In order to determine antioxidant activity, the five extracts/fractions of red onion peel were studied for their total content of phenolics (TPC), flavonoids (TFC), antioxidant activity (AOA), free ...radical scavenging activity (FRSA), assayed by DPPH radical in the terms of anti-radical power (ARP) and reducing power (RP), expressed as ascorbic acid equivalents (ASE)/ml. High TPC (384.7±5.0mg GAE/g), TFC (165.2±3.2mg QE/g), AOA (97.4±7.6%), ARP (75.3±4.5) and RP (1.6±0.3 ASE/ml) were found for the ethyl acetate (EA) fraction. EA fraction had markedly higher antioxidant capacity than butylated hydroxytoluene (BHT) in preventive or scavenging capacities against FeCl3-induced lipid peroxidation, protein fragmentation, hydroxyl (site-specific and non-site-specific), superoxide anion and nitric oxide radicals. EA fraction also showed dose dependent antimutagenic activity by following the inhibition of tobacco-induced mutagenicity in Salmonella typhimurium strains (TA102) and hydroxyl radical-induced nicking in plasmid pUC18 DNA. HPLC and MS/MS analysis showed the presence of ferulic, gallic, protocatechuic acids, quercetin and kaempferol. The large amount of polyphenols contained in EA fraction may cause its strong antioxidant and antimutagenic properties. This information shows that EA fraction of red onion peel can be used as natural antioxidant in nutraceutical preparations.
AIMS: To investigate the efficacy of Trichoderma harzianum NBRI‐1055 (denoted as ‘T‐1055’) in suppression of seedling blight of sunflower caused by Rhizoctonia solani Kühn and their impact on host ...defence responses. METHODS AND RESULTS: T‐1055 was applied as seed treatment, soil application and combined application (seed treatment + soil application). Higher protection afforded by combined application of T‐1055 was associated with the marked induction of phenylalanine ammonia‐lyase (PAL), polyphenol oxidase (PPO), peroxidase (PO) and cinnamyl alcohol dehydrogenase (CAD) activities. The activities of PAL and PPO reached maximum at 10 days after sowing (DAS), while PO and CAD levels reached maximum at 12 DAS. This was further supported by the accumulation of total phenolic content that showed an increase up to threefold at 14 DAS. In addition, HPLC analysis revealed that the contents of ferulic and p‐coumaric acids increased by 6·3 and 4·6 times, respectively, at 14 DAS. Amount of gallic acid was also little more than double. Lignin deposition in sunflower root increased by 2·7, 3·4 and 3·7 times through combined application of T‐1055 at 16, 18 and 20 DAS, respectively. Combined application also increased the accumulation of PR‐2 and PR‐3 proteins by 3·3 and 3·9 times, respectively, at 12 DAS in followed by seed treatment alone. CONCLUSIONS: The combined application of T‐1055 triggered defence responses in an enhanced level in sunflower than the soil and seed alone and provided better protection against Rhizoctonia seedling blight. SIGNIFICANCE AND IMPACT OF THE STUDY: Rhizospheric fungal bioagent ‘T‐1055’ can enhance protection in sunflower against the R. solani pathogen through augmented elicitation of host defence responses.
Nanotechnology is a new and emerging technology with wealth of applications. It involves the synthesis and application of materials having one of the dimensions in the range of 1–100 nm. A wide ...variety of physico–chemical approaches are being used these days for the synthesis of nanoparticles (NPs). However, biogenic reduction of metal precursors to produce corresponding NPs is eco-friendly, less expensive, free of chemical contaminants for medical and biological applications where purity of NPs is of major concern. Biogenic reduction is a “Bottom Up” approach similar to chemical reduction where a reducing agent is replaced by extract of a natural products with inherent stabilizing, growth terminating and capping properties. Furthermore, the nature of biological entities in different concentrations in combination with reducing organic agents influence the size and shape of NPs. Present review focuses on microbes or plants based green synthesis of Ag, Au, Cu, Fe, Pd, Ru, PbS, CdS, CuO, CeO₂, Fe₃O₄, TiO₂, and ZnO NPs and their potential applications.
The aqueous extract of leaf (LE), fruit (FE) and seed (SE) of Moringa oleifera was assessed to examine the ability to inhibit the oxidative DNA damage, antioxidant and anti-quorum sensing (QS) ...potentials. It was found that these extracts could significantly inhibit the OH-dependent damage of pUC18 plasmid DNA and also inhibit synergistically with trolox, with an activity sequence of LE>FE>SE. HPLC and MS/MS analysis was carried out, which showed the presence of gallic acid, chlorogenic acid, ellagic acid, ferulic acid, kaempferol, quercetin and vanillin. The LE was with comparatively higher total phenolics content (105.04mg gallic acid equivalents (GAE)/g), total flavonoids content (31.28mg quercetin equivalents (QE)/g), and ascorbic acid content (106.95mg/100g) and showed better antioxidant activity (85.77%), anti-radical power (74.3), reducing power (1.1 ascorbic acid equivalents (ASE)/ml), inhibition of lipid peroxidation, protein oxidation, OH-induced deoxyribose degradation, and scavenging power of superoxide anion and nitric oxide radicals than did the FE, SE and standard α-tocopherol. Eventually, LE and FE were found to inhibit violacein production, a QS-regulated behavior in Chromobacterium violaceum 12472.
The antioxidant and anti-quorum sensing activities of eight extracts were studied in green pods of
Acacia nilotica. The specific phenolic compositions and their quantifications were performed by HPLC ...and MS/MS, which showed that the HEF (pH 4) was higher in gallic acid, ellagic acid, epicatechin, rutin, and GTs. In order to find antioxidant potential of various extracts, their activities were studied for TPC, AOA, FRSA, RP, inhibition of LPO, FIC activity, HO
and
O
2
-
scavenging activities. Among them HEF (pH 4) has shown potent antioxidant activity. HEF (pH 4) was also found effective in protecting plasmid DNA and HAS protein oxidation induced by HO
. Pre-treatment of HEF (pH 4) at 75 and 150
mg/kg body weight for 6 days caused a significant increase in the levels of CAT and SOD and decrease in the level of MDA content in liver, lungs, kidneys and blood when compared to CCl
4-intoxicated rats. Eventually, the extracts were also screened for anti-QS activity. Of these extracts two showed QS inhibition: HEF (pH 4) and HCE. The results obtained strongly indicate that green pod of
A. nilotica are important source of natural antioxidants.
The present study is focused on the extracellular synthesis of silver nanoparticles (AgNPs) using culture supernatant of an agriculturally important bacterium, Serratia sp. BHU-S4 and demonstrates ...its effective application for the management of spot blotch disease in wheat. The biosynthesis of AgNPs by Serratia sp. BHU-S4 (denoted as bsAgNPs) was monitored by UV-visible spectrum that showed the surface plasmon resonance (SPR) peak at 410 nm, an important characteristic of AgNPs. Furthermore, the structural, morphological, elemental, functional and thermal characterization of bsAgNPs was carried out using the X-ray diffraction (XRD), electron and atomic microscopies, energy dispersive X-ray (EDAX) spectrometer, FTIR spectroscopy and thermogravimetric analyzer (TGA), respectively. The bsAgNPs were spherical in shape with size range of ∼10 to 20 nm. The XRD and EDAX analysis confirmed successful biosynthesis and crystalline nature of AgNPs. The bsAgNPs exhibited strong antifungal activity against Bipolaris sorokiniana, the spot blotch pathogen of wheat. Interestingly, 2, 4 and 10 µg/ml concentrations of bsAgNPs accounted for complete inhibition of conidial germination, whereas in the absence of bsAgNPs, conidial germination was 100%. A detached leaf bioassay revealed prominent conidial germination on wheat leaves infected with B. sorokiniana conidial suspension alone, while the germination of conidia was totally inhibited when the leaves were treated with bsAgNPs. The results were further authenticated under green house conditions, where application of bsAgNPs significantly reduced B. sorokiniana infection in wheat plants. Histochemical staining revealed a significant role of bsAgNPs treatment in inducing lignin deposition in vascular bundles. In summary, our findings represent the efficient application of bsAgNPs in plant disease management, indicating the exciting possibilities of nanofungicide employing agriculturally important bacteria.
Biochar carbon stability in four contrasting soils Fang, Y; Singh, B; Singh, B. P ...
European journal of soil science,
2014, 2014-01, January 2014, 2014-01-00, 20140101, Volume:
65, Issue:
1
Journal Article
Peer reviewed
There is a limited understanding of the effects of soil properties on biochar carbon (C) stability. This knowledge is essential to evaluate the capacity of biochar for long‐term soil C sequestration ...fully. In this study two biochars, produced by slow pyrolysis at 450 or 550°C from a δ¹³C‐depleted (−36.4‰) Eucalyptus saligna Sm. woody material, were incubated in four soils (Inceptisol, Entisol, Oxisol and Vertisol) of contrasting chemical and mineralogical properties. The total biochar‐C mineralized over 12 months was 0.30–1.14 and 0.97–2.71% from the soil‐biochar mixtures incubated at 20 and 40°C, respectively. The total biochar‐C mineralized (mg CO₂‐C per unit of native soil organic C (SOC) basis) from soils incubated with the 450°C biochar was approximately twice the corresponding amount mineralized from the 550°C biochar systems. The influence of soil properties on biochar‐C mineralization was greater for the 450°C biochar than the 550°C biochar. The smallest proportion of C mineralized from the 450°C biochar occurred in the Inceptisol incubated at 20°C and in the Oxisol at 40°C. However, when expressed on a per unit of native SOC basis, the C mineralization of the 450 and 550°C biochars was least in the Oxisol and greatest in the Inceptisol at both incubation temperatures. Mean residence times (MRTs) of the biochars estimated using the two‐pool exponential model varied between 44 and 610 years. The estimated MRT of the biochars may vary under field conditions depending upon the environmental conditions and addition of labile C from plants. Our results indicate that biochar‐C was stabilized by variable charge minerals in the Oxisol and that the stabilization occurred rapidly at high temperatures.
Over the past decade, incorporation of nanomaterials into agricultural practices like nanofertilizers and nanopesticides has gained a lot of attention. Progress and application of fertilizers in ...nanoforms are one of the effective options for considerable improvement of the agricultural yield worldwide. Zinc oxide nanoparticles (ZnO NPs) are considered as a biosafe material for biological species. Earlier studies have shown the potential of ZnO NPs in stimulation of seed germination and plant growth as well as disease suppression and plant protection by its antimicrobial activity. However, both positive and negative effects of ZnO NPs on plant growth and metabolism at various developmental periods have been documented. Uptake, translocation and accumulation of ZnO NPs by plants depend upon the features of NPs as well as the anatomy of the host plant. This review summarizes the applications of ZnO NPs as nanofertilizer in crop production and also attempts to examine and record the possible mechanism of antimicrobial activity of ZnO NPs. Biological synthesis of ZnO NPs and their uptake, translocation and biotransformation in plants via various routes have also been examined.
A newly hybrid nature inspired algorithm called HPSOGWO is presented with the combination of Particle Swarm Optimization (PSO) and Grey Wolf Optimizer (GWO). The main idea is to improve the ability ...of exploitation in Particle Swarm Optimization with the ability of exploration in Grey Wolf Optimizer to produce both variants’ strength. Some unimodal, multimodal, and fixed-dimension multimodal test functions are used to check the solution quality and performance of HPSOGWO variant. The numerical and statistical solutions show that the hybrid variant outperforms significantly the PSO and GWO variants in terms of solution quality, solution stability, convergence speed, and ability to find the global optimum.
Aims
To study the biocontrol potential of nematode‐trapping fungus Arthrobotrys oligospora in protecting tomato (Lycopersicon esculentum Mill.) against Meloidogyne incognita and Rhizoctonia solani ...under greenhouse and field conditions.
Methods and Results
Five isolates of the nematode‐trapping fungus Arthrobotrys oligospora isolated from different parts of India were tested against Meloidogyne incognita and Rhizoctonia solani in tomato (Lycopersicon esculentum Mill.) plants grown under greenhouse and field conditions. Arthrobotrys oligospora‐treated plants showed enhanced growth in terms of shoot and root length and biomass, chlorophyll and total phenolic content and high phenylalanine ammonia lyase activity in comparison with M. incognita‐ and R. solani‐inoculated plants. Biochemical profiling when correlated with disease severity and intensity in A. oligospora‐treated and untreated plants indicate that A. oligospora VNS‐1 offered significant disease reduction in terms of number of root galls, seedling mortality, lesion length, disease index, better plant growth and fruit yield as compared to M. incognita‐ and R. solani‐challenged plants.
Conclusion
The result established that A. oligospora VNS‐1 has the potential to provide bioprotection agents against M. incognita and R. solani.
Significance and Impact of the Study
Arthrobotrys oligospora can be a better environment friendly option and can be incorporated in the integrated disease management module of crop protection. Application of A. oligospora not only helps in the control of nematodes but also increases plant growth and enhances nutritional value of tomato fruits. Thus, it proves to be an excellent biocontrol as well as plant growth promoting agent.
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