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The information about the use of plant growth-promoting endophytic bacteria (PGPEB) with ornamental plants is still scarce. This study was designed to isolate and characterize PGPEB from different ...

Liquid microbial inoculants have recently received great attention due to their vital roles for sustainable agricultural practices. However, long-term conservation under ambient temperature conditions and deleterious environmental factors might negatively impact microbial cell survival and limit their efficacy in the field. Thus, developing efficient liquid formulation providing prolonged survival of rhizobia in the final product and after an application is crucial. Therefore, this study investigates the effect of various additives on the long-term survival of rhizobia stored in liquid cultures at room temperature (25 °C) for 12 months. Various yeast sucrose media amended with polyvinylpyrrolidone (PVP) or gum arabic as colloidal agents in combination with ectoine (as a compatible solute) and/or glycerol were evaluated. A dramatic decline in viable cell count was obtained in formulas amended only with PVP from Log 8.5 to Log 5 in the first six months and then to Log 1.5 after 12 months. In contrast, rhizobia stored at PVP-based formulas amended with 10 mg L‒1 ectoine exhibited almost constant survival level till the end of the storage period. The same trend was obtained using formulas based on gum arabic as a colloidal dispersing agent; however, less decline in cell count using a formula containing gum arabic alone as compared to using PVP. On the other hand, PVP based formulas exhibited higher viscosity compared with another formula. Increased viscosity till the 8th month of storage was achieved in the presence of ectoine indicating the increase of exopolymeric substances production. Electrophoretic protein pattern of rhizobial cells (stored for 12 months) exhibited several low molecular weight protein bands in cells stored in PVP based formula with ectoine as compared to the other treatments. Thus, the amendment of the liquid formulation of rhizobia bioinoculant with PVP plus ectoine not only improved cell survival but also enhanced the culture viscosity and consequently ameliorate the colonization and performance of rhizobial inoculants.

The plant growth-promoting rhizobacteria (PGPR) application could reduce the use of synthetic fertilizers and increase the sustainability of crop production. Halophilic bacteria that have PGPR characteristics can be used in different environmental stresses. Two different strains isolated, purified, characterized as a PGPRs and phylogenetic identification using 16sRNA which was revealed to be closest matched at 99% with Bacillus halotolerans and Lelliottia amnigena. The isolates possessed plant growth promoting properties as exopolysaccharides (EPS) and indole acetic acid (IAA) production, Bacillus halotolerans had the ability to fix elemental nitrogen and the two strains have the ability to P-solubilization. Furthermore, the strains were evaluated in alleviation of different levels of salt stress on wheat plant at two experiments (Pots and a Field). Strains under study conditions significantly increased the plant height, straw dry weight (DW g plant-1), spike number, 1000 grain DW recorded 31.550 g with Lelliottia amnigena MSR-M49 compared to un-inoculated and other strain in field, grain yield recorded 2.77 (ton fed-1) with Lelliottia amnigena as well as N% and protein content in grains recorded 1.213% and 6.916 respectively with inoculation with Lelliottia amnigena, also, spikes length, inoculated wheat show reduction in both proline accumulation in shoots and roots especially with Lelliottia amnigena recorded 2.79 (mg g-1DW), inoculation significantly increased K+ in root-shoot, K+/Na+ in root-shoot and reduced Na+ in root-shoot compared with control. This confirmed that this consortium could provide growers with a sustainable approach to reduce salt effect on wheat production.

Soil is an important source of resources required for human health and well-being. Soil is also a major environmental reservoir of pathogenic organisms. This may include viruses like the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which through 2020 and 2021 created dramatic catastrophes worldwide as the causative agent of the coronavirus disease of 2019 (COVID-19). So, soil has both positive and negative impacts on human health. One of the major positive impacts is the transfer of nutrients from soil to plants, and from there to humans through their diet. Biofortification is able to enhance the levels of nutrients essential to human health in the crops we consume and represents a sustainable solution to address malnutrition, which in turn may strengthen the human immune system against COVID-19. This nutrient transfer works better when we have healthy soils. Therefore, soils and biofortification have important roles to play in combatting the COVID-19 pandemic. However, several questions still remain, such as what are the expected environmental impacts of COVID-19 on soil? Can SARS-CoV-2 be transmitted through soil, and under what conditions? Which soil processes and properties influence SARS-CoV-2 survival rates and times, as well as transmission? What are the specific links between soil health and COVID-19? What are the projected soil management scenarios in response to COVID-19? Questions such as these deserve more attention as the world seeks to recover from its most recent pandemic.

The similarity between plant and microbial cells encourage the use of microbial metabolites of halophilic bacteria for the alleviation of salt stress in plants. In the current research work, a compatible solute ectoine extracted from a moderately halophilic bacteria Chromohalobacter salexigens KT989776 was used to enhance flax germination and primary seedling under different levels of salinity. Two successive experiments including germination in Petri plates under six levels of salinity (0, 3, 5, 7, 9 and 11 dS.m-1) and a pot experiment under three irrigating water salinity levels (2, 3 and 4) with two types of ectoine application (spray and soil addition) were conducted. Germination parameters were recorded for the first experiment while a fresh and dry weight of plants and peroxidase activity in addition to sodium-potassium ratio were estimated in the pot experiment. Also, ectoine accumulation in plants was detected using HPLC. Results of LC-MS proved the production of ectoine by C. salexigens KT989776 and ectoine enhanced significantly all germination parameters of flax seeds, decreased sodium accumulation in the plant, increased potassium content, and lowered peroxidase and phenoloxidase activity. Also, HPLC analysis proved that ectoine was detected in all treated samples while not detected in non-treated control.

Stressed environments have long been a question of great interest in a wide range of fields. So, many considerable literatures have grown up around this theme. In Egypt, there are several common problems related to the stressed environments. These stresses include decline of soil fertility, soil salinity and alkalinity, soil water logging, salt-affected soils, soil pollution, climate change, over-population growth, urban sprawl, land degradation, deterioration of natural resources, etc. More generally, national income will decline and will in turn result in the spread of social and political problems. Kafr El-Sheikh governorate can be considered one of the most important areas in Egypt, which calls "the governorate of the hope and the future" due to its location and wealths. Whereas, this governorate suffers from the most common stresses in Egypt including pollution, salinity, alkalinity and waterlogging. Great problems have been recorded in Kafr El-Sheikh related to stressed environments and suggested solutions also have been addressed. Therefore, a sustainable management should be adapted for overcoming these stressed environments in Kafr El-Sheikh.

THE GLOBAL agricultural production suffers from many problems and challenges including climate change, natural resources depletion, environmental pollution, soil degradation, etc. Hence, the global security of this vital sector definitely will be threaten including water security, soil security, energy security, food security, etc. Day by day, several attempts already have been conducted in seeking of the humanity for suitable and sustainable solutions to overcome these previous problems. Nanotechnology was and still one of the most important solutions, which will help us to overcome these problems. So, several nanomaterials have been successfully used in many agro-production fields including nanofertilizers, nanopesticides, nanoremediation, nanobiosensors as well as using of nanoparticles in agri-food production. These nanomaterials can help the agro-production to exploit the natural resources in more sustainable manner and to minimize the agro-wastes. Therefore, regulations for more safety in nanomaterials utilization for agro-production should be starting from the handling for seed germination till the handling for postharvest of agricultural products. Several investigations have been proved the importance of nanomaterials in global securities, the agro-production through the nano-agro-chemicals, management of the agro-wastes, etc. Therefore, this review will highlight new insights and novel approaches for using nanomaterials for sustainable agro-productivity. It will also include the impact of nanomaterials on the agro-environement and the enhanced productivity in frame of sustainability.

Human health and its improvement are the main target of several studies related to medical, agricultural and industrial sciences. The human health is the primary conclusion of many studies. The improving of human health may include supplying the people with enough and safe nutrients against malnutrition to fight against multiple diseases like COVID-19. Biofortification is a process by which the edible plants can be enriched with essential nutrients for human health against malnutrition. After the great success of biofortification approach in the human struggle against malnutrition, a new biotechnological tool in enriching the crops with essential nutrients in the form of nanoparticles to supplement human diet with balanced diet is called nano-biofortification. Nano biofortification can be achieved by applying the nano particles of essential nutrients (e.g., Cu, Fe, Se and Zn) foliar or their nano-fertilizers in soils or waters. Not all essential nutrients for human nutrition can be biofortified in the nano-form using all edible plants but there are several obstacles prevent this approach. These stumbling blocks are increased due to COVID-19 and its problems including the global trade, global breakdown between countries, and global crisis of food production. The main target of this review was to evaluate the nano-biofortification process and its using against malnutrition as a new approach in the era of COVID-19. This review also opens many questions, which are needed to be answered like is nano-biofortification a promising solution against malnutrition? Is COVID-19 will increase the global crisis of malnutrition? What is the best method of applied nano-nutrients to achieve nano-biofortification? What are the challenges of nano-biofortification during and post of the COVID-19?

The global food production and its quality face a lot of challenges, which already decreased the availability of these foods. These challenges were mainly linked to global climate changes and their ramifications, which are expressed as environmental stresses like drought, flooding, low or high heat stress. The new pandemics like COVID-19 also represent a new challenge for the entire universe. Although, there are increasing concerns about combined stress on cultivated plants, still more studies are needed to cover all botanical issues including physiological, morphological, biochemical and histological traits. Further studies are required to focus on different combined or multiple stresses in particular the individual stress is rare in the nature. This work is an invitation for publication reviews, comments, notes and original articles about the anatomical changes in stressful plants particularly under combined stress. The EBSS journal also welcomes the serious and promising studies, which will handle the environmental issues related to stress in the era of COVID-19.

Graphical abstract The health sector is critical to the well-being of any country, but developing countries have several obstacles that prevent them from providing adequate health care. This became an even larger concern after the COVID-19 outbreak left millions of people dead worldwide and generated huge amounts of infected or potentially infected wastes. The management and disposal of medical wastes during and post-COVID-19 represent a major challenge in all countries, but this challenge is particularly great for developing countries that do not have robust waste disposal infrastructure. The main problems in developing countries include inefficient treatment procedures, limited capacity of healthcare facilities, and improper waste disposal procedures. The management of medical wastes in most developing countries was primitive prior to the pandemic. The improper treatment and disposal of these wastes in our current situation may further speed COVID-19 spread, creating a serious risk for workers in the medical and sanitation fields, patients, and all of society. Therefore, there is a critical need to discuss emerging challenges in handling, treating, and disposing of medical wastes in developing countries during and after the COVID-19 outbreak. There is a need to determine best disposal techniques given the conditions and limitations under which developing countries operate. Several open questions need to be investigated concerning this global issue, such as to what extent developing countries can control the expected environmental impacts of COVID-19, particularly those related to medical wastes? What are the projected management scenarios for medical wastes under the COVID-19 outbreak? And what are the major environmental risks posed by contaminated wastes related to COVID-19 treatment? Studies directed at the questions above, careful planning, the use of large capacity mobile recycling facilities, and following established guidelines for disposal of medical wastes should reduce risk of COVID-19 spread in developing countries.

Undoubtedly, COVID-19 pandemic is one of the most devastating pandemics in the recent era and major problem for sustainability of life. This virus has severely impacted both environmental and human health. Moreover, it has become the top priority among other challenging global issues including pollution, climate change, urbanization, and unsustainable consumption, which have led to major environmental disturbances and biodiversity loss. The COVID-19 may have long-lasting impacts on the environment health, biodiversity, and soil security, consequently, will raising several scientific questions to be investigated in near future including the expected environmental impacts of COVID-19 on soil, water and air, connecting the missing links between environmental pollutions and COVID-19. Most importantly, unraveling the role of soil in spreading or reducing transmission of the COVID-19 pandemic, and soil xenobiotics status under the COVID-19 outbreak. Understanding the projected management scenario of soil and freshwater pollution in the post-COVID-19 era and the potential impact of COVID-19 on food and soil security would be of immense aid in the preparation of future pandemics. This opinion article aims to analyze and foresee some of the major issues for meeting the United Nation’s Sustainable Development Goals.

By the end of 2019, the universe was woken up to see one of the unprecedented dramatic catastrophes all the over the world, which called the COVID-19 pandemic or coronavirus. This virus already changed the global map and enforced the globe to start a new era that no one can predict the volume of changes worldwide on social, economic and environmental levels. The pollution of soil and air as two compartments of the agroecosystem were and still represent two vital columns of the environment structure. Based on the social distancing, lockdown and quarantine, the air pollution was reduced in several cities worldwide, whereas this relationship on soil as a complex system still needs mor and more investigations. Therefore, the most immediate impacts of the COVID-19 pandemic on soils and vice versa are mainly depending on the human activities. The managing soils may include both restoring of soils from the virus impacts and to sustain crop yields for long-term sustainability to keep the soil healthy for next generations. Therefore, this review is an attempt to highlight the mutual impact of COVID-19 on pollution of soil and air. Many open questions are needed to be investigated such as what are the expected environmental impacts of COVID-19 on soil and air? Is there any links between air pollution and COVID-19? Is there any role of soil in spreading the COVID-19 pandemic? What about the soil pollution status under COVID-19 outbreak? What is the projected management scenario of soil and air pollution under COVID-19 outbreak? What is the potential presence of COVID-19 and its behavior in the soil?

The human activities may include the agricultural, industrial and other activities. The agricultural sector is considered the main source for our life’s supplies. Thus,the agriculturalactivities or practices might result many pollutants such as applied mineral fertilizers, pesticides, effluents from domestic and industrial sewages and vehicular emissions.Therefore, a remediation to remove or decrease the pollutants in soil and water is needed for the environmental protection. This remediation has several classic strategies several years ago, but a promising and new approaches have been established particularly nano-remediation. This nano-remediation depends on the applied nanomaterials in removing pollutants from soils and water through nano-bioremediation and nano-phytoremediation. The most important nanomaterials that have the potential in removing pollutants from contaminated soils and water nano-silica, nano-zero-valent of iron, nano-sized ironsulfide particles, nano-ZnO and others. However, many challenges or open questions are still needing a justification because using of nanomaterials in higher concentrations are considered toxic to plants and agro-environment. Are these nanomaterials stable under environmental conditions or will be converted into toxic ones or still need to be identified for sustainablenano-remediation? Is there any possibility to enter the nanomaterials or other toxic compounds the food chain through these plants? Therefore, a lot of further questions and further research are needed concerning the nano-remediation in removal the agro-pollutants.

The world’s burgeoning population faces a great challenge concerning food security, which could be achieved through different sustainable agricultural practices. Trichoderma, as a ubiquitous fungus, is one of the most promising microorganisms that might offer several avenues for sustainable agriculture. Trichoderma spp. may guarantee a better solution for conventional problems in agriculture through several approaches including the protection of cultivated plants from undesirable abiotic and biotic conditions under changing environments and promoting their growth in poor or limited soil nutrients. The promising role of Trichoderma for vegetable production as a biocontrol and biofertilizers has been confirmed but this role of Trichoderma as a plant pathogen still needs more studies. Trichoderma could inhibit or suppress the growth of soil phytopathogens, promoting plant growth and soil health, through activation of many mechanisms including synthesis of antibiotics, mycoparasitism and competition for nutrients against plant deleterious microorganisms. The sustainable approaches of Trichoderma including biofortification, bio-remediation and phyto-remediation as well as exploring future research opportunities will be also handled in this work.

Agricultural wastes are considered residues resulted from the agricultural production and after harvesting fruit and vegetable and their processing, agro-industrial by/co-products from the grapes, banana, olives and milk processing. These wastes may represent a treasure when they are turning into valuable applications (i.e., composting, biochar, removing pollutants from the environment and organic fertilizers) or they may burn in open fields causing some environmental problems such as soil degradation and air pollution. The landfill disposal and open dumping of agro-wastes is a common practice in the developing countries generating huge amounts of ash, which may create serious health and environmental problems, primarily due to pollution of groundwater. Under the umbrella of the bioeconomy and based on industrial innovation and high technology, new and better approaches for the recovery of agricultural wastes have been developed. This has contributed to guaranteeing sustainable production and its consumption, resource efficiency, the conversation of these wastes into valuable products and the reduction of negative environmental impacts. The common management of Agro-wastes may include a lot of suggested uses such as production of biosynthesis of nanoparticles, biotechnological products, composting and biofuel production. A lot of bioactive compounds could be produced from the agro-wastes, which have many application possibilities such as functional food, pharmaceutical and cosmetic approaches. The nano-management of agro-wastes may include using of nanotechnology to convert the agro-wastes into a valuable product. This topic still has several open questions particularly under the sustainable and bioeconomy.

In this study, the production of lactic acid (LA) from beet molasses, a by-product of the beet sugar industry was investigated using newly isolated potential lactic acid bacteria. Isolate ds10 was selected amongst 138 bacterial isolates obtained from natural sources. This isolate was identified as Enterococcus hirae ds10 based on morphological, biochemical and molecular characteristics using 16S rRNA sequence. Direct utilization of molasses achieved low LA production at 2.01 g L‒1. Different molasses’ pretreatment methods were investigated. Molasses treated with EDTA were considered as the best substrate achieving effective LA production at 11.39 ± 2.07 g L‒1. Furthermore, medium constituent was optimized, where supplementation of 0.5% (w/v) ammonium chloride and 0.05% (w/v) yeast extract exhibited the best fermentation medium. Further optimization of fermentation factors was performed by using one-factor-at-a-time (OFAT) and response surface Minitab 18 software approaches. OFAT technique achieved the maximum LA production of 25.4 ± 0.42 g L‒1 after 24 h at sugar molasses conc., 4% (w/v); inoculum size, 10% (v/v); pH, 8.0; and temperature, 40 °C. Whereas, response surface Minitab 18 software approach resulted in a 60% increase in LA production achieving 40.69 g L‒1 at 60 g L‒1 sugar concentration, 0.625 g L‒1 yeast extract, 40 °C, pH 8 and 9.5% inoculum size. The optimization strategy in this study could achieve a 20-fold increase in LA production as compared to initial production.

Metal oxides play an essential role in the photocatalysis of contaminants and substantially increase in the environment by the engineering production. However, whether emerging contaminants will be produced during photocatalysis of contaminants remains unclear. Here, triclosan (TCS) photodegradation in metal oxides/silica suspensions and particles, simulated as the states of metal oxides in water and soil environments, were studied. The photodegradation results confirmed that metal oxides exhibited a double-effect. They promoted TCS photodegradation by generating reactive oxidizing species (ROS) in metal oxides/silica suspensions and inhibited the photodegradation by competing with TCS for irradiation in metal oxides/silica particles. In this study, the critical discovery was the formation of emerging contaminants, environmentally persistent free radicals (EPFRs), and EPFRs yields were promoted by metal oxides (Al

Many global problems threaten our life on the Planet including climate changes, environmental pollution, food and soil security, energy crisis, etc. This environmental pollution has not only mainly serious risks and stress involving the human health and the entire ecosystem safety but also the quantity and quality of crop productivity worldwide. Due to the great gap between the global food production and the global consumption, there is a crucial need to cultivate these contaminated lands sooner or later. Therefore, the removing of pollutants from soils and waters should be performed in frame of sustainable remediation and sustainable energy production. Depending on many factors (source and kind of pollutants, land use and the economics of water and soil resources, etc) many strategies should be addressed for the sustainable and integrated management of polluted lands. Nanoremediation is a promising strategy in controlling pollution and management. Three major applications of nanoremediation could be characterized including detection of pollution using nanosensors, prevention of pollution, purification and remediation of contamination. Further studies also concerning the impact of changing climate on the nanoremediation process in the agroecosystems should be considered. Thus, this review will focus on the evaluation of environmental nanoremediation and its strategy in polluted lands under climate changes. Using of nanotechnology in pollution control as well as the environmental pollution and its sustainable management also will be highlighted.

NANOTECHNOLOGY has been revolutionized penetrating all sectors in our life through the nanoscience as an essential science for a wide range of technologies. Amazing achievements resulted from this nanotechnology including all agricultural fields such as plant nutrition and crop productivity, energy sector, food sector, and plant biotechnology. A conjugation between plant biotechnology and nanotechnology has been produced an important science called plant bio-nanotechnology. Several fields have been invaded through different nanobiotechnology applications in agriculture including (1) the nanotechnology of encapsulated agro-chemicals, (2) the monitoring of different environmental stresses and crop conditions using nanobiosensors, (3) the improvement of crop production and ameliorating plants against diseases and (4) solution several environmental problems. The crop productivity also could be improved using some new agro-chemicals (e.g., nanofertilizers and nanopesticides). These agro-chemicals are very effective in delivering encapsulating nanomaterials and then enhancement the productivity of crops as well as the suppress plant pests and diseases and protecting the environment from pollution. On the other hand, nanoparticles could enter the food chain via different nano-agrochemicals or nano-processed foods. Therefore, many approaches including uptake of nanoparticles by plants, entry and bio-distribution of nanoparticles into the food chain are needed before using of different bionanotechnological tools in agro-production sector. Further new regulations should be created or re-built for new approaches in plant bionanotechnology. Therefore, this review will focus on our needs and risks in the plant nano-biotechnology.

Lignocellulosic and algal biomass are promising substrates for lactic acid (LA) production. However, lack of xylose utilization and/or sequential utilization of mixed-sugars (carbon catabolite repression, CCR) from biomass hydrolysates by most microorganisms limits achievable titers, yields, and productivities for economical industry-scale production. This study aimed to design lignocellulose-derived substrates for efficient LA production by a thermophilic, xylose-utilizing, and inhibitor-resistant Bacillus coagulans Azu-10. This strain produced 102.2 g/L of LA from 104 g/L xylose at a yield of 1.0 g/g and productivity of 3.18 g/L/h. The CCR effect and LA production were investigated using different mixtures of glucose (G), cellobiose (C), and/or xylose (X). Strain Azu-10 has efficiently co-utilized GX and CX mixture without CCR; however, total substrate concentration (>75 g/L) was the only limiting factor. The strain completely consumed GX and CX mixture and homoferemnatively produced LA up to 76.9 g/L. On the other hand, fermentation with GC mixture exhibited obvious CCR where both glucose concentration (>25 g/L) and total sugar concentration (>50 g/L) were the limiting factors. A maximum LA production of 50.3 g/L was produced from GC mixture with a yield of 0.93 g/g and productivity of 2.09 g/L/h. Batch fermentation of GCX mixture achieved a maximum LA concentration of 62.7 g/L at LA yield of 0.962 g/g and productivity of 1.3 g/L/h. Fermentation of GX and CX mixture was the best biomass for LA production. Fed-batch fermentation with GX mixture achieved LA production of 83.6 g/L at a yield of 0.895 g/g and productivity of 1.39 g/L/h.

Different fermentation strategies were investigated for improving lactic acid (LA) production by homofermentative LA-producing strain, Enterococcus hirae ds10. Batch mode with initial sugar molasses of 69.53 g/L achieved LA production of 36.79 g/L with a yield of 0.91 g/g and productivity of 1.02 g/L/h; however, 52% of sugar molasses was only consumed. Otherwise, in batch mode with high cell density (HCD), strain ds10 consumed more substrate achieving LA production at 49.49 g/L at yield (0.91 g/g) and low LA productivity (0.41 g/L/h). Subsequently, one-pulse and multi-pulse fed-batch strategies with/without HCD were provided better sugar utilization and higher LA production but low LA productivity was obtained. Interestingly, the repeated batch fermentation was conducted for 16 runs and achieved the highest LA of 61.76 g/L after 30 h at a higher initial sugar concentration of 85.87 g/L with an improvement of LA productivity at 2.06 g/L/h and yield at 0. 97 g/g.

Broomrape parasitism on faba bean (Vicia faba L.) is the most destructive factor for this crop in Egypt. Pot experiments were conducted during the two successive seasons 2017/2018 and 2018/2019 to study the mitigation of broomrape stress on faba bean using a ten-fold dilution of 10% (w/v) spent mushroom substrate extract (SMSE) of Pleurotus ostreatus and the same dilution of culture filtrate of mushroom (MCF) grown in potato dextrose broth (PDB) at a rate of 48 l hectare&minus, 1 compared with the commercial herbicide Roundup (Glyphosate 48% emulsifiable concentrate) at a rate of 144 cm3 ha&minus, 1 on the two varieties (Misr3 and Sakha3) cultivated in broomrape-infested soil. The treatments include the use of mushroom products as foliar spray and/or soil amendment in addition to Roundup spraying as a recommended treatment. Using Gas Chromatography-Mass Spectrometry (GC-MS) spectroscopy, our results indicate that the major components of the two mushroom products were bioactive compounds such as polyphenol and high molecular weight aliphatic and aromatic hydrocarbons that may interfere with parasite and host metabolism. These results indicated that SMSE of P. ostreatus and MCF of the same mushroom grown in potato dextrose broth (PDB) gave the best control of broomrape, and increased plant height, root length, leaf area, chlorophyll concentration, relative water content and seed yield (g plant&minus, 1), as well as anatomical characters of leaves in the two faba bean varieties (Misr3 and Sakha3), such as upper and lower epidermis, palisade tissue, spongy tissue and vascular bundles. Additionally, electrolyte leakage was decreased in the treated plants compared to control plants and the plants treated with Roundup (glyphosate) because of the important role of SMSE and MCF in the improvement of faba bean water status.

Selenium is an essential micronutrient required for the health of humans and lower plants, but its importance for higher plants is still being investigated. The biological functions of Se related to human health revolve around its presence in 25 known selenoproteins (e.g., selenocysteine or the 21st amino acid). Humans may receive their required Se through plant uptake of soil Se, foods enriched in Se, or Se dietary supplements. Selenium nanoparticles (Se-NPs) have been applied to biofortified foods and feeds. Due to low toxicity and high efficiency, Se-NPs are used in applications such as cancer therapy and nano-medicines. Selenium and nano-selenium may be able to support and enhance the productivity of cultivated plants and animals under stressful conditions because they are antimicrobial and anti-carcinogenic agents, with antioxidant capacity and immune-modulatory efficacy. Thus, nano-selenium could be inserted in the feeds of fish and livestock to improvise stress resilience and productivity. This review offers new insights in Se and Se-NPs biofortification for edible plants and farm animals under stressful environments. Further, extensive research on Se-NPs is required to identify possible adverse effects on humans and their cytotoxicity.

Soil has a great and holy position worldwide. This position has been acquired from the importance of soil in saving food, feed, fuel, and fibre for animals and humans. Egypt was and still one of the most important countries, which soils played a crucial role in the Egyptian civilization. Therefore, very strong link between soils and humans has been reported based on the great roles of soils in plant and human nutrition. On the other hand, there are several anthropogenic activities, which cause many problems for soils such as pollution, degradation, and erosion. There are direct and/or indirect effects of soils on human health as well as plants. Therefore, this chapter is an attempt to emphasize the great roles of soils in plant and human health as well as the security of soils under pollution conditions.

It is well established that the nutrients of plant play a vital role in all plant processes starting from the emergence, development, productivity, and metabolism reaching to the promotion and protection of plants. These plant nutrients could be in general characterized as macronutrients (e.g., Ca, Mg S, N, K, and P) and micronutrients (i.e., Fe, B, Cu, Mn, Cl, Ni, Mo, Co, and Zn) as well as beneficial elements (e.g., Si, Se, Na, and V). These previous mineral nutrients also could protect crop plants against both abiotic and biotic stresses by enhancing the plant resistance power and regulating the mineral nutritional status. Therefore, any plant nutritional problems (like poor soil fertility, imbalance, and deprived delivery of nutrients) definitely will lead to reduce the global production of foods. Thus, it should protect crop production from different stresses through the appropriate agricultural management. Soil salinity was and still one of these plant stresses. A distinguished role of plant nutrients (e.g., N, K, Se, and Si) in ameliorating soil salinity stress has been reported as well as nano-selenium and nano-silica. Several reports have confirmed the great role of these previous plant nutrients under saline soil conditions. Therefore, this review will focus on the role of selenium and silicon in conventional and nano-forms under saline soil conditions. The phytoremediation of these saline soils and the role of plant nutrients will be also highlighted.

The application of both selenium (Se) and silicon (Si) could ameliorate different negative effects of abiotic and/or biotic stresses on plant growth. Under salt-stress conditions, selenium and silicon also could improve plant growth as well as increase the activity of enzymatic antioxidants, improving the balance of ions and osmotic adjustment. They could also use as a resistance provider against plant diseases and the attacks of insects as well as a nutrient supplement. They could also maintain the fertility of soils through improving the bioavailability of nutrients in soils for plants. Apart from selenium and silicon, nano-selenium and nano-silicon have gained a great attention nowadays as eco-friendly technologies. These technologies are considered very important for expanding the biological applications of the nanomaterials. These Se- and Si-nanomaterials have been developed in the field of nanotechnology in order to biosynthesize different nanomaterials for more applications. Many organisms recently have been used in biosynthesizing different varieties of inorganic nanomaterials in well-defined chemical composition. Nano-selenium and nano-silicon are considered promising nanoparticles in agriculture due to their significant roles in the biological systems. Many benefits could be gained from using these nanomaterials such as protection of plants against diseases and different stresses. These nanoparticles should be investigated in more details concerning the nano-safety research. Therefore, this chapter focuses on the beneficial roles of selenium and silicon elements for higher plants in the terrestrial environments, especially plant growth, uptake, and metabolism as well as biogenic synthesis of their elements by some organisms.

The field of nanotechnology has gained a great progress regarding the agriculture and food industry. Thereby, an excessive use of engineered nanomaterials has led to spread huge amounts of nanoscale materials in the agroecosystems. Soil–plant system was and still one of the most environmental compartments regarding the fate and behavior of nanoparticles. This system, which has more than a treasure, also represents the rhizosphere area including dynamic and fate of different nutrients as well as the microbial activity in soils. These treasures include the significance of soil–plant system in plant nutrition, the biogeochemistry of nutrients, pedosphere and its interactions with nutrients, phyto- or bioremediation and biofortification, soil fertilization, and the sustainability of agroecosystem. No doubt that nanoparticles may exhibit both negative and beneficial effects on higher plants including the physiological, molecular, and biochemical parameters of various plant parts. So, there is a crucial need for understanding different biochemical and physical processes of plants associated with the exposure for nanoparticles and evaluating the role of these nanoparticles in either enhancing or retarding these plant features. Therefore, the tasks of nanoparticles in mitigating or ameliorating the plant stress and phytotoxicity should be investigated in more detail. Furthermore, more comprehensive studies are needed in order to perform the expanded knowledge on the alterations induced by different nanoparticles on different plant mechanisms including the biochemical, physiological, and molecular levels. Moreover, long-term investigations are also needed to be conducted to evaluate different roles of nanoparticles in regulating various plant physiological processes under stress. One great mission is also requested regarding the construction of a global database, which would be helpful for setting a global nano-agro-database accessible and useful worldwide.

The plant root–soil interfaces could be considered the rhizosphere area, which is the most important active zone in the soils for different microbial activities, biodegradation of pollutants and plant nutrition. Polluted soils are characterized by low organic matter content, limiting their microbial activity, nutrient availability and degradation of pollutants. Soil phyto- and/or bioremediation is mainly based on the use of plant roots and their associated soil microorganisms, whereas conventional approaches are based on physico-chemical methods in soil remediation. Plant root exudates are the most important compounds in the rhizosphere, which play a crucial role in the interactions between plant roots and soil microbes. It is worthy to mention that several plant species and soil microbes have been used in soil remediation for different pollutants. The role of rhizosphere and its significance in plant nutrition are mainly controlled by the change in climatic attributes including temperature, moisture content, precipitation, etc. Therefore, global warming and climate changes do have a great and serious effect on the agricultural production through their effects on the rhizosphere and in turn plant nutrition. Hence, the aim of this review is to evaluate the significance of rhizosphere in plant nutrition under the changing climate. Soil biological activity and its security will be also highlighted.