disturbances have great potential to change soil carbon and nitrogen in forest ecosystems. The variability of aboveground litter inputs needs to be taken into account to predict the responses of terrestrial soil carbon and nitrogen cycling to environmental changes and forest management.

Herbicides are usually applied to agricultural fields following soil fumigation to provide effective weed control in high-value cash crops. However, phytotoxicity has been observed in ginger seedlings following the application of herbicides in fumigated fields. This study tested a mixture of herbicides (pendimethalin and oxyfluorfen) and several fumigant treatments in laboratory and field studies to determine their effect on the growth of ginger. The results showed that soil fumigation significantly (P0.05) extended the degradation period of these herbicides in the field and in laboratory studies. The half-life of pendimethalin was extended by an average of approximately 1.29 times in the field and 1.74 times in the laboratory. The half-life of oxyfluorfen was extended by an average of about 1.19 times in the field and 1.32 times in the laboratory. Moreover, the extended period of herbicide degradation in the fumigant and nonfumigant treatments significantly reduced ginger plant height, leaf number, stem diameter, and the chlorophyll content. The study concluded that applying a dose below the recommended rate of these herbicides in chloropicrin (CP) or CP + 1,3-dichloropropene fumigated ginger fields is appropriate, as application of the recommended herbicide dose in fumigated soil may be phytotoxic to ginger.

Sesquiterpenes in Eupatorium adenophorum are abundant in leaves and have great development potential as biopesticides. The toxicity of sesquiterpenes in immune cells and their corresponding immune functions are not fully understood. We evaluated the immunotoxicity of two cadinene sesquiterpenes 2-deoxo-2-(acetyloxy)-9-oxoageraphorone (DAOA) and 9-oxo-10,11-dehydro-agerophorone (ODA) by using histopathology and toxicology methods in vitro and in vivo in lymphocytes and natural killer cells in Kunming mice. The mice were given single doses of 75, 150 and 300 mg kg−1 body weight (BW) of DAOA/ODA every day for a week. Serious damage to the thymus and spleen was found in tissue images with clear lysis reduction numbers and a loosened arrangement of splenocytes and thymocytes to the mice treated with 150–300 mg kg−1 DAOA/ODA. Mice cytology was also affected with significant cellular alterations, increased splenocytes apoptosis rates (P

Background/Aims: Alzheimer's disease (AD) is characterized by two major hallmarks: the deposition and accumulation of β-amyloid (Aβ) peptide and hyperphosphorylated tau in intracellular neurofibrillary tangles. Sets of evidence show that leptin reduces Aβ production and tau phosphorylation. Herein, we investigated the signaling pathways activated by leptin, to extensively understand its mechanism. Methods: Western blotting was employed to assess the protein abundance of p-tau and BAX, MTT assay to decipher the cells viability. Results: Leptin decreased tau phosphorylation, an effect was dependent on the activation of JAK2. Conclusion: The data suggest that JAK2 is involved in AD-related pathways.

9-Oxo-agerophorone is a cadinene sesquiterpene, isolated from the leaves of Eupatorium adenophorum. This study evaluated the antimicrobial activity of 9-oxo-agerophorone against three strains of Ralstonia solanacearum and four pathogenic fungi, with an emphasis on the growth and morphogenesis of fungi at scanning electron microscopy level. The determination of minimal inhibitory concentrations demonstrated that 9-oxo-agerophorone exhibited moderate bactericidal activity against R. solanacearum strains. However, antifungal assays showed that 9-oxo-agerophorone has strong toxicity against Fusarium oxysporum, Bipolaris sorokiniana, Fusarium proliferatum, and Alternaria tenuissima with median lethal concentrations ranging from 0.476 to 0.357 mg ml−1 after 4 days incubation on potato dextrose agar medium. The main changes observed by scanning electron microscopy after 9-oxo-agerophorone treatment were fungal cell wall shrinkage, loss of conidia, formation of short branches in F. oxysporum and F. proliferatum, collapse, broken cell walls, and increased hyphae diameter in A. tenuissima. The tested treatments were also effective in inhibiting spore germination of Fusarium species. The results indicated that 9-oxo-agerophorone is a potential candidate as a phytotherapeutic agent for soil-borne fungal diseases.

Flame soil disinfestation (FSD) is a novel, promising non-chemical method to control soilborne nematodes, fungal and bacterial pathogens in China. The efficacy of FSD on soilborne nematodes, fungal and bacterial pathogens was evaluated during two field trials. The field trials revealed that the treatment with FSD once (FSD1) and treatment with FSD twice (FSD2) sharply reduced the total number of soilborne nematodes (>95%) and completely controlled Meloidogyne incognita in the soil. Both FSD1 and FSD2 also provided promising efficacy against soilborne Fusarium oxysporum (>44%), Phytophthora spp. (>47%) and Ralstonia solanacearum (>67%) on media. However, there was no significant difference between FSD1 and FSD2 in controlling soilborne nematodes, fungal and bacterial pathogens ( P = 0.05). Currently, there are two challenges to distribute the technology in China: its high cost and relatively low efficiency because of the low speed of application compared with soil chemical fumigation. Despite the drawbacks, FSD is still promising in organic agriculture for controlling soilborne nematodes, fungal and bacterial pathogens.

9-Oxo-10,11-dehydroageraphorone (ODA) is a cadinene sesquiterpene isolated from Eupatorium adenophorum. The antimicrobial activity of ODA was tested in vitro against four fungal strains and four bacterial strains. The fungitoxicity of ODA was evaluated by percentage radial growth inhibition using the poisoned food technique. ODA inhibited Fusarium oxysporum more than the other tested strains, giving EC50 values of 0.325 mg ml−1 at 48 h and 0.365 mg ml−1 at 96 h. Tests also revealed that ODA inhibits the germination of Fusarium oxysporum spores, reducing germination by 97 % at 0.5 mg ml−1 concentration. The minimum inhibitory concentrations (MIC) of ODA against four tested strains of Ralstonia solanacearum ranged from 0.25 to 1 mg ml−1 using a micro-well dilution method. In addition, our scanning electron microscopy study revealed previously unreported, pronounced effects of ODA on Fusarium oxysporum, Bipolaris sorokiniana, Fusarium proliferatum and Alternaria tenuissima, including marked shrinkage in the mycelia of all tested strains, swelling at the ends of Bipolaris sorokiniana mycelia and inhibition of spore production in the strains of Bipolaris sorokiniana and Fusarium proliferatum, providing firm evidence of the toxicity of ODA to these pathogenic fungi.

The combination of 1,3-dichloropropene+dimethyl disulfide (1,3-D+DMDS), which forms a pre-plant soil fumigant, can provide a substitute for the environmentally unfriendly methyl bromide (MB). Three greenhouse trials were performed to evaluate the root-knot nematode and soilborne fungi control efficacy in the suburbs of Beijing in China in 2010–2014. Randomized blocks with three replicates were designed in each trial. The combination of 1,3-D+DMDS (10+30 g m−2) significantly controlled Meloidogyne incognita, effectively suppressed the infestation of Fusarium oxysporum and Phytophthora spp., and successfully provided high commercial fruit yields (equal to MB but higher than 1,3-D or DMDS). The fumigant soil treatments were significantly better than the untreated controls. These results indicate that 1,3-D+DMDS soil treatments can be applied by soil injection or chemigation as a promising MB alternative against soilborne pests in cucumber in China.

Atmospheric nitrogen (N) deposition and land management practices (e.g. mowing) are two major threats to grassland soil seed banks and plant communities. However, the interactive effects of N addition and mowing on soil seed banks and plant communities are poorly quantified. A six-year field experiment was used to examine the responses of soil seed banks and plant communities to N addition (10 g N m−2 year−1) and mowing (once a year) in a temperate steppe in northern China. Soil seed bank and plant community structure were investigated with laboratory germination and visual examination. Mowing reversed the depletion of seed bank size under N deposition at soil depths of 2–5 cm and 5–10 cm. The main effects of N addition and mowing increased 1.1 species (0.25 × 0.25 m2) independently, but no interactions of N addition and mowing on seed richness were detected at soil depths of 5–10 cm. Nitrogen addition had few effects on plant cover, but mowing suppressed it by 11.5%, mainly by decreasing grass cover. Nitrogen addition stimulated plant height by 6.25 cm by enhancing grass height whereas mowing did not influence it. Nitrogen addition decreased 2.8 plant species due to negative effects of N addition on forb. The positive effects of mowing on forb richness exceed negative effects of mowing on grass richness, leading to a net increase of 2.8 plant species with mowing. Our findings suggest that changes in soil seed bank size under N deposition can be strongly modulated by land use. Both N deposition and mowing can increase seed richness in deep soil (5–10 cm). Mowing stimulated, but N deposition suppressed, plant species richness. This is potentially important for understanding the influences of land use and environmental changes on soil seed banks, with subsequent effects on plant community dynamic.