scholarly journals Title: The Cumulative Dose of AMF and GB is More Effective in The Amelioration of Cr(VI) Toxicity in Sorghum (Sorghum Bicolor L.) Than Individually

Author(s):  
Praveen Kumar

Abstract Industrial and anthropogenic activities are the major source of heavy metal toxicants in agricultural soils. Among, heavy metal toxicants, hexavalent chromium is the most toxic toxicant that negatively affects plant’s metabolic activities and yield. It reduces the plant growth and development by influencing the antioxidant defence system’s activities. In the present experiment, two different soil applied dozes of GB viz. 50 and 100mM, and AMF, both individually and in combination were tested for their capability to ameliorate Cr toxicity in sorghum. The promotive behaviour of these treatments for antioxidant defence system was analysed at vegetative (35 DAS) and grain filling stage (95 DAS) in three varieties of sorghum viz. SSG 59-3, HJ 513 (multi-cut) and HJ 541 (single-cut) under 2 and 4 ppm Cr toxicity. At the same time resultant effects of this behaviour on Cr accumulation, grain yield and indices of oxidative stress was also studied. In this experiment antioxidant defence system includes enzymes viz. SOD, APX, CAT, GR, POD and metabolites viz. glutathione, ascorbate, proline, β-carotene and indices of oxidative stress includes parameters viz. PPO, H2O2 and MDA. The results delineated that Cr accumulation and indices of oxidative stress were increased with increasing concentration of Cr stress in all the varieties at both growth stages. Chromium stress at high concentration (4 ppm), decreased the grain yield (71.69 %) as compared with control. Due to 4 ppm Cr stress, PPO activity, MDA and H2O2 accumulation increased significantly (72.29 %, 73.15 %, 79 % respectively, at 35 DAS and 70.36 %, 74.78 %, 79.83 % respectively, at 95 DAS). GB and AMF individually increased antioxidant activity but in combination, further significantly increased antioxidant defence system’s activity which in turn decreased indices of oxidative stress and reduced the Cr toxicity and increased grain yield of sorghum in all varieties at both the growth stages. However, treatment of 100mM GB with AMF was observed most significant in decreasing oxidative stress and improved antioxidant system’s activities and grain yield as compared with all other treatments at both growth stages in all the varieties. SSG 59-3 cultivar showed lowest chromium content (1.60 and 8.61 ppm), indices of oxidative stress and highest antioxidant system’s activity as compared to HJ 513 followed by HJ 541 variety, at 35 and 95 DAS respectively. Thus, among the varieties SSG 59-3 was found most tolerant as compared to HJ 513 followed by HJ 541 variety. These findings suggest that both GB and AMF, either individually or combined can play a positive role to reduce oxidative stress and increased yield attributes under Cr toxicity in sorghum.

2020 ◽  
Author(s):  
Praveen Kumar

Abstract Background: Chromium is most toxic pollutant that negatively affects plant’s metabolic activities and yield. It reduces plant growth by influencing the antioxidant defense system’s activities. The aim of the present research was to examine the ameliorative capability of exogenous GB and AMF spiked in soil, either individually or in combination against Cr toxicity. The ameliorative effects were studied in terms of Cr uptake, grain yield, antioxidative defense system parameters (viz. enzymes – SOD, APX, CAT, GR, POX and metabolites – proline, glutathione, ascorbate, β-carotene) and indices of oxidative stress parameters (viz. PPO, H2O2, and MDA). Results:The results delineated that Cr uptake and indices of oxidative stress were increased with increasing concentration of Cr stress in all the varieties (HJ 541, HJ513 & SSG 59-3) at both the growth stages (35 & 95 DAS). At higher concentration (4 ppm), Cr stress decreased the grain yield (45-50%) as compared with controls. PPO activity, MDA and H2O2 content increased at both growth stages in all the varieties. However, antioxidative enzymes and metabolite activities increased due to Cr stress but this increase was not sufficient to counteract with ROS generated under Cr stress which was enhanced on the application of AMF and GB either individually or in combination (spiked in soil). It decreased the indices of oxidative stress and ameliorated the Cr toxicity and increased grain yield (65-70%) in all the varieties. Conclusions:Both GB and AMF, improved the plant growth and stress tolerance capacity of the plant. GB at both 50 and 100 mM level, significantly ameliorated Cr (VI) toxicity. However, AMF concomitantly with GB further boost up the amelioration behavior of the plant against Cr toxicity, at both growth stages in all the varieties. The combination of 100 mM GB with 10 g AMF was observed most effective among all the treatments. Among the varieties SSG 59-3 had the lowest chromium uptake, indices of oxidative stress, and highest antioxidative system’s activity as compared to HJ 513 followed by HJ 541 variety. Thus AMF and GB either individually or in combination may be used to maintain plant yield attributes under Cr toxicity.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Praveen Kumar

Abstract Background Chromium is the most toxic pollutant that negatively affects a plant’s metabolic activities and yield. It reduces plant growth by influencing the antioxidant defence system’s activities. In the present study, a completely randomized block design experiment with three plants/pot in three replication was conducted on three varieties of sorghum viz. SSG 59–3, HJ 513 (multi-cut) and HJ 541 (single-cut) for amelioration of chromium toxicity (2 & 4 ppm) by exogenous application of GB (50 & 100 mM) with and without AMF in soil. The ameliorative effects were tested at two growth stages viz. vegetative (35 DAS) and grain filling (95 DAS), in terms of Cr uptake, grain yield, antioxidative defence system parameters (viz. enzymes – SOD, APX, CAT, GR, POX and metabolites – proline, glutathione, ascorbate, β-carotene) and indices of oxidative stress parameters (viz. PPO, H2O2, and MDA). Results The results delineated that Cr uptake and indices of oxidative stress were increased with increasing concentration of Cr stress in all the varieties (HJ 541, HJ513 & SSG 59–3) at both the growth stages (35 & 95 DAS). At higher concentration (4 ppm), Cr stress decreased the grain yield (45–50%) as compared with controls. Polyphenoloxidase activity, MDA and H2O2 content increased at both growth stages in all the varieties. However, antioxidative enzymes and metabolite activities increased due to Cr stress but this increase was not sufficient to counteract with ROS generated under Cr stress which was enhanced on the application of AMF and GB either individually or in combination (spiked in soil). It decreased the indices of oxidative stress and ameliorated the Cr toxicity and increased grain yield (65–70%) in all the varieties. Conclusions Both GB and AMF improved the antioxidative activities and stress tolerance capacity of the plant. Glycine betaine at both 50 and 100 mM level, significantly ameliorated Cr toxicity. However, AMF concomitantly with GB further boosts up the amelioration behaviour of the plant against Cr toxicity, at both growth stages in all the varieties. The combination of 100 mM GB with 10 g AMF was observed most effective among all the treatments. Among the varieties, SSG 59–3 had the lowest chromium uptake, indices of oxidative stress, and highest antioxidative system’s activity as compared to HJ 513 followed by HJ 541 variety. Thus AMF and GB either individually or in combination may be used to maintain plant yield attributes under Cr toxicity.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ana Maria Murta Santi ◽  
Paula Alves Silva ◽  
Isabella Fernandes Martins Santos ◽  
Silvane Maria Fonseca Murta

Abstract Background Superoxide dismutase (SOD), a central component of the antioxidant defence system of most organisms, removes excess superoxide anions by converting them to oxygen and hydrogen peroxide. As iron (Fe) SOD is absent in the human host, this enzyme is a promising molecular target for drug development against trypanosomatids. Results We obtained Leishmania infantum mutant clones with lower FeSOD-A expression and investigated their phenotypes. Our attempts to delete this enzyme-coding gene using three different methodologies (conventional allelic replacement or two different CRISPR/methods) failed, as FeSOD-A gene copies were probably retained by aneuploidy or gene amplification. Promastigote forms of WT and mutant parasites were used in quantitative reverse-transcription polymerase chain reaction (RT-qPCR) and western blot analyses, and these parasite forms were also used to assess drug susceptibility. RT-qPCR and western blot analyses revealed that FeSOD-A transcript and protein levels were lower in FeSOD-A−/−/+L. infantum mutant clones than in the wild-type (WT) parasite. The decrease in FeSOD-A expression in L. infantum did not interfere with the parasite growth or susceptibility to amphotericin B. Surprisingly, FeSOD-A−/−/+L. infantum mutant clones were 1.5- to 2.0-fold more resistant to trivalent antimony and 2.4- to 2.7-fold more resistant to miltefosine. To investigate whether the decrease in FeSOD-A expression was compensated by other enzymes, the transcript levels of five FeSODs and six enzymes from the antioxidant defence system were assessed by RT-qPCR. The transcript level of the enzyme ascorbate peroxidase increased in both the FeSOD-A−/−/+ mutants tested. The FeSOD-A−/−/+ mutant parasites were 1.4- to 1.75-fold less tolerant to oxidative stress generated by menadione. Infection analysis using THP-1 macrophages showed that 72 h post-infection, the number of infected macrophages and their intracellular multiplication rate were lower in the FeSOD-A−/−/+ mutant clones than in the WT parasite. Conclusions The unsuccessful attempts to delete FeSOD-A suggest that this gene is essential in L. infantum. This enzyme plays an important role in the defence against oxidative stress and infectivity in THP-1 macrophages. FeSOD-A-deficient L. infantum parasites deregulate their metabolic pathways related to antimony and miltefosine resistance. Graphic Abstract


2008 ◽  
Vol 28 (2) ◽  
pp. 73-81 ◽  
Author(s):  
Chandramani Pathak ◽  
Yogesh K. Jaiswal ◽  
Manjula Vinayak

Constant generation of ROS (reactive oxygen species) during normal cellular metabolism of an organism is generally balanced by a similar rate of consumption by antioxidants. Imbalance between ROS production and antioxidant defence results in an increased level of ROS, causing oxidative stress, which leads to promotion of malignancy. Queuine is a hyper-modified base analogue of guanine, found at the first anticodon position of the Q-family of tRNAs. These tRNAs are completely modified with respect to queuosine in terminally differentiated somatic cells; however, hypo-modification of Q-tRNAs is closely associated with cell proliferation. Q-tRNA modification is essential for normal development, differentiation and cellular function. Queuine is a nutrient factor for eukaryotes. It is found to promote the cellular antioxidant defence system and inhibit tumorigenesis. The activities of antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase are found to be low in the DLAT (Dalton's lymphoma ascites transplanted) mouse liver compared with normal mouse liver. However, exogenous administration of queuine to the DLAT cancerous mouse improves the activities of antioxidant enzymes. These results suggest that queuine promotes the antioxidant defence system by increasing antioxidant enzyme activities and in turn inhibits oxidative stress and tumorigenesis.


2018 ◽  
Vol 27 (3) ◽  
pp. 967-978
Author(s):  
Imran Ali ◽  
Abdul Wakeel ◽  
Sakila Upreti ◽  
Dongdong Liu ◽  
Azizullah Azizullah ◽  
...  

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