Showing papers by "Vishnu D. Rajput published in 2020"

ZnO and CuO nanoparticles: a threat to soil organisms, plants, and human health.

Abstract: The progressive increase in nanoparticles (NPs) applications and their potential release into the environment because the majority of them end up in the soil without proper care have drawn considerable attention to the public health, which has become an increasingly important area of research. It is required to understand ecological threats of NPs before applications. Once NPs are released into the environment, they are subjected to translocation and go through several modifications, such as bio/geo-transformation which plays a significant role in determination of ultimate fate in the environment. The interaction between plants and NPs is an important aspect of the risk assessment. The plants growing in a contaminated medium may significantly pose a threat to human health via the food chain. Metal oxide NPs ZnO and CuO, the most important NPs, are highly toxic to a wide range of organisms. Exposure and effects of CuO and ZnO NPs on soil biota and human health are critically discussed in this study. The potential benefits and unintentional dangers of NPs to the environment and human health are essential to evaluate and expected to produce less toxic and more degradable NPs to minimize the environmental risk in the future.

The mechanisms of biochar interactions with microorganisms in soil

Abstract: Biochar, a carbonaceous material, is increasingly used in the remediation of the anthropogenically polluted soils and the restoration of their ecological functions. However, the interaction mechanisms among biochar, inorganic and organic soil properties and soil biota are still not very clear. The effect of biochar on soil microorganisms is very diverse. Several mechanisms of these interactions were suggested. However, a well acceptable mechanism of biochar effect on soil microorganisms is still missing. Therefore, efforts were made to examine and proposed a mechanism of the interactions between biochar and microorganisms, as well as existing problems of biochar impacts on main groups of soil enzymes, the composition of the microbiota and the detoxification (heavy metals) and degradation (polycyclic aromatic hydrocarbons) of soil pollutants. The data on the process of biochar colonization by microorganisms and the effect of volatile pyrolysis products released by biochar on the soil microbiota were analysed in detail. The effects of biochar on the physico-chemical properties of soils, the content of mineral nutrients and the response of microbial communities to these changes are also discussed. The information provided here may contribute to the solution of the feasibility, effectiveness and safety of the biochar questions to enhance the soil fertility and to detoxify pollutants in soils.

Characteristics of Leaf Stomata and Their Relationship with Photosynthesis in Saccharum officinarum Under Drought and Silicon Application.

Abstract: Silicon (Si) plays an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticide ...

Anatomical and ultrastructural responses of Hordeum sativum to the soil spiked by copper

Abstract: Effects of Cu toxicity from contaminated soil were analysed in spring barley (Hordeum sativum distichum), a widely cultivated species in South Russia. In this study, H. sativum was planted outdoors in one of the most fertile soils-Haplic Chernozem spiked with high concentration of Cu and examined between the boot and head emergence phase of growth. Copper toxicity was observed to cause slow ontogenetic development of plants, changing their morphometric parameters (shape, size, colour). To the best of our knowledge, the ultrastructural changes in roots, stems and leaves of H. sativum induced by excess Cu were fully characterized for the first time using transmission electron microscopy. The plant roots were the most effected, showing degradation of the epidermis, reduced number of parenchyma cells, as well as a significant decrease in the diameter of the stele and a disruption and modification to its cell structure. The comparative analysis of the ultrastructure of control plants and plants exposed to the toxic effects of Cu has made it possible to reveal significant disruption of the integrity of the cell wall and cytoplasmic membranes in the root with deposition of electron-dense material. The changes in the ultrastructure of the main cytoplasmic organelles-endoplasmic reticulum, mitochondria, chloroplasts and peroxisomes-in the stem and leaves were found. The cellular Cu deposition, anatomical and ultrastructural modifications could mainly account for the primary impact points of metal toxicity. Therefore, this work extends the available knowledge of the mechanisms of the Cu effect tolerance of barley.

Recent Development in Micropropagation Techniques for Rare Plant Species.

Abstract: The current investigation aimed to present an overview of the conservation of biological diversity of rare and endangered plant species. Methods of biodiversity conservation as well as several overview recommendations for the preservation of various rare species have been considered. An overview of the taxa included in the red book has been presented on the example of the Russian Federation. Global and local codes and classifiers of plant rarity were also presented. Future prospects for the conservation of biological diversity and the creation and development of bioresource collections have been considered.

Interactive Role of Silicon and Plant–Rhizobacteria Mitigating Abiotic Stresses: A New Approach for Sustainable Agriculture and Climate Change

Abstract: Abiotic stresses are the major constraints in agricultural crop production across the globe The use of some plant-microbe interactions are established as an environment friendly way of enhancing crop productivity, and improving plant development and tolerance to abiotic stresses by direct or indirect mechanisms Silicon (Si) can also stimulate plant growth and mitigate environmental stresses, and it is not detrimental to plants and is devoid of environmental contamination even if applied in excess quantity In the present review, we elaborate the interactive application of Si and plant growth promoting rhizobacteria (PGPRs) as an ecologically sound practice to increase the plant growth rate in unfavorable situations, in the presence of abiotic stresses Experiments investigating the combined use of Si and PGPRs on plants to cope with abiotic stresses can be helpful in the future for agricultural sustainability

Silicon Supply Improves Leaf Gas Exchange, Antioxidant Defense System and Growth in Saccharum officinarum Responsive to Water Limitation.

Abstract: Silicon (Si) is not categorized as a biologically essential element for plants, yet a great number of scientific reports have shown its significant effects in various crop plants and environmental variables. Plant Si plays biologically active role in plant life cycle, and the significant impact depends on its bioaccumulation in plant tissues or parts. In particular, it has been investigated for its involvement in limited irrigation management. Therefore, this experiment was conducted to examine the effect of Si application in eco-physiological, enzymatic and non-enzymatic activities of sugarcane plants against water stress. Four irrigation levels, i.e., normal (100–95% of soil moisture), 80–75, 55–50, and 35–30% of soil moisture were treated for the sugarcane cultivar GT 42 plants supplied with 0, 100, 200, 300, 400 and 500 mg Si L−1 and exposed for 60 days after Si application. Under stress, reduction in plant length (~26–67%), leaf area-expansion (~7–51%), relative water content (~18–57%), leaf greenness (~12–35%), photosynthetic pigments (~12–67%), physiological responses such as photosynthesis (22–63%), stomatal conductance (~25–61%), and transpiration rate (~32–63%), and biomass production were observed in the plants without Si application. The drought condition also inhibited the activities of antioxidant enzymes like catalase (~10–52%), peroxidase (ca. 4–35), superoxide dismutase (10–44%) and enhanced proline (~73–410%), and malondialdehyde content (ca. 15–158%), respectively. However, addition of Si ameliorated drought induced damage in sugarcane plants. The findings suggest that the active involvement of Si in sugarcane responsive to water stress ranges from plant performance and physiological processes, to antioxidant defense systems.

Assessment of phytoremediation capacity of three halophytes: Suaeda monoica, Tamarix indica and Cressa critica.

Abstract: Halophyte is a distinctive group of plants that can survive, even well flourish, at a concentration of Na+ and Cl− ions along with heavy metals that would be lethal to most of the agricultural crop species. These capabilities make certain halophytes good contenders for phytoremediation through phytoextraction or phytostabilization of the salt and heavy metals (HMs) in polluted soils. Thus, the present study elucidates the phytoextraction capacity of three halophytes (Suaeda monoica, Tamarix indica and Cressa critica) growing in saline soil (EC 112 ds m−1), with higher level of HMs rather than a cultivated soil. The accumulation of ions in above-ground tissue was determined in the all three studied plants, considering the fact that maintaining a stable cytosolic Na+/K+ ratio has become a crucial salinity tolerance mechanism. The higher salinity of soil resulted in high level of Na+ ions in leaves, increased synthesis of osmolyte components and robust antioxidant activities to combat the oxidative stress. As whole, changes in cellular metabolites were determined by using FT-IR spectroscopy, evident as differential FT-IR profiles in both leaves and stem specific to these metabolites. The considerable amounts of HMs accumulation including Zn, Fe, Mn, Cu, Cr, and Cd with highest being Fe in above-ground tissue of all three studied halophytes were obtained. These preliminary findings represent S. monoica, T. indica and C. cretica as potent phytoremediation plant using phytosequestration to accumulate HMs. The present study project a light on the use of these three plants in reclamation of degraded saline soils.

Accumulation and transformation of benzo[a]pyrene in Haplic Chernozem under artificial contamination.

Abstract: Polycyclic aromatic hydrocarbons (PAHs) have been a major concern because of their carcinogenicity, mutagenicity, teratogenicity and wide distribution in the environment. Over 90% of PAHs in the environment exist on soil surface/sediment. Benzo[a]pyrene (BaP) is one of the predominant PAHs in soil. Thus, it is critically important to understand the patterns of BaP accumulation and transformation peculiarities in soil for the risk assessment. The studies were conducted in model experiment with Haplic Chernozem spiked with various doses of BaP (20, 200, 400 and 800 µg kg−1) equivalent to 1, 10, 20 and 40 levels of maximum permissible concentrations. The unique properties of Haplic Chernozem were studied allow to accumulate and transform BaP as well as barley plants ability to absorb of some BaP concentration. Extraction of BaP from the soil was carried out by the saponification method. The qualitative and quantitative determination of BaP and other polycyclic aromatic hydrocarbons (PAHs) was performed by high-performance liquid chromatography with fluorescence detection (Agilent 1260 Germany, 2014). BaP accumulation in soil depended on the applied BaP concentrations in Haplic Chernozem. Studying the features of PAHs transformation in the soil of a model experiment 1 year after the compound application showed the BaP content in the soil decreased up to 11–40%. Two years after the BaP application the content in the soil decreased up to 15–44% from the initial BaP content in the soil. The percentage of BaP concentration reduction in Haplic Chernozem increased with an increase in the dose of the applied xenobiotic. An increase in the dose of the applied pollutant to the soil of the model experiment contributed to an increase in all PAHs, which indicated a rapid BaP transformation in Haplic Chernozem. The PAHs content in the soils of model experiment in the first year of the research formed the following descending series: pyrene > chrysene > fluoranthene > phenanthrene. In the second year of research the phenanthrene content became higher than the fluoranthene content. The content of these compounds exceeded 20% of the total PAHs content in the soil samples in the first and second years of the model experiment. The features of PAHs accumulation and transformation in soils under artificial pollution showed the degradation of large-nuclear PAHs, starting from 5-ring polyarenes, and their structural reorganization into the less-nuclear polyarenes, such as 4-, 3-, and 2-ring PAHs. During the 2 years of the model experiment the BaP concentration in the soil decreased up to 15–44% from the initial BaP content in the soil.

Comparison of Heavy Metal Content in Artemisia austriaca in Various Impact Zones.

Abstract: A study on Artemisia austriaca of two anthropogenically heavy metal-polluted impact zones of the Rostov region, namely Lake Atamanskoye and Novocherkasskaya Power Station, was conducted. The influence of soil pollution on the Pb, Zn, and Cu accumulation in various organs of A. austriaca, which is widespread in the studied territories, was established. An extremely high level of Zn content (3051 mg/kg) was observed in the soils of the impact zone of Lake Atamanskoe, as well as an excess over the maximum permissible level for Pb and Cu (32 and 132 mg/kg accordingly). The distribution coefficient (DC) of heavy metal translocation showed the highest mobility of Zn (DC ≥ 1 in 9 out of 11 sites) and the smallest of Pb (DC ≥ 1 in 4 out of 11 sites) in plants of the Novocherkasskaya Power Station impact zone. The zone of increased pollution around Lake Atamanskoye was 1.5 km, which was much smaller than the Novocherkasskaya Power Station zone of high pollution (5 km). However, vehicle emissions accumulated in the soil over the past decades had a greater effect on the Pb translocation than atmospheric emissions of the enterprise.

Advances in Entomopathogen Isolation: A Case of Bacteria and Fungi

Abstract: Entomopathogenic bacteria and fungi are quite frequently found in soils and insect cadavers. The first step in utilizing these microbes as biopesticides is to isolate them, and several culture media and insect baiting procedures have been tested in this direction. In this work, the authors review the current techniques that have been developed so far, in the last five decades, and display brief protocols which can be adopted for the isolations of these entomopathogens. Among bacteria, this review focuses on Serratia spp. and bacteria from the class Bacilli. Among fungi, the review focuses those from the order Hypocreales, for example, genera Beauveria, Clonostachys, Lecanicillium, Metarhizium, and Purpureocillium. The authors chose these groups of entomopathogenic bacteria and fungi based on their importance in the microbial biopesticide market.

An Overview of Micronutrients: Prospects and Implication in Crop Production

Abstract: Micronutrients are important for plant growth and they significantly play an important role in balanced crop nutrition. They are vital for appropriate growth and development of plants in their entire life span. A deficiency of any one of the micronutrients in the soil can limit the growth of plants, even when all other nutrients are available in adequate amounts. The deficiency of micronutrients is widespread in many areas due to the nature of soils, high pH, low organic matter, salt stress, continuous drought, high bicarbonate content in irrigation water and imbalanced application of fertilisers. In India, the most deficient micronutrient in the soil is Zn, followed by B. In recent years, the deficiency of micronutrient has risen to a great extent. Zn and B deficiencies are focussed mainly for their adverse impacts on human health and food production. This chapter attempts to examine the defects of Zn, Fe, Mn, Cu, B and Mo deficiency in the soil and crops as well as the management of micronutrient deficiencies by way of fertilisation, development of agronomic strategies and creation of awareness of micronutrient dose. Deficiencies of Zn and B cause some severe complications in crop production in India. In view of the problems, we discuss the importance of micronutrients in agriculture and their roles and ways to improve crop productivity.

Assessment of extraction methods for studying the fractional composition of Cu and Zn in uncontaminated and contaminated soils

Abstract: This study is aimed at elucidating the fractionation of Cu and Zn in Haplic Chernozem and its alteration under the contamination to evaluate the extraction selectivity of different extractants and thus the efficiency of three sequential extraction schemes (Tessier and McLaren five-step and modified BCR three-step methods). General trends in the distribution of Cu and Zn speciations revealed with these three fractionation schemes suggest that they can be applied for the soils and the obtained results can be compared. Low mobility of potentially toxic metals (PTM) in the studied soil is suggested not only by their high content in residual fraction, but also by low contents of exchangeable and carbonate bound fractions (not more than 4-5 % Cu and 5-7 % Zn in the first two fractions). The highest contribution to the absorption and retention of Cu delivered from anthropogenic sources is made by organic matter and sesquioxides (up to 29 %); for Zn, by the nonsilicate Fe and Mn compounds (up to 25 %). However, the pattern of PTM extraction from soils varies during the application of different fractionation methods. The Tessier method is distinguished by a higher extractability relative to organic matter and sesquioxides. Therefore, this method is more informative for the contaminated soils. The McLaren method makes it possible to track the weakly bound species of compounds without the risk of involving other soil components. The BCR method is marked by simplicity of application and, therefore, recommended only for the noncalcic or low-calcic soils.

Content of heavy metals in Haplic Chernozem under conditions of agrogenesis

Abstract: The paper presents the results of a long-term study on the content and distribution of heavy metals in Haplic Chernozem of agrocenoses in southern zone of Rostov Region. The impact of various agricultural technologies traditional (using moldboard ploughing) and resource-saving (minimum and No-till) on accumulation and mobility of Pb, Zn, Cu in Haplic Chernozem in winter wheat cultivation is considered. The total content of Pb, Zn, Cu in the winter wheat areas corresponds to the background level and does not exceed permissible concentrations. Low mobility of elements (Pb 2.0-3.0%; Zn and Cu up to 1.0% as a percentage of their total forms) is a regional soil feature. In addition, the low availability of Zn and Cu in soils is due to their removal with the crops in the absence of micronutrient fertilizer replenishment. The significant role of soil organic matter in the accumulation of both total and mobile forms of heavy metals in soil has been confirmed. The intensity of the cultivation methods used has a significant effect on the total content of Zn, Cu and on the mobility of Pb, Zn, Cu in Haplic Chernozem.

Zinc Solubilization and Mobilization: A Promising Approach for Cereals Biofortification

Abstract: Plants are an important component of the ecosystem and vital for survival of human beings. As human beings need nutrition for their proper growth and development, plants also require different nutrients to complete their life cycle. Among the all essential nutrients, zinc is one of the important nutrients required not only by plants but also by human beings. Several researchers have reported the decline in zinc level of Indian soils. An approx. 47–49% of Indian soils are facing zinc deficiency, which is continuously rising up. The deficient soils are not able to supply the crop the required amount of nutrients, since soils with zinc deficiency are unable to provide an adequate amount of nutrients. The cereal crop like rice is prone to face zinc deficiency worldwide. Keeping in view such global crop issues, a greater attention is required to fulfil the zinc requirement of crop by different agronomic and plant breeding approaches. Zinc biofortification becomes one of the promising strategies to supply zinc in the crop at an optimum level. Zinc solubilization and mobilization are one of the suitable strategies to overcome zinc-deficiency issues. The chapter has emphasized on mechanism of biofortification and its challenges and limitations for adoption at ground level.

Accumulating capacity of herbaceous plants of the Asteraceae and Poaceae families under technogenic soil pollution with zinc and cadmium

Abstract: In this study, the environmental monitoring of the long-term technogenic pollution zone of Novocherkassk, a region containing numerous heavy metal contaminations, was carried out. In the plants growing in the 5 km zone around Novocherkasskaya power station, contamination with the studied elements was revealed. The dependence of the content of Zn and Cd in herbaceous plants of the families Asteraceae and Poaceae on the distance to the source of the anthropogenic load was established. The selectivity of accumulation of metals by studied species of herbaceous plants at different levels of technogenic pollution is revealed. Achillea nobilis has the least pollutants resistant from the soil. Poa pratensis has the highest resistance to Zn and Cd pollution in terms of the set of assessment indicators. The granulometric composition of the soil has a significant impact on the availability of metals to plants.

Lead compounds in bottom sediments of the Seversky Donets floodplain

Abstract: Investigations on heavy metals in water bodies are extremely important in a comprehensive assessment when the anthropogenic activities disturb the natural environment. The present paper studies the composition of Pb compounds in highly contaminated bottom sediments of a natural settling basin of a chemical plant at the Atamanskoye lake in the floodplain of the Seversky Donets River by sequential fractionation. The predominance of the residual Pb fraction, which is represented by layered silicates (hydromuscovite, montmorillonite, kaolinite) is shown. Organic matter and Fe-Mn (hydr)oxides also play an important role in metal interaction. High mobility of Pb is noted, which associated with imposing high environmental risks in the studied area.

A comparative evaluation of genetic material from quercus robur l. Stem tissues of different age and living states

Abstract: Qualitative and quantitative evaluation of the total DNA extracts from the steams tissues of different morphological locations was performed for ecologically and economically important wood tree species pedunculate oak (Quercus robur L.). Generally, the younger plant leaves are known to have a significantly higher content of the undegraded DNA. However, sometimes it is difficult to collect them practically. It follows that qualitative and quantitative DNA isolation may require other organs and tissues of plants, such as the stems. Three types of primers, i.e., nuclear DNA degenerate ISSR-primer UBC 841; chloroplast DNA-primers complementary to the gene fragment (rbcl_a) of a large subunit of 1,5-ribulose-bisphosphate carboxylase/oxygenase (RuBisCO) and mitochondrial DNA-primers targeting the gene encoding ATPase 1 (atp 1) were used for the qualitative evaluation of total DNA extraction. The highest concentration of total DNA was found in the phloem and cambium (35.23 ng/μl for the wood cuts from living plants and 12.62 ng/μl for the wood cuts of dead plants) obtained from the Q. robur L. stems. Successful enzymatic amplification of the isolated DNA was achieved only for the objects from the locations related to the cambium, bast, and sapwoods tissues of stems. Generally, it has been shown that Q. robur L. stem can be used for the obtaining of an acceptable concentrations of a good quality DNA. The results of the current study are presented for the first time to make the practical recommendations for sampling the tissues from a living woody tree with the subsequent PCR analysis.