Chromium (Cr) contamination in soil is a growing concern in sustainable agricultural production and food safety. Remediation of Cr from contaminated soils is a challenging task which may not only ...help in sustaining agriculture but also in minimizing adverse environmental impacts. Pot culture experiments were performed with the application of varied concentration of Cr+6 to assess the Chromium accumulation potential of Lemongrass and to study the impact of toxic concentration of Cr+6 on morphological, physiological and biochemical parameters of the plant. The results showed an increasing accumulation trend of Chromium with increasing Chromium concentrations in both root and shoot of 60 days old Lemongrass plants, while the protein and chlorophyll contents decreased. Similarly, accumulation of Cr increased the levels of proline and antioxidant enzymes indicating the enhanced damage control activity. The potentiality of the plant with the capacity to accumulate and stabilize Cr compound in Cr contaminated soil by phytoremediation process has been explored in the present investigation.
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•The degree of toxicity using varying concentrations of Cr+6 on growing Lemongrass.•Phytoaccumulation ability of Lemongrass with reference to tolerance indices.•Severity of Chromium toxicity stress on morphological, physiological and biochemical lesions.•Chromium bioavailability in plants.
Surface modification of natural fibres by gamma irradiation is an economical and potent technique. The biodegradability of gamma irradiated Luffa cylindrica (LC) fibres having response of doses ...(0.5Gy, 1Gy and 2Gy) is studied. The degradation process is carried out in various environments like compost, sand, soil, salt water, brackish water and sweet water for a period of 90 days and microbial degradation using bacteria and fungi for a period of 90 days. The rate of biodegradation was calculated by measuring the loss of weight of composites at an interval of 30 days in each environmental condition. Preliminary results reported that the bacterial environment was the most prominent medium for degradation than fungi. B8 composites showed degradation of 27.5% and 3.59 in bacterial and fungal medium respectively. A minimum degradation was observed in compost medium (0.29%, 2.52%, 0.21%, 0.08%, 0.11%, 0.13%, 0.17%, 1.25% and 1.51% for B1–B9 respectively). For exploring the use of the composites in the field of biomedical sciences, the LC fibres are modified using calcium salts before reinforcement. The thermal properties like crystallization temperature (Tcc), glass transition temperature (Tg), melting peak temperature (Tm) and thermal stability of the bio-composites were analyzed using Differential scanning calorimetry (DSC) in temperature range from 30 °C to 250 °C and the thermogravimetric analysis (TGA) was done in the temperature range of 20 °C to 700 °C. With increase in irradiation dose, crystallization temperature and glass transition temperature increased. Increasing in the irradiation dose, thermal stability of the composites decreased.
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•Surface modification of natural fibers by gamma irradiation is an economical and potent technique in mitigating environmental issues.•The degradation process is carried out in various environments like compost, sand, soil, salt water, brackish water, sweet water and microbial degradation using bacteria and fungi for a period of 90 days.•Preliminary results reported that the bacterial environment was the most prominent medium for degradation than fungi. B8 composites showed degradation of 27.5% and 3.59 in bacterial and fungal medium respectively.•The developed composites can be implemented in the sectors like biomedical engineering, drug designing and delivery, textile industries and many more.
The experiment was designed to evaluate the roles of Rhizophagus irregularis on chlorophyll fluorescence and chromium bioaccumulation in a grass species (Brachiaria mutica) by supplementing Cr+6 at ...different concentrations. Arbuscular Mycorrhizal Fungi (AMF) association facilitated lessening of chromium level in contaminated soil and enhanced chromium bioavailability in Brachiaria mutica. The mycorrhizal inoculated increased the chlorophyll (0.925 mg/g), carotenoid (0.127 mg/g), protein (2.883 mg/g), proline (0.889 mg/g) contents and activities of antioxidant enzymes like catalase, ascorbate peroxidase and glutathione peroxidase. The mycorrhizal inoculated plants also showed enhanced overall photosynthetic performance (PIϕ = 2.473) and enhanced PS–II to PS–I electron transport as evident from yield parameter (0.712) and TR0/RC (2.419) for 60 mg/kg Cr+6 treatment. The observations suggest that AMF association could defend the plants from chromium stress by elevating the number of antioxidants in plants. Rhizophagus irregularis was found to maintain a successful symbiotic relationship with Brachiaria mutica in chromium contaminated soil. The observations recommended that Rhizophagus irregularis in association with Brachiaria mutica would be an innovative approach for decontamination of Cr+6.
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•Arbuscular Mycorrhizal Fungi (AMF) induced phytoremediation efficiency and tolerance capacity of Brachiaria mutica to hexavalent chromium (Cr+6) toxicity.•AMF association possibly defends the plants from oxidative stress induced by hexavalent chromium by altering the metabolic processes of the plant.•AMF enhanced the tolerance index, bioconcentration factor and transportation index of Brachiaria mutica.•AM fungi enhanced the photosynthetic performance and quantum yield in B. mutica under Cr+6 stress.
Rice serves as a source of livelihood to millions of people as staple food. Stem rot of rice caused by Sclerotium oryzae has been an agriculturally significant disease cause about 35% of crop loss. ...This review dealt with stem rot management strategies applying various agronomic practices. Control of stem rot using fungicide leads to environmental hazour along with its residual effect on human health. Thus, biocontrol using Trichoderma is an alternative cost effective method. Utilization of resistant wild rice genotypes like Oryza rufipogon, O. spontanea and O. nivara opens scope for safe transmission of the heritable trait through breeding. Plant immunisation by undderstanding pathogen associated molecular patterns (PAMPs), molecular interaction between the elicitors and the corresponding plant receptor protein, R-gene-dependent resistance, host specific resistance by defense signaling through conserve nucleotide-binding and leucine-rich repeat domains are discussed. Early defense response (EDR), role of ROS, anti-oxidant enzymes, plant specific phytoalexin synthesis, release of defense signaling molecules, activation of different signaling pathways are also presented on plant defiance strategy. Activation of MAPKs, npr1 gene regulation, abundant expression of transcript factors (TF) genes, anti-microbial PR protein release, systemic acquired resistance by metal ions induced proteins may be utilized applying biotechnological tools for acquiring stem rot resistance in rice.
•This review dealt with stem rot management of rice caused by Sclerotium oryzae and molecular mechanism of disease resistance.•Synthetic elicitors and low dose cadmium induced proteins (~43 kDa or ~47 kDa) are important precursor imparting resistance.•Receptor protein interactions, R-gene expression and defense signaling through conserve nucleotide-binding are discussed.•Role of ROS, anti-oxidants, phytoalexin synthesis, activation of signaling pathways as defence response are presented.•Transfer of MAPKs, npr1 and metal induced gens into the sensitive varieties in developing stem tor resistant rice is safer.
The growing prevalence of polymer-based plastics in the environment is an imminent risk to the natural world. As an immediate consequence of this, extensive research has been launched over the course ...of the past few decades in an effort to reduce the damage that manmade plastics cause to the natural environment. The current study attempts to explore the biodegradability of polylactic acid (PLA), a bio-compatible plastic, by incorporating small amount of electron beam irradiated natural fibers (2 to 10%) derived from luffa cylindrica (LC) at varying irradiation doses (0.5 Gy, 1 Gy, and 2 Gy). Natural fiber surface treatment using electron beam irradiation is effective and environmentally friendly. The biodegradation of composites was studied for 90 days in sand, soil, compost, brackish water, fresh water, salt water, and bacterial and fungal conditions. Maximum decomposition was observed in the composite sample (PLA/10% wt of LC fiber at 2.0 Gy) at 15.42% and 4.73% in bacterial and soil environments. X-ray diffraction (XRD) and Raman spectroscopy validated the fiber and PLAs crystallinity and molecular interaction. The derivative thermo-gravimetric curve (DTGA) showed that electron beam irradiation removed moisture, hemicelluloses, and lignin from hydrophilic fibers. The incorporation of LC fibers into the bio-composites resulted in an increase in the glass transition temperature (
T
g
), melting temperature (
T
m
), and crystallization temperature (
T
c
). Additionally, after LC fiber reinforcement, the composites’ dielectric properties were enhanced.
Graphical Abstract
Macrotyloma uniflorum (horse gram) is considered an under-utilized legume crop despite its nutritional and medicinal values. In India, it has wide acceptance among farming communities. This ...investigation emphasized on the possible application of two endosymbionts (Bacillus sp. AS03 and Rhizobium sp. AS05) of horse gram cultivated on Cr (VI)-contaminated soil. The photosynthetic performance (PIφ) of Cr treated plants co-inoculated with AS03 and AS05 was significantly improved compared with non-inoculated Cr treated plants based on photosynthetic yield, which was evidenced from the rise in the fluorescence at I–P transient and rate of photosynthesis (pN), indicating synergistic action between plant and bacteria (AS03 and AS05). The smooth electron transport from PS II to PS I was achieved in the Cr stressed plants inoculated with both the bacterial strains. The detrimental effects of Cr toxicity on the root tips were also minimized with bioinoculation as revealed from mitotic index. Plants with dual inoculation of AS03 and AS05 had significantly lesser chromosomal aberration in the roots. Dual inoculation biochar or seed inoculation have beneficial impact on the plant photosynthetic performance along with improved growth of roots in plants treated with Cr (VI). The results of the current work suggest the possitive effect of dual inoculation of Cr tolerant endosymbionts, Bacillus sp. (AS03) and nodulating Rhizobium sp. (AS05), in reducing cytological as well as physiological stress of plants in Cr (VI) contaminated soil.
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•Endosymbiotic Bacteria drops Abnormality Index in Macrotyloma under Cr (IV) stress.•Dual inoculation increased photosynthetic performance of Macrotyloma.•Chlorophyll fluorescence parameters showed synergistic effect of dual inoculation.
Pot experiments were conducted for 60 days to investigate the phytoremediation potential of Cassia tora grown in different concentrations of chromium (Cr) rich overburden soil (OBS) of Sukinda ...Chromite Mine (10, 20, 30, 40, 50, 70, and 100%). To assess the phytoaccumulation ability of C. tora, the tolerance index (TI), bio‐concentration factor (BCF), transportation index (Ti), and total accumulation rate (TAR) were measured. The results showed that at 100% OBS the TI, BCF, Ti, and TAR of C. tora have 23.89, 0.28, 60.25, and 7.46, respectively. The Cr recovery from contaminated soil by C. tora was notable as reported to be 6.25, 11.6, 12.75, 14.2, 17.35, 22.65, and 17.7 mg/kg, respectively. The outcome indicated that C. tora is a potential phytoremediator of Cr from contaminated sites due to its high bioaccumulation activity, high tolerance, and Ti. Therefore, C. tora can be suggested for phytostabilization program to lessen toxic Cr from chromite overburden mining sites.
Mangroves are abundant in bioactive natural substances that fight off pathogenic diseases. Different parts of R. apiculata, an abundant mangrove found in Bhitarkanika National Park, India were ...extracted with methanol and a mixture of solvents methanol/ethanol/chloroform (60 : 20 : 20) to evaluate their antimicrobial properties. The combination solvent extract of bark had the highest zone of inhibition (ZOI) of 18.62 mm against Pseudomonas aeruginosa and a ZOI of 17.41 mm against Streptococcus mitis. Bark extracts had the highest DPPH (43 %) and FRAP (96 %) activities. The combination solvent bark extract of R. apiculata had the highest ZOI of 20.42 mm (lowest MIC of 2.12 μg/ml) against Candida albicans and ZOI of 15.33 mm (MIC of 3.02 μg/mL) against Penicillium chrysogenum. Combination bark extracts of R. apiculata contained flavanols than methanolic extracts. The crude extract of R. apiculata bark made with a mixture of solvents containing more active ingredients could be used in novel drug formulation.
Abstract
Mangroves are abundant in bioactive natural substances that fight off pathogenic diseases. Different parts of
R. apiculata
, an abundant mangrove found in Bhitarkanika National Park, India ...were extracted with methanol and a mixture of solvents methanol/ethanol/chloroform (60 : 20 : 20) to evaluate their antimicrobial properties. The combination solvent extract of bark had the highest zone of inhibition (ZOI) of 18.62 mm against
Pseudomonas aeruginosa
and a ZOI of 17.41 mm against
Streptococcus mitis
. Bark extracts had the highest DPPH (43 %) and FRAP (96 %) activities. The combination solvent bark extract of
R. apiculata
had the highest ZOI of 20.42 mm (lowest MIC of 2.12 μg/ml) against
Candida albicans
and ZOI of 15.33 mm (MIC of 3.02 μg/mL) against
Penicillium chrysogenum
. Combination bark extracts of
R. apiculata
contained flavanols than methanolic extracts. The crude extract of
R. apiculata
bark made with a mixture of solvents containing more active ingredients could be used in novel drug formulation.
Mining activities mobilize the heavy metals into the ecosystem. Metals are accumulated in the ecosystem and then contaminate the food chain. Thus, alleviation of heavy metals from mining locations ...deserves special attention for smooth functioning of ecosystem. Different techniques are available for restoration of contaminated sites but remediation of metals through plants is of better choice to solve the contamination problem. Therefore, identification of species for remediation of toxic metals is significant for restoration of the contaminated areas. The article discusses the phytoremediation potential of the grass family Poaceae. Poaceae have been efficacious for cleansing of contaminated environment since they are easy to cultivate with high biomass, fast growth and tolerant to toxic environment. They are also capable to accumulate high amount of toxic metals in the rhizospheric region and least translocation to the shoot. The phytoremediation efficiency of different members of Poaceae was determined by Transportation index (Ti), Bio-concentration factor (BCF) and Tolerance index (TI). Values of Ti > 1 for plant species are considered as suitable for phytoextraction. Most of the members of grass family like lemongrass the value of Ti showed > 1. Therefore, the grass family Poaceae is recommended for restoration of contaminated lands in a sustainable manner.
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•Restoration of contaminated mining sites is of great challenge in recent era.•Phytoremediation technique is an eco-friendly novel tool for restoration of contaminated sites.•The grass family Poaceae, can be exploited as a potential tool for hyper accumulation of toxic metals.•Extensive fibrous root system of Poaceae is quite useful for phytostabilisation of toxic metals at contaminated sites.
