In recent years,under the global climate change scenario,the occurrence of seasonal high temperature and temporal drought phenomena has increased in some subtropical regions. Consequently,the ...survival and growth of plants are restrained under the combined stress of elevated temperature and drought. In the present study,a pot experiment was performed at the Xiashu Forest Station of Nanjing Forestry University in 2013. One-year-old Broussonetia papyrifera seedlings were grown in 27-cm pots with brown loam soil,using a completely randomized design with four replicates.Seedlings were initially grown in the field environment and then transferred to a controlled greenhouse with three elevatedtemperature and soil-moisture treatments,and the effects of combined elevated temperature and drought stress on antioxidative enzyme activities and reactive oxygen species( ROS) metabolism were measured in B. papyrifera seedling leaves.The results indicated that under either elevated temperature or drought stress,the superoxide dismutase( SOD),peroxidase( POD),and catalase( CAT) activities of seedlings increased with the increase of stress level. Under the combined elevated temperature and drought stress,the activities of SOD and POD were higher than those under single temperature or drought stress,and increased over stress exposure time. Significant variation was observed in SOD activity of the seedlingsbetween combined stress treatments,revealing the synergistic effects of combined stress on SOD activities. Under the combined elevated temperature and drought stress,ROS,including O-2production rates and hydrogen peroxide( H2O2) and malondialdehyde( MDA) contents,were significantly higher than those under the single temperature or drought stress treatment,which suggests the limited role of antioxidant enzyme activities in alleviating the damage of the cell membrane of seedlings due to differences in ROS metabolite accumulation.
The current COVID-19 pandemic is caused by SARS CoV-2. To date, ∼463,000 people died worldwide due to this disease. Several attempts have been taken in search of effective drugs to control the spread ...of SARS CoV-2 infection. The main protease (Mpro) from SARS CoV-2 plays a vital role in viral replication and thus serves as an important drug target. This Mpro shares a high degree of sequence similarity (>96%) with the same protease from SARS CoV-1 and MERS. It was already reported that Broussonetia papyrifera polyphenols efficiently inhibit the catalytic activity of SARS CoV-1 and MERS Mpro. But whether these polyphenols exhibit any inhibitory effect on SARS CoV-2 Mpro is far from clear. To understand this fact, here we have adopted computational approaches. Polyphenols having proper drug-likeness properties and two repurposed drugs (lopinavir and darunavir; having binding affinity −7.3 to −7.4 kcal/mol) were docked against SARS CoV-2 Mpro to study their binding properties. Only six polyphenols (broussochalcone A, papyriflavonol A, 3'-(3-methylbut-2-enyl)-3',4',7-trihydroxyflavane, broussoflavan A, kazinol F and kazinol J) had interaction with both the catalytic residues (His41 and Cys145) of Mpro and exhibited good binding affinity (−7.6 to −8.2 kcal/mol). Molecular dynamic simulations (100 ns) revealed that all Mpro-polyphenol complexes are more stable, conformationally less fluctuated; slightly less compact and marginally expanded than Mpro-darunavir/lopinavir complex. Even the number of intermolecular H-bond and MM-GBSA analysis suggested that these six polyphenols are more potent Mpro inhibitors than the two repurposed drugs (lopinavir and darunavir) and may serve as promising anti-COVID-19 drugs.
Communicated by Ramaswamy H. Sarma
Combining phytoremediation plants and microorganisms is a promising method of remediating heavy metal contaminated soil. In this study, two manganese-tolerant strains were isolated from Mn slag and ...identified as Bacillus cereus HM5 and Bacillus thuringiensis HM7. These two Bacillus spp. have the ability to dissolve phosphorus, produce IAA and iron carrier. A pot experiment of Broussonetia papyrifera was conducted to explore potential of B. cereus HM5 and B. thuringiensis HM7 to improve effect of remedying Mn pollution by B. papyrifera. The strains were inoculated under different Mn treated (5 mmol/L, 50 mmol/L, Mn slag) respectively and the growth, root structure, root activity, physiological and biochemical characteristics of the leaves and accumulation of Mn for B. papyrifera were determinated. The effects of the soil environment to remediation were observed, the results showed that the biomass, total root length, surface area, crossings, tips, forks and root activity of B. papyrifera with inoculated strain were higher than those of the control group. The inoculation of these two Bacillus spp. increased the absorption of Mn by B. papyrifera and the concentration of Mn in the aerial parts of plants, indicating that the two strains could promote the growth of B. papyrifera and the accumulation of Mn. In addition, microbes reduced malonaldehyde content and the activities of antioxidant enzymes in leaves, suggesting that the two Bacillus spp. reduced Mn-induced oxidative stress. The principal component analysis showed that the added Bacillus strain prefer to promote plant root function maintenance and improve soil environment, rather than direct adsorption of heavy metals. These observations indicated that B. cereus HM5 and B. thuringiensis HM7 were valuable microorganisms, which could improve the remediating efficiency of B. papyrifera under Mn-contaminated soil.
•B. cereus HM5/B. thuringiensis HM7 improved the accumulation of Mn by B. papyrifera.•B. cereus HM5 and B. thuringiensis HM7 could reduce oxidative stress induced by Mn.•The strains promoted the growth of plant root system and improved soil environment.
•Efficient regeneration system was constructed by using Broussonetia papyrifera root as explants.•The best effect is to use three kinds of hormone at the same time, they cannot work effectively ...alone.•The explants of this system can obtain a large number of excellent clones in a short time.•It provides a basis for polyploid breeding to improve germplasm resources.
Broussonetia papyrifera (L.) L’Hér. ex Vent. is a perennial woody plant used as source material for papermaking, as woody forage, and as traditional Chinese medicine. In this study, an in vitro adventitious shoot induction procedure for B. papyrifera root explants was developed and evaluated the frequency of adventitious shoot regeneration. It showed that the culture medium, treatment with plant growth regulators, explant developmental stage, explant inoculation mode and genotype significantly affected explant regeneration efficiency. The results suggested that the best medium was half-strength Murashige and Skoog (1/2 MS) medium supplemented with 1.0 mg/L 6-benzyladenine (BA), 0.1 mg/L α-naphthalene acetic acid (NAA), 0.05 mg/L indole-3-butyric acid (IBA), explants derived from roots at the third development stage, inoculation by horizontal planting without cutting, and the genotype was GZ2, delivering a regeneration frequency of 84.44% and the maximum proliferation coefficient was 5.02. The optimal condition for inducing adventitious shoot rooting was 1/2 MS supplemented with 0.1 mg/L NAA. Under this condition, the maximum rooting rate of adventitious shoot was 82.22%, and the root grew strongly. Furthermore, the survival rate of transplanted seedlings was > 90%. Although the regeneration system was influenced by the B. papyrifera genotype, it is still effective for all genotypes studied. Using this novel system, B. papyrifera root explants can attain high induction rates and proliferation coefficients.
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•BP bark-derived, N-doped porous carbon (BPC) was fabricated for supercapacitors.•BPC was prepared by hydrothermal treatment followed by pyrolysis and activation.•The electrochemical ...tests exhibited a high specific capacitance of 320Fg−1.•Retention of 94% of its initial capacitance was achieved after 10000 cycles.
In this work, we present a facile approach to synthesize nitrogen-doped porous carbon materials via a two-step fabrication process using the stem bark of broussonetia papyrifera (BP) as the biomass precursor. Firstly, the BP stem bark is hydrothermally treated in a KOH aqueous solution. After filtration and drying, the hydrothermal product is directly subjected to simultaneous pyrolysis and activation, giving nitrogen-doped porous carbon materials. The morphology, structure and textural properties of the carbon materials are investigated by scanning electron microscopy, transmission electron microscopy, N2 sorption isotherms, and X-ray photoelectron spectroscopy. The obtained porous carbon exhibits a high BET surface area of 1212m2g−1 and an average pore size of 3.8nm. Such porous carbon shows outstanding capacitive performance (320Fg−1 at 0.5Ag−1), good rate capacitive behavior, and excellent cycling stability due to the synergistic effect of N, O-doped species, indicating a great potential for supercapacitors.
•Recovery of three forest sites under Broussonetia papyrifera was investigated.•Indigenous trees occurred in all stands but their degrees of recovery were variable.•The least recovered sites had the ...highest levels of anthropogenic disturbance.•%mulberry cover was -ly correlated with species richness and seedling density.•All sites showed potential to recover through natural regeneration and succession.
There are many studies on the applicability of natural regeneration for recovery of degraded forests. Studies of the potential of natural regeneration and succession to restore degraded forest areas under invasive exotic plants are few in comparison. This study examined the potential of these processes to bring about the recovery of large areas under the exotic paper mulberry Broussonetia papyrifera in Mabira Forest, Uganda. The areas of focus were degraded by farming but abandoned and invaded by mulberry 30 years ago. Sampling was conducted in three mulberry-dominant stands (Int 1, Int 2, and Hv) that were differentiated by the degree of mulberry cutting by local communities and other anthropogenic disturbances. Primary forest (Nt) was a fourth stand used as a reference. Data were collected using Modified-Whittaker Plots, transects and other plot types adapted to record impact of disturbance. Analyses of stem density showed that both mulberry and native trees occurred in all the stands in varying densities and age classes from seedling to tree class size. Non-metric multidimensional scaling showed Int 1 (a relatively undisturbed stand with fully grown mulberry) to be closest to Nt floristically, followed by Int 2 (a disturbed stand with fully grown mulberry). Hv (a disturbed stand with low stature mulberry) was least similar to Nt. Overall, Int 1 was closer to Nt than to any of the other stands; while Int 2 was closer to Hv than to Int 1 or to Nt. Most analyses of seedling and sapling densities and species diversity of native trees showed a pattern whereby Hv < Int 2 < Int 1 < Nt. Numbers of forest-typical species varied between stands but not significantly. Inter-stand differences in the levels of disturbance were pronounced with Hv and Int 2 having significantly higher incidences of illegal indigenous tree cutting and charcoal kilning than Int 1. Regressions of percent cover values on seedling densities, sapling densities and species richness showed negative relationships between mulberry cover and native tree seedling density and species richness but not sapling density. Indigenous tree sapling densities were positively correlated with indigenous tree species cover. These findings suggest that anthropogenic disturbance and to a smaller extent mulberry factors; and not differences in rates of species colonization and degrees of species performance explain the current state of recovery of the stands. Natural regeneration and succession therefore have potential to recover the degraded sites and reverse the dominance of mulberry if the ongoing human disturbance is stopped.
Liver injury caused by an overdose of acetaminophen (APAP) is a major public health problem. This study aimed to evaluate the effects of Broussonetia papyrifera polysaccharide (BPP) on liver injury ...and intestinal flora induced by APAP. The results showed that BPP could protect against APAP-induced liver injury, alleviate liver apoptosis, improve antioxidant capacity and enhance the liver’s detoxification ability to APAP. At the same time, BPP improved the intestinal flora disorder caused by APAP. More importantly, we found that the hepatoprotective effect of BPP disappeared after the depletion of gut microbiota in mice. Further, we reconstructed the intestinal flora structure of mice through fecal microbiota transplantation and found that the symptoms of APAP—induced liver injury were effectively alleviated. Overall, BPP was a potential hepatoprotective drug that could protect against APAP-induced liver injury and might be mediated by intestinal flora.
•Synergistic effects of DES with ethanol were investigated.•DES-E pretreatment results a better glucose yield.•Ethanol in pretreatment liquor protected β-O-4 from degradation and ...condensation.•Residue lignin after DES-E pretreatment showed less adsorption ability to cellulase.•DES-E pretreatment is a promising method in biorefinery.
A novel pretreatment system containing deep eutectic solvents and ethanol (DES-E) for synergistic carbohydrate conversion and delignification was reported in this study. The DES-E pretreatment resulted in an enhanced glucose yield compared to individual DES and ethanol pretreatment for the three tested biomass, including Broussonetia papyrifera, corn stover and pine. To further explore the delignification mechanism, the solubilized lignin and residual lignin from Broussonetia papyrifera was recovered and extracted, then thoroughly characterized. The highest total OH content was found in the DES-E solubilized lignin, which could be used as antioxidant. The presence of ethanol in pretreatment liquor could protect the β-O-4 substructure from breakage and reduce lignin condensation, which favors the subsequent enzymatic hydrolysis. Comparable glucose yield and delignification performance was achieved by recycled DES. DES-E pretreatment offers a promising method for lignin isolation and cellulose digestibility improvement simultaneously.
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