摘要:
A hydroponic study was conducted to determine the effects of single and/or combined application of different doses (0, 5 and 10 mu M L-1) of abscisic acid (ABA) and 6-benzylaminopurine (BAP) on cobalt (Co) accumulation, morpho-physiological and antioxidative defense attributes of tomato (Solanum lycopersicum L.) exposed to severe Co stress (400 mu M L-1). The single Co treatment (T1), prominently decreased tomato growth, relative water contents, photosynthetic pigments (chlorophyll a and chlorophyll b), whereas enhanced oxidative stress and Co accumulation in shoot and root tissues. Nonetheless, the supplementation of ABA and 6-BAP via nutrient media significantly (P < 0.05) enhanced plant biomass, root morphology and chlorophyll contents of tomato, compared to only Co treatment (T1). Moreover, the oxidative stress indicators such as malondialdehyde, proline and H2O2 contents were ameliorated through activation of enzymatic antioxidant activities i.e. ascorbate peroxidase, superoxide dismutase, catalase, and peroxidase, in growth modulator treatments in comparison to T1. The Co uptake, translocation (TF) and bioaccumulation factor (BAF) by shoot and root tissues of tomato were significantly reduced under all the treatments than that of T1. The supply of 6-BAP alone or in combination with ABA at 10 mu M L-1 application (T7) rate was found the most effective to reduce Co accumulation in the roots and shoots by 48.4% and 70.2% respectively than T1 treatment. It can be concluded that two plant growth modulators could improve the stress tolerance by inhibition of Co uptake in tomato plants. (C) 2020 Elsevier Ltd. All rights reserved.
摘要:
A visible light self-powered photoelectrochemical (PEC) aptasensor based on silver chromate particles, graphitic carbon nitride nanosheets and graphene oxide sheets (Ag(2)CrO(4)/g-C(3)N(4)/GO) for the ultrasensitive detection of chloramphenicol (CAP) was reported in this work. g-C(3)N(4) was considered to be the fundamental photoelectric material because of its great oxidation ability of photogenerated hole as well as excellent biocompatibility and low toxicity. However, the narrow light absorption range and rapid carrier recombination rate limit the application of pure g-C(3)N(4). Herein, Ag(2)CrO(4) and GO as photosensitizer were introduced to improve the photoelectric properties of g-C(3)N(4). The photocurrent of the developed ternary composite was about 3 times higher than that of pristine g-C(3)N(4), which proves it can be used as a suitable photoelectric active material. Moreover, the mechanism of Z-scheme electron transfer path was proved by density functional theory (DFT) calculation. The fabricated PEC aptasensor exhibited high sensitivity toward CAP with a wide liner response of 0.5 pM to 50 nM and a detection limit of 0.29 pM. The specific recognition mechanism and excellent sensing performance indicated this aptasensor could serve as a useful tool for selective and ultrasensitive CAP detection in practical analysis.
关键词:
resveratrol;absorption and metabolism;anti-inflammation;antioxidant;mechanism
摘要:
Resveratrol (3,4′,5-trihy- droxystilbene), a natural phytoalexin polyphenol, exhibits anti-oxidant, anti-inflammatory, and anti-carcinogenic properties. This phytoalexin is well-absorbed and rapidly and extensively metabolized in the body. Inflammation is an adaptive response, which could be triggered by various danger signals, such as invasion by microorganisms or tissue injury. In this review, the anti-inflammatory activity and the mechanism of resveratrol modulates the inflammatory response are examined. Multiple experimental studies that illustrate regulatory mechanisms and the immunomodulatory function of resveratrol both in vivo and in vitro. The data acquired from those studies are discussed.
摘要:
Surface area and porosity are important physical properties of biochar, playing a crucial role in many biochar applications, such as wastewater treatment and soil remediation. The production of engineered biochar with highly porous structure and large surface area has received extensive attention. This paper comprehensively reviewed the effects of biomass and pyrolysis parameters on the surface area and porosity of biochar. The composition of biomass feedstock and pyrolysis temperature are the major influencing factors. It is suggested that the lignocellulosic biomass is an outstanding candidate, wood and woody biomass in particular. Besides, moderate temperatures (400-700 degrees C) are suitable for the development of the pore structure. Further improvement can be implemented by additional treatments. Activation is the most widely used and effective way to promote biochar surface area and porosity, especially the chemical activation. Enhancement can also be achieved by using other treatment methods, such as carbonaceous materials coating, ball milling, and templating. Future research should focus on upgrading or developing treatment technology to achieve enhanced functionality and porous structure of biochar simultaneously. (C) 2020 Elsevier B.V. All rights reserved.
摘要:
The heavy metal pollution is a worldwide problem and has received a serious concern for the ecosystem and human health. In the last decade, remediation of the agricultural polluted soil has attracted great attention. Phytoremediation is one of the technologies that effectively alleviate heavy metal toxicity, however, this technique is limited to many factors contributing to low plant growth rate and nature of metal toxicities. Arbuscular mycorrhizal fungi (AMF) assisted alleviation of heavy metal phytotoxicity is a cost-effective and environment-friendly strategy. AMF have a symbiotic relationship with the host plant. The bidirectional exchange of resources is a hallmark and also a functional necessity in mycorrhizal symbiosis. During the last few years, a significant progress in both physiological and molecular mechanisms regarding roles of AMF in the alleviation of heavy metals (HMs) toxicities in plants, acquisition of nutrients, and improving plant performance under toxic conditions of HMs has been well studied. This review summarized the current knowledge regarding AMF assisted remediation of heavy metals and some of the strategies used by mycorrhizal fungi to cope with stressful environments. Moreover, this review provides the information of both molecular and physiological responses of mycorrhizal plants as well as AMF to heavy metal stress which could be helpful for exploring new insight into the mechanisms of HMs remediation by utilizing AMF.
关键词:
Mining and manufacturing;Rock weathering;Fertilizer and pesticide use;Principal component analysis;Mixed metal pollution;Surface water pollution
摘要:
This study collected past sampling data on total concentrations of 12 heavy metals (Cd, Pb, Cr, Hg, Zn, Cu, Ni, Al, Fe, Mn, As, and Co) in surface water bodies, i.e., 168 rivers and 71 lakes, from 1972 to 2017. The intent was to investigate the levels and sources of heavy metal pollution across five decades and five continents. Mean heavy metal concentrations in global river and lake water, and the number of heavy metals with concentrations greater than the published threshold limits as per the standards of both the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA) were generally lower in the 1970s and 1980s than in the 1990s, 2000s, and 2010s. Over time, heavy metal pollution in surface water has changed from single metal pollution to mixed metal pollution. Heavy metal concentrations in water, and the number of heavy metals with concentrations above the threshold limits for both WHO and USEPA standards were lower in the developed countries of Europe and North America, and higher in the developing countries of Africa, Asia, and South America. Over time, the main sources of metal pollution have changed from mining and manufacturing to rock weathering and waste discharge. The main metal sources differed across the five continents, with fertilizer and pesticide use, along with rock weathering, being dominant in Africa. Mining and manufacturing, along with rock weathering, were dominant in Asia and Europe. Mining and manufacturing, along with fertilizer and pesticide use, were dominant sources in North America, while four sources (mining and manufacturing, fertilizer and pesticide use, rock weathering, and waste discharge) were responsible for the majority of heavy metal pollution in the river and lake water bodies of South America. Additionally, implementing rigorous standards on metal emissions and recycling metals from wastewater are effective for controlling heavy metal source pollution. (C) 2020 The Authors. Published by Elsevier B.V.
摘要:
An effective adsorbent towards fluoroquinolone antibiotics was synthesized via a facile two-step approach, the co-precipitation of Fe, Mn with vinasse wastes and then pyrolysis under controlled conditions which denoted as FMB. Its adsorption behavior was examined based on a batch adsorption experiment of fluoroquinolone antibiotics pefloxacin (PEF) and ciprofloxacin (CIP). Experimental factors, such as pH, adsorbent dose, ionic strength, contact time and temperature have done a great deal to influence the adsorption of PEF and CIP. The FMB demonstrated excellent performance in reusability tests towards to both PEF and CIP, which showed that the recycling efficiency of PEF and CIP could remain similar to 55% and similar to 80% after five recycle cycles, respectively. The dominated adsorption mechanisms included pore filling effect, pi-pi stacking interaction, pi-pi EDA, hydrogen bonding and hydrophobicity. Overall, this work presented FMB was recognized as an effective, environmental-friendly and magnetically separable adsorbent for alleviating fluoroquinolone antibiotics contamination from water. (C) 2019 Elsevier B.V. All rights reserved.
摘要:
The application of pesticides reduces the loss of crops while simultaneously increasing crop productivity. However, the frequent use of pesticides can cause serious environmental problems due to their high accumulative and persistent nature. Recently, microalgae technology has received considerable success in the efficient treatment of pesticides pollution. In this review, the metabolic mechanisms responsible for the removal of pesticides are summarized based on previous studies. Different methods used to enhance the ability of microalgae to remove pesticides are critically evaluated. The recycling of microalgae biomass after wastewater treatment for biochar preparation and biodiesel production using the biorefinery approach is also introduced. Furthermore, we present potential future research directions to highlight the prospects of microalgae research in the removal of pesticides along with the production of value-added products.
摘要:
Biochar and compost have been widely used for pollution remediation of heavy metals in soil. However, little research was conducted to explore the efficiency of biochar, compost and their combination to reduce heavy metals availability, and the effects of their additive on soil biological properties are often neglected. Therefore, this study investigated the effects of biochar, compost and their combination on availability of heavy metals, physicochemical features and enzyme activities in soil. Results showed that adding amendments to polluted soil significantly altered soil properties. Compared to the separate addition of biochar or compost, their combined application was more effective to improve soil pH, organic matter (OM), organic carbon (TOC) and available potassium (AK). All amendments significantly decreased the availability of Cd and Zn, but slightly activated As and Cu. In addition, soil enzyme activities were activated by compost and inhibited by biochar, but exhibited highly variable responses to their combinations. Pearson correlation analysis indicated that electrical conductivity (EC) and AK were the most important environmental factors affecting metal availability and soil enzyme activities including dehydrogenase, catalase, beta-glucosidase, urease, acid and alkaline phosphatase, arylsulfatase except for protease and invertase. Availability of As, Cu, Cd and Zn affected dehydrogenase, catalase and urease activities. These results indicated that biochar, compost and their combination have significant effects on physicochemical features, metals availability and enzyme activities in heavy metal-polluted soil.
作者机构:
[Huang, Xingchuan; Sun, Tongjun; Li, Xin; Xu, Yan; Huang, Jianhua] Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada.;[Sun, Tongjun; Zhang, Yuelin; Li, X; Jetter, Reinhard; Li, Xin; Xu, Yan; Tian, Hainan; Sun, Yulin; Huang, Jianhua] Univ British Columbia, Dept Bot, Vancouver, BC V6T 1Z4, Canada.;[Schafer, Laurel; Jetter, Reinhard; Orduna, Alberto Ruiz; Verma, Vani] Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z4, Canada.;[Jing, Beibei] Natl Inst Biol Sci, Beijing 102206, Peoples R China.;[Tian, Hainan] Northeast Normal Univ, Sch Life Sci, Changchun, Peoples R China.
通讯机构:
[Li, Xin; Zhang, YL; Li, X] U;Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada.;Univ British Columbia, Dept Bot, Vancouver, BC V6T 1Z4, Canada.
摘要:
Two signal molecules, salicylic acid (SA) and N-hydroxypipecolic acid (NHP), play critical roles in plant immunity. The biosynthetic genes of both compounds are positively regulated by master immune-regulating transcription factors SARD1 and CBP60g. However, the relationship between the SA and NHP pathways is unclear. CALMODULIN-BINDING TRANSCRIPTION FACTOR 1 (CAMTA1), CAMTA2, and CAMTA3 are known redundant negative regulators of plant immunity, but the underlying mechanism also remains largely unknown. In this study, through chromatin immunoprecipitation and electrophoretic mobility shift assays, we uncovered that CBP60g is a direct target of CAMTA3, which also negatively regulates the expression of SARD1, presumably via an indirect effect. The autoimmunity of camta3-1 is suppressed by sard1 cbp60g double mutant as well as ald1 and fmo1, two single mutants defective in NHP biosynthesis. Interestingly, a suppressor screen conducted in the camta1/2/3 triple mutant background yielded various mutants blocking biosynthesis or signaling of either SA or NHP, leading to nearly complete suppression of the extreme autoimmunity of camta1/2/3, suggesting that the SA and NHP pathways can mutually amplify each other. Together, these results reveal that CAMTAs repress the biosynthesis of SA and NHP by modulating the expression of SARD1 and CBP60g, and that the SA and NHP pathways are coordinated to optimize plant immune response.
摘要:
Plant diseases reduce crop yields and threaten global food security, making the selection of disease-resistant cultivars a major goal of crop breeding. Broad-spectrum resistance (BSR) is a desirable trait because it confers resistance against more than one pathogen species or against the majority of races or strains of the same pathogen. Many BSR genes have been cloned in plants and have been found to encode pattern recognition receptors, nucleotide-binding and leucine-rich repeat receptors, and defense-signaling and pathogenesis-related proteins. In addition, the BSR genes that underlie quantitative trait loci, loss of susceptibility and nonhost resistance have been characterized. Here, we comprehensively review the advances made in the identification and characterization of BSR genes in various species and examine their application in crop breeding. We also discuss the challenges and their solutions for the use of BSR genes in the breeding of disease-resistant crops.
摘要:
Flax (Linum usitatissimum L.) is one of the oldest predominant industrial crops grown for seed, oil and fiber. The present study was executed to evaluate the morpho-physiological traits, biochemical responses, gas exchange parameters and phytoextraction potential of flax raised in differentially copper (Cu) spiked soil viz (0, 200, 400 and 600 mg Cu kg(-1) soil) under greenhouse pot experiment. The results revealed that flax plants were able to grow up to 400 mg kg(-1) Cu level without showing significant growth inhabitation while, further inference of Cu (600 mg kg(-1)) in the soil prominently inhibited flax growth and biomass accumulation. Compared to the control, contents of proline and malondialdehyde (MDA) were increased by 160.0% and 754.1% accordingly, at 600 mg Cu kg(-1) soil level. The Cu-induced oxidative stress was minimized by the enhanced activities of superoxide dismutase (SOD) by 189.2% and guaiacol peroxidase (POD) by 300.8% in the leaves of flax at 600 mg Cu kg(-1) soil level, compared to the untreated control. The plant Cu concentration was determined at 35, 70, 105 and 140 days after sowing (DAS) and results depicted that 16.9 times higher Cu concentration was accumulated in flax roots while little (14.9 times) was transported to the shoots at early stage of growth, i.e. 35 DAS. While at 140 DAS, Cu was highly (21.7 times) transported to the shoots while, only 12.3 times Cu was accumulated in the roots at 600 mg Cu kg(-1) soil level, compared to control. Meanwhile, Cu uptake by flax was boosted up to 253 mg kg(-1) from the soil and thereby extracted 43%, 39% and 41% of Cu at 200, 400 and 600 mg Cu kg(-1) soil level, compared to initial Cu concentration. Therefore, study concluded that flax has a great potential to accumulate high concentration of Cu in its shoots and can be utilized as phytoremediation material when grown in Cu contaminated soils.
摘要:
COVID-19 emerges as a pandemic disease with high mortality. Development of effective prevention and treatment is an urgent need. We reviewed TH17 responses in patients with SARS-CoV-2 and proposed an FDA approved JAK2 inhibitor Fedratinib for reducing mortality of patients with TH17 type immune profiles. Copyright (C) 2020, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.
期刊:
Proceedings of the National Academy of Sciences of the United States of America,2020年117(1):271-277 ISSN:0027-8424
通讯作者:
Wan, Jianmin;Yuan, Longping
作者机构:
[Liu, Yuqiang; Xiao, Shizhuo; Liu, Yanling; Fan, Dejia; Yang, Chunyan; Qiu, Zeyu; He, Jun; Wen, Peizheng; Huang, Jie; Shen, Zijie; Wan, Jianmin; Jiang, Ling; Chen, Xianian; Liu, Daoming] Nanjing Agr Univ, Jiangsu Plant Gene Engn Res Ctr, State Key Lab Crop Genet & Germplasm Enhancement, Nanjing 210095, Peoples R China.;[Xin, Yeyun; Yuan, Dingyang; Yuan, Longping] China Natl Hybrid Rice Res & Dev Ctr, State Key Lab Hybrid Rice, Changsha 410125, Peoples R China.;[Duan, Meijuan] Hunan Agr Univ, Coll Agron, Changsha 410006, Peoples R China.;[Wan, Jianmin] Chinese Acad Agr Sci, Inst Crop Sci, Natl Key Facil Crop Gene Resources & Genet Improv, Beijing 100081, Peoples R China.
通讯机构:
[Wan, Jianmin] N;[Yuan, Longping; Wan, Jianmin] C;Nanjing Agr Univ, Jiangsu Plant Gene Engn Res Ctr, State Key Lab Crop Genet & Germplasm Enhancement, Nanjing 210095, Peoples R China.;China Natl Hybrid Rice Res & Dev Ctr, State Key Lab Hybrid Rice, Changsha 410125, Peoples R China.;Chinese Acad Agr Sci, Inst Crop Sci, Natl Key Facil Crop Gene Resources & Genet Improv, Beijing 100081, Peoples R China.
关键词:
brown planthopper;lignin;phenylalanine ammonia-lyase;rice;salicylic acid
摘要:
Brown planthopper (BPH) is one of the most destructive insects affecting rice (Oryza sativa L.) production. Phenylalanine ammonia-lyase (PAL) is a key enzyme involved in plant defense against pathogens, but the role of PAL in insect resistance is still poorly understood. Here we show that expression of the majority of PALs in rice is significantly induced by BPH feeding. Knockdown of OsPALs significantly reduces BPH resistance, whereas overexpression of OsPAL8 in a susceptible rice cultivar significantly enhances its BPH resistance. We found that OsPALs mediate resistance to BPH by regulating the biosynthesis and accumulation of salicylic acid and lignin. Furthermore, we show that expression of OsPAL6 and OsPAL8 in response to BPH attack is directly up-regulated by OsMYB30, an R2R3 MYB transcription factor. Taken together, our results demonstrate that the phenylpropanoid pathway plays an important role in BPH resistance response, and provide valuable targets for genetic improvement of BPH resistance in rice.