scholarly journals Bukhuldaria vietnamensis mediated induced wilt resistance in chickpea

2018 ◽  
Vol 33 (01) ◽  
Author(s):  
Palak P. Mistry ◽  
K. P. Suthar ◽  
Diwakar Singh ◽  
M. D. Khunt
Keyword(s):  
Time Course ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Tolerance Mechanism ◽  
Enhanced Production ◽  
Treatment Conditions ◽  
Ros Enzymes ◽  
Pre Treatment ◽  
Root Tissues

The efficacy of root dipping with Bukhuldaria vietnamensis isolate KM2 (Bv-KM2) an antagonist of Fusarium oxysporum was evaluated to improve the tolerance mechanism of chickpea against wilt. The increase in activity of key ROS enzymes of root tissues viz., peroxidase, catalase and superoxide dismutase was reported with the increase in time course of infection in resistance and susceptible varieties at 1 and 5 DAI. The pre-treatment with Bv-KM2 helps to maintain the higher level of ROS enzymes in susceptible variety JG-62, hence imparts resistance against Foc stress. In resistant variety WR-315 it further improves resistance towards Foc stress through enhanced production of ROS enzymes. The role of phenolic compounds and polyamines was studied from root tissues using HPTLC at 5 DAI. Among the polyphenols, ferulic acid was found to be constitutively expressing in both varieties over the treatment condition, the salicylic acid was found in resistant variety WR-315 over the treatment whereas it was found to be induced in susceptible variety JG-62. Four polyamines were detected through HPTLC of which two were unidentified where as two were identified as cadvarine and spermine. One of unidentified polyamiens (P2) was reported only in resistant variety WR-315 under different treatment conditions. Overall the Bv-KM2 treatment leads to alteration in ROS enzymes, polyphenols and polyamines which result in improved tolerance to Foc in both resistant and susceptible varieties.

scholarly journals CsPrx25, a class III peroxidase in Citrus sinensis, confers resistance to citrus bacterial canker through the maintenance of ROS homeostasis and cell wall lignification

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Qiang Li ◽  
Xiujuan Qin ◽  
Jingjing Qi ◽  
Wanfu Dou ◽  
Christophe Dunand ◽  
...  
Keyword(s):  
Cell Wall ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Bacterial Canker ◽  
Class Iii ◽  
Ros Homeostasis ◽  
Citrus Production ◽  
Citrus Bacterial Canker ◽  
Apoplastic Barrier

AbstractCitrus bacterial canker (CBC) results from Xanthomonas citri subsp. citri (Xcc) infection and poses a grave threat to citrus production. Class III peroxidases (CIII Prxs) are key proteins to the environmental adaptation of citrus plants to a range of exogenous pathogens, but the role of CIII Prxs during plant resistance to CBC is poorly defined. Herein, we explored the role of CsPrx25 and its contribution to plant defenses in molecular detail. Based on the expression analysis, CsPrx25 was identified as an apoplast-localized protein that is differentially regulated by Xcc infection, salicylic acid, and methyl jasmone acid in the CBC-susceptible variety Wanjincheng (C. sinensis) and the CBC-resistant variety Calamondin (C. madurensis). Transgenic Wanjincheng plants overexpressing CsPrx25 were generated, and these transgenic plants exhibited significantly increased CBC resistance compared with the WT plants. In addition, the CsPrx25-overexpressing plants displayed altered reactive oxygen species (ROS) homeostasis accompanied by enhanced H2O2 levels, which led to stronger hypersensitivity responses during Xcc infection. Moreover, the overexpression of CsPrx25 enhanced lignification as an apoplastic barrier for Xcc infection. Taken together, the results highlight how CsPrx25-mediated ROS homeostasis reconstruction and cell wall lignification can enhance the resistance of sweet orange to CBC.

scholarly journals Catalytic activity of nanosized Au/CeO2 catalyst towards H2O2 decomposition and the role of cationic/metallic ratio in its activity

2019 ◽  
Vol 10 (4) ◽  
pp. 317-322
Author(s):  
Ayman Abd El-Moemen
Keyword(s):  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Catalytic Decomposition ◽  
Metallic Gold ◽  
Kinetic Measurements ◽  
H2o2 Decomposition ◽  
Treatment Conditions ◽  
Treated Sample ◽  
Pre Treatment

The catalytic decomposition of H2O2 on differently pre-treated Au/CeO2 catalyst was studied by kinetic measurements at 20-50 °C. The prepared catalyst was subjected to pre-treatment by heating either in oxidative (10% O2/N2) or inert (pure N2)atmosphere at 400 °C. The different oxidation states of gold were determined by X-ray photoelectron spectroscopy measurements. The Au/CeO2 catalyst exhibited an excellent catalytic activity towards H2O2 decomposition. The catalytic activity of oxygen pre-treated sample was about twice higher than that measured for nitrogen pre-treated sample. This finding ran parallel to the amount of Aun+ as determined by XPS, indicating the role played by Aun+ species as the most active catalyst’s constituent. However, one cannot overlook the role of metallic gold in catalyzing the H2O2, decomposition showing small activity compared to that of cationic gold. The average crystallites size of metallic gold particles was found to be 7±0.5 nm independent of the pre-treatment conditions. The apparent activation energy of the catalyzed reaction was found to be 46.5 and 47.8 kJ/mol for oxygen and nitrogen pre-treatment, respectively.

Production of phytotoxic substances by Alternaria triticina

1979 ◽  
Vol 57 (11) ◽  
pp. 1255-1258 ◽  
Author(s):  
C. S. K. Vijaya Kumar ◽  
A. S. Rao
Keyword(s):  
Thin Layer ◽  
Culture Filtrate ◽  
Chromatographic Analysis ◽  
Root Elongation ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Toxic Metabolites ◽  
Thin Layer Chromatographic Analysis ◽  
Phytotoxic Compound

The culture filtrate of Alternaria triticina Prasada & Prabhu inhibited germination and root elongation of seeds of a resistant variety (HD 1982) and a susceptible variety (Kalyan Sona) of wheat. The filtrate-induced symptoms on the leaves of wheat plants were similar to those induced by the fungus. Thin-layer chromatographic analysis of the crude toxin extracted in n-butanol, acetone, and petroleum ether revealed the presence of more than one phytotoxic compound in the culture filtrate of A. triticina. The toxic principles were thermostable and nonspecific and inhibited the growth of wheat. The possible role of toxic metabolites during pathogenesis is suggested.

scholarly journals MEKANISME KETAHANAN KENTANG (SOLANUM TUBEROSUM) TERHADAP NEMATODA SISTA KUNING (GLOBODERA ROSTOCHIENSIS)

2009 ◽  
Vol 9 (1) ◽  
pp. 46-53
Author(s):  
Dewi Fitriyanti ◽  
Mulyadi Mulyadi ◽  
Christanti Christanti
Keyword(s):  
Solanum Tuberosum ◽  
Chlorogenic Acid ◽  
Caffeic Acid ◽  
Resistance Mechanism ◽  
Susceptible Variety ◽  
Globodera Rostochiensis ◽  
Resistant Variety ◽  
Potato Varieties ◽  
Moderately Resistant

Resistance mechanism of potato (Solanum tuberosum) to golden cyst nematode (Globodera rostochiensis).  The research was conducted from June 2005 to May 2006 in Kepuhharjo, Cangkringan, Sleman, Yogyakarta. The aims of the research were to find the resistance status of 20 potato varieties, role of  chlorogenic acid and caffeic acid  in the resistance mechanism and histopathological differences between resistant and susceptible potato varieties to  G. rostochiensis. The results showed that two varieties were resistant to G. rostochiensis, i.e, Hertha and Manohara.  Thirteen varieties were moderately resistant, i.e; No.30, No.44, No. 5, No.19, Batang Hitam, Agria,  Desiree, Berolina, Atlantik, No.095, Cipanas, FLS and Colombus, and five varieties were susceptible, i.e; Kikondo, Granola, Erika, LBR, and Fries. The presence of chlorogenic acid and caffeic acid in Hertha (resistant variety) and in Granola (susceptible variety) were analized by TLC. In Hertha chlorogenic acid was detected at 4, 5, and 6 days after inoculation (DAI), whereas in Granola it was detected at 1 and 6 DAI. It was assumed that the presence of chlorogenic acid for 3 successively week in Hertha, caused it more resistant than Granola.  Cell lignification inhibited                       G. rostochiensis grow well inside the root tissue of Hertha, whereas in Granola only a few cell was lignified as indicated by less absorption of red colour (safranin) in infected areas. Caffeic acid was not detected either in uninoculated or inoculated of both potato varieties.  It indicated that caffeic acid might not be naturally present in Hertha and Granola and nematode infection could not stimulate the production of this compound.

Activation of cytochrome c to a peroxidase compound I-type intermediate by H2O2: relevance to redox signalling in apoptosis

2004 ◽  
Vol 71 ◽  
pp. 97-106 ◽  
Author(s):  
Mark Burkitt ◽  
Clare Jones ◽  
Andrew Lawrence ◽  
Peter Wardman
Keyword(s):  
Cytochrome C ◽  
Hydroxyl Radical ◽  
Redox Regulation ◽  
Chemotherapeutic Agents ◽  
Tyrosyl Radical ◽  
Compound I ◽  
Definitive Evidence ◽  
Enhanced Production ◽  
Physico Chemical

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.

Collagen-Induced Platelet Aggregation: -Evidence Against the Essential Role of Platelet Adenosine Diphosphate

1979 ◽  
Vol 42 (04) ◽  
pp. 1193-1206 ◽  
Author(s):  
Barbara Nunn
Keyword(s):  
Platelet Aggregation ◽  
Time Course ◽  
Essential Role ◽  
Atp Release ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
High Doses ◽  
Induced Aggregation

SummaryThe hypothesis that platelet ADP is responsible for collagen-induced aggregation has been re-examined. It was found that the concentration of ADP obtaining in human PRP at the onset of aggregation was not sufficient to account for that aggregation. Furthermore, the time-course of collagen-induced release in human PRP was the same as that in sheep PRP where ADP does not cause release. These findings are not consistent with claims that ADP alone perpetuates a collagen-initiated release-aggregation-release sequence. The effects of high doses of collagen, which released 4-5 μM ADP, were not inhibited by 500 pM adenosine, a concentration that greatly reduced the effect of 300 μM ADP. Collagen caused aggregation in ADP-refractory PRP and in platelet suspensions unresponsive to 1 mM ADP. Thus human platelets can aggregate in response to collagen under circumstances in which they cannot respond to ADP. Apyrase inhibited aggregation and ATP release in platelet suspensions but not in human PRP. Evidence is presented that the means currently used to examine the role of ADP in aggregation require investigation.

scholarly journals Membrane condenser as emerging technology for water recovery and gas pre-treatment: current status and perspectives

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Adele Brunetti ◽  
Francesca Macedonio ◽  
Giuseppe Barbieri ◽  
Enrico Drioli
Keyword(s):  
Current Status ◽  
Innovative Technology ◽  
Water Recovery ◽  
Treatment Unit ◽  
Treatment Stage ◽  
Treatment Technologies ◽  
Pre Treatment ◽  
And Control

Abstract The recent roadmap of SPIRE initiative includes the development of “new separation, extraction and pre-treatment technologies” as one of the “key actions” for boosting sustainability, enhancing the availability and quality of existing resources. Membrane condenser is an innovative technology that was recently investigated for the recovery of water vapor for waste gaseous streams, such as flue gas, biogas, cooling tower plumes, etc. Recently, it has been also proposed as pre-treatment unit for the reduction and control of contaminants in waste gaseous streams (SOx and NOx, VOCs, H2S, NH3, siloxanes, halides, particulates, organic pollutants). This perspective article reports recent progresses in the applications of the membrane condenser in the treatment of various gaseous streams for water recovery and contaminant control. After an overview of the operating principle, the membranes used, and the main results achieved, the work also proposes the role of this technology as pre-treatment stage to other separation technologies. The potentialities of the technology are also discussed aspiring to pave the way towards the development of an innovative technology where membrane condenser can cover a key role in redesigning the whole upgrading process.

scholarly journals Enhanced Production of the Mical Redox Domain for Enzymology and F-actin Disassembly Assays

2021 ◽  
Vol 22 (4) ◽  
pp. 1991
Author(s):  
Jimok Yoon ◽  
Heng Wu ◽  
Ruei-Jiun Hung ◽  
Jonathan R. Terman
Keyword(s):  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Actin Dynamics ◽  
Specific Substrate ◽  
Actin Assembly ◽  
Redox Enzymes ◽  
Enhanced Production ◽  
Reversible Redox ◽  
Future Work ◽  
Signaling Process

To change their behaviors, cells require actin proteins to assemble together into long polymers/filaments—and so a critical goal is to understand the factors that control this actin filament (F-actin) assembly and stability. We have identified a family of unusual actin regulators, the MICALs, which are flavoprotein monooxygenase/hydroxylase enzymes that associate with flavin adenine dinucleotide (FAD) and use the co-enzyme nicotinamide adenine dinucleotide phosphate (NADPH) in Redox reactions. F-actin is a specific substrate for these MICAL Redox enzymes, which oxidize specific amino acids within actin to destabilize actin filaments. Furthermore, this MICAL-catalyzed reaction is reversed by another family of Redox enzymes (SelR/MsrB enzymes)—thereby revealing a reversible Redox signaling process and biochemical mechanism regulating actin dynamics. Interestingly, in addition to the MICALs’ Redox enzymatic portion through which MICALs covalently modify and affect actin, MICALs have multiple other domains. Less is known about the roles of these other MICAL domains. Here we provide approaches for obtaining high levels of recombinant protein for the Redox only portion of Mical and demonstrate its catalytic and F-actin disassembly activity. These results provide a ground state for future work aimed at defining the role of the other domains of Mical — including characterizing their effects on Mical’s Redox enzymatic and F-actin disassembly activity.

scholarly journals Enhanced production of Clavulanic acid by improving glycerol utilization using reporter-guided mutagenesis of an industrial Streptomyces clavuligerus strain

2021 ◽  
Author(s):  
Chang-Hun Shin ◽  
Hang Soo Cho ◽  
Hyung-Jin Won ◽  
Ho Jeong Kwon ◽  
Chan-Wha Kim ◽  
...  
Keyword(s):  
Clavulanic Acid ◽  
Wild Type Strain ◽  
Random Mutagenesis ◽  
Streptomyces Clavuligerus ◽  
Wild Type ◽  
Mutant Selection ◽  
Enhanced Production ◽  
Industrial Strains ◽  
Glycerol Utilization

Abstract Clavulanic acid (CA) produced by Streptomyces clavuligerus is a clinically important β-lactamase inhibitor. It is known that glycerol utilization can significantly improve cell growth and CA production of S. clavuligerus. We found that the industrial CA-producing S. clavuligerus strain OR generated by random mutagenesis consumes less glycerol than the wild-type strain; we then developed a mutant strain in which the glycerol utilization operon is overexpressed, as compared to the parent OR strain, through iterative random mutagenesis and reporter-guided selection. The CA production of the resulting S. clavuligerus ORUN strain was increased by approximately 31.3 per cent (5.21 ± 0.26 g/L) in a flask culture and 17.4 per cent (6.11 ± 0.36 g/L) in a fermenter culture, as compared to that of the starting OR strain. These results confirmed the important role of glycerol utilization in CA production and demonstrated that reporter-guided mutant selection is an efficient method for further improvement of randomly mutagenized industrial strains.

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