eChapters

Molecular biology labo-ratories are becoming very common in every University and research institutes and a good laboratory manners is extremely important as many of the equipments are very expensive and sensitive. Hence familiarity with equipments becomes very crucial before starting any experiment.

Summary

Lac is a resinous exudation from the body of female scale insect Laccifer lacca Kerr. belongs to family Lacciferidae of phylum Arthropoda, class  Insecta and order Hemiptera. The lac insect lives on native trees in India, China,Thiland, Burma/Myanmar and Malaysia. In India it is chiefly grown on trees like Kusum, “Palas”, and “Ber. It is also purposely cultured on shoots of these tree species. Lac cultivation is an alternative agricultural profession and provides subsidiary source of income for a large number of farmers mainly in Jharkhand, Chhattisgarh, West Bengal, Odisha, North-East states and other parts of the country. India, which is the highest producer of lac, contributes around 55% of the total world requirement followed by China and Thiland. The country exports around 80-90% of its production.

Summary

Nanotechnology is an interdisciplinary areas of science and technology which refers broadly to a field of applied science and technology whose unifying theme of control of matter is on the molecular scale that integrates material science and biology. Due to their advantages over non-biological systems, several research groups have explored the use of biological systems for the synthesis of nanoparticles. Among the different microbes used for the synthesis of nanoparticles, fungi are efficient candidates for fabrication of metal nanoparticles both intra-and extracellulary. The nanoparticles synthesized using fungi present good polydispersity, dimensions and stability. The potential applications of nanotechnology and nanoparticles in different fields have revolutionized the health care, textile and agricultural industries and  they are described in present chapter.

Summary

Molecular evolution is the process of evolution at the scale of DNA, RNA, and Protein. Molecular evolution emerged as a scientific field in the 1960s as researchers from molecular biology, evolutionary biology, and population genetics sought to understand recent discoveries on the structure and function of nucleic acids and protein. It covers two broad areas of study : the evolution of macromolecules, and reconstruction of the evolutionary history of genes and organisms. The evolution of macromolecules refer to the characterization of the changes in the genetic material (DNA or RNA sequences) and its products (Proteins of RNA molecules) during evolutionary process, and to the rates and patterns with which such changes occur, and also the mechanism responsible for such changes. The second area also known as “molecular phylogenetics”, deals with the evolutionary history of organisms and macromolecules as inferred from molecular data and the methodology of tree reconstruction.

Summary

One of the most seductive lures of the genomic revolution is the promise of personalized medicine. The rapid identification of tens of thousands of human genes and hundreds of thousands of DNA variations that might influence disease susceptibility has spawned a new field Pharmacogenetics and Pharmacogenomics deal with the genetic basis underlying variable drug response in individual patients. The traditional pharmacogenetic approach relies on studying sequence variations in candidate genes suspected of affecting drug response i.e. single or few genes. On the other hand, pharmacogenomic studies encompass the sum of all genes, i.e., the genome. Numerous genes may play a role in drug response and toxicity, introducing a daunting level of complexity into the search for candidate genes. The high speed and specificity associated with newly emerging genomic technologies enable the search for relevant genes and their variants to include the entire genome.

Summary

Substance that acts as a catalyst in living organisms, regulating the rate at which life’s chemical reactions proceed without being altered in the process. Enzymes reduce the activation energy needed to start these reactions, without them, most such reactions would not take place at a useful rate. Because enzymes are not consumed, only tiny amounts of them are needed. Enzymes catalyze all aspects of cell metabolism, including the digestion of food, in which large nutrient molecules (including proteins, carbohydrates, and fats) are broken down into smaller molecules; the conservation and transformation of chemical energy and the construction of cellular materials and components. Almost all enzymes are proteins; many depend on a nonprotein cofactor, either a loosely associated organic compound (e.g., a vitamin) or a tightly bound metal ion (e.g., iron, zinc) or organic (often metal-containing) group.

Summary

The process of administration of a drug into the human body to cure a disease is regarded as drug delivery. The common routes of administration of the drugs include oral, nasal, inhalational, transdermal, dermal, ocular, rectal and vaginal. In the current chapter, an attempt has been made to discuss about the various methodologies which are being used to deliver the drug to the human patients.

Summary

Human being is dependent on nature and natural resources to combat diseases from time immemorial. Ayurveda describes the use of traditional herbs in medicinal preparations in ancient India. Such types of evidences are there in classical Chinese and Greek records also. Nowadays, modern tools are used to identify and purify the active principle from the herbal composition having the therapeutic effect. Bioinformatics tools are often used to screen the drug efficacy of natural products. Using computational and Bioinformatics tools, the efficacy of lead molecules can be screened. Moreover, drug targets can be identified using Bioinformatics and proteomics approach. QSAR and molecular docking tools are used to study the probable activity and mode of action of drug molecule. This approach has minimized the cost and time involved in the drug discovery process.

Summary

The present era is witness of understanding the science of human diseases at molecular level. The advances of science in terms of Genomics, Proteomics, Metaboliomics, Lipidomics and bioinformatics have drawn an excellent pathway to discover more promising drugs. It’s still a challenging task to reduce the time line to discover new drug, which is approximately 10-15 years. A drug discovery program requires billions of dollars but without the promise of success. After screening of thousands of compounds only one becomes successful in clinical trials and reaches to the market. Although there are lot many ways to approach drug discovery, nature has gifted many interesting compounds to fight the diseases. On the other hand isolation of pure compounds from natural products like bacteria found in soil or different parts of plants is itself a challenging area. The modern fashion of natural product isolation is guided by bioactivity. Hence a feasible assay to access the bioactivity has got a great importance.

Summary

Plants produce over 200,000 metabolites, which are important source of drugs and industrial materials. They have been traditionally classified as primary and secondary metabolites. The primary metabolites like sugars, amino acids and fatty acids that are needed for general growth and physiological development of plants are widely distributed in nature and are also utilized as food by man. Secondary metabolites are natural products, the absence of which does not result in immediate death, but in long term their impairment may lead to malfunction and reduced survivability. These plant secondary metabolites can be divided into groups that share the same core substructure, originated from the same biosynthetic pathways. Secondary metabolites play a major role in the adaptation of plants to the changing environment and in overcoming stress constraints. In this chapter we discussed the structure, properties, classification and functions of some of the important groups of plant secondary metabolites such as phenols, flavonoids, terpenoids and alkaloids. A brief overview of some of the important fungal secondary metabolites, their structures and importance has also been discussed. Biotechnological approaches which can be adopted to engineer plants for production of secondary metabolites have also been discussed.

Summary

RNA interference has revolutionized the concepts in regulation of gene expression. RNA interference is the mechanism that controls sequence specific gene silencing by double stranded RNA. These non-coding RNAs are gene specific regulators critical in the transformation of normal cells to a malignant stage. Alterations in the non-coding RNAs have been linked to specific cancers and can serve as diagnostic markers. The ability of exogenously introduced siRNAs to specifically bind its complementary mRNA and down regulate its expression has various applications. It has markedly influenced the way the role of certain genes is investigated in tumorigenesis. The siRNA technology has been effectively functional in identification of new components and blocking the expression of critical mediators in tumorigenesis.

Summary

Researchers face a series of similar-yet unique problems to isolate proteins. To solve these they must have dip knowledge to select an appropriate technique. The mechanism, to study the way in which a living system works, is necessary to dismantle the machine and to isolate the component parts so that they may be studied, separately and in their interaction with other parts. The knowledge that is gained in this way may be put to practical use, for example, in the design of medicines, diagnostics, pesticides, or industrial processes. In every case a pure protein is desirable as impurities may either be misleading, dangerous or unproductive, respectively. Protein isolation is, therefore, a very common, almost central, procedure in biotechnology. The purpose of this chapter is thus to fill the beginners with techniques relevant to protein isolation, hopefully to improve their knowledge.

Summary

Nanotechnology, the science of nanoscale structures has been applied in various fields including in biomedical sciences. Nanotechnology is being increasingly used to create materials and devices so as to interact with the body at sub-cellular scales with a high degree of specificity. Nanotechnology is used in the fight against cancer, cardiac and neurodegenerative disorders, infection and other diseases. This chapter provides an overview of some of the applications of nanotechnology in the field of biomedical sciences particularly with a focus on tissue engineering and medical diagnostics.

Summary

The indiscriminate use of pesticides and their persistence in the environment enhances the residue levels in meat, dairy products, eggs and food crops, consequently adversely affecting the human health (Akhtar, 1985). In India millions of tons of pesticides are applied to the agricultural fields to increase the productivity for compensation of the nutritional requirements of increasing population from the same land resources. It was the advent of green revolution that really spurred the growth of pesticide industry. Several reports published reveal that a large amount of organochlorine pesticides is present in vegetables, fruits and soft drinks besides other pesticides compared to World Health Organization (WHO) standards (Martin and Duggan, 1968; Corneliussen, 1969; Ulmann, 1972; Hildebrandt et al., 1986). Organochlorine pesticide persistence, biomagnification and toxicity adversely affect the ecological systems (Khanna et al., 2002). There are a large number of different types of pesticides which differ in their mechanisms of action. Some pesticides are very acutely toxic in humans, while others have low acute toxicity but may cause long term health effects in chronically exposed individuals. Each pesticide class has to be considered individually when predicting effects. Therefore, considering organochlorine pesticides induced disruption of body functions and possibly the involvement of free radicals is cardinal to present study.

Summary

Stem cells are undifferentiated cells which have the potential to divide and multiply indefinitely and can be differentiated to any type of cell of the body of an organism. Due to its peculiar characteristics stem cells are being experimentally used to cure certain dreaded diseases of the humans including different haemoglobinopathies. The stem cells isolated from bone marrow have been cultured, modified and differentiated to get various blood cells like erythrocytes, leukocytes, and thrombocytes etc. Recently haematopoietic stem cells have been transplanted to the sickle cell and beta thalassaemia patients successfully. Gene therapy using the embryonic and cord blood stem cells have been experimentally tried successfully to cure transgenic sickle as well as thalassaemic mice. Induced Pluripotent stem cells (iPS) generated from autologous skin has also been used successfully for treatment of transgenic sickle cell anaemia mouse.

Summary

Multicellular organisms are made up of diverse set of cells. Cells respond to the changes in the particular microenvironment by means of cellular communication. This cell-cell communication is extremely important for the development, maintenance and survival of the organism. This communication is equally important for the unicellular organisms. Cells communicate to one another and respond to the environmental changes using diverse chemical languages, as discussed in this chapter. However, in many cases like multicellular organisms, cell communication is primarily mediated by specific receptor(s) expressed on the cell membranes. These receptors bind to the extracellular signaling molecules (called ligands) and activate specific signaling pathways to bring about particular cellular responses. These different receptors, ligands and signaling pathways are briefly discussed here.

Summary

Animal tissue culture is a biological technique in which a piece of tissue is taken from an animal specimen and cells from this tissue are grown and maintained in an in vitro or artificial environment (Harrison, 1907). Aim of cell / tissue culture is actually to make cells as happy in the in vitro conditions, as they are in their natural environment. The objective of this chapter is to highlight those principles and procedures that have particular relevance to the use of cell culture in tissue engineering.

Summary

Idealistic theories of property are projected to offer general and explicit statements of the justification for deciding legal and moral questions about the status property claims. Debates over property rights in biotechnology were occasioned by specific legislative proposals such as the US Animal Patent Act of 1986, and by filing of patent applications for DNA sequences and processes in the early 1990s. While these debates make sporadic petition to philosophical theories of property, moral claims were entwined with questions about filing requirements, tests for worth, and the rules for licensing and defending patents. The comparative scarcity of discussion on intellectual property at that time dictated the general approach of the chapter: Review basic philosophical approaches to property rights, and speculate on how one might use these approaches in constructing an argument pertinent to agricultural biotechnology. This chapter deals with different approaches to intellectual property in the field of Plant Sciences especially the Biotechnology. It incorporate many different types of intellectual property and a variety of incommensurable values play a role in the justification of intellectual property.

Summary

Bioenergy is the subject of increasing attention around the globe and represents an important issue in the present context. The rise of commodities prices, the negative impact on food security, and climate change represent different challenges to be overcome before the full potential of bioenergy can be realized. Bioenergy issues related to agriculture needs special attention for its development. Bioenergy development is always linked with rural economy. Farmers, having the choice to convert their food crops to fuels crops, naturally expect a high return from their farmland, thereby generating a scenario where food production gets depleted. The optimal production of bioenergy can be generated by using the wasteland present in different area. This way, food security for the future generation can be maintained along with optimal growth of bioenergy.

Summary

Over the past several decades, the exponential population and social civilization expansion have been accompanied by rapid industrialization. As such, there has also been a proportionate expansion in the global energy demand. Till date, crude oil has been the only source to meet the increasing energy demand. Nowadays ethanol is the most acceptable product in the fuel market. The importance of ethanol is increasing due to a number of reasons such as global warming and climate change, limited reserves of fossil fuel and reduction on imports of transport fuel. Lignocellulosic biomass is an abundant renewable source for commercial alternative fuel. Maximum bioethanol production depends on the whole process and optimum process parameters itself. Bioethanol from lignocellulosics is a type of second generation biofuel. Many researchers have been focused on bioethanol production from renewable sources. This chapter highlights the processing steps for second generation bioethanol production from lignocellulosics.

Summary

The huge accumulation of agro-industrial waste-materials generated by the milling, brewing and various agriculture and food based industries which in total amount to be about 500 million tones per year in India. Most of these by-products contain three major structural polymers such as cellulose, hemicellulose and lignin. These are also the main source of feed for domestic animals. A high proportion of this waste material is carbohydrate and phenolic compounds. Accumulation of this kind of biomass not only results in the deterioration of the environment, but also loss of potentially important materials. Biological degradation, now-a-days, has become an increasingly popular alternative for the treatment of agricultural, industrial, organic as well as toxic wastes. Cellulose and hemicellulose being the major constituents of these materials can be referred to as valuable resources for a number of reasons, mainly due to the fact that they can be bio-converted easily into valuable products. These wastes can be processed to yield a number of value added products, such as biofuels like biohydrogen, bioethanol along with a variety of chemicals. Various treatment methods such as physical, chemical, biological are employed for the production of value-added compounds. Various phenolics like ferulic acid and vanillin are world’s most prized flavor compound mostly obtained through microbial treatment of agro-wastes.

Summary
 
Although the concept of IPM, with emphasis on minimum use of pesticides: is well established and widely practiced in India, pest population still continue to be unabated, often reaching to alarming levels .Development of non chemical methods of pest control  as component of IPM tactics is a priority area of research today. Development of multiple resistance in larval stages against recommended insecticides ,spoiling of crop ecosystem with toxic chemicals and consequences of health hazards is the best alternative to control the pest in adult stage before they reproduce. Use of light trap is one such potential methods of control for the species known to be positively phototropic in adult stage. Rice is one of the most important cereal crop grown in different parts of world , serving as staple diet for millions of people . The losses due to insect pests in rice are very high and the pesticidal use in this crop is second highest after cotton in world .The positive feature of using light trap as IPM tool for survey ,monitoring , detection and control tool is that most of the insect pest species of rice are phototropic in nature and collected in sufficient numbers in light trap .Therefore use of light trap for imparting eco-integrity  by minimizing indiscriminate use of chemicals ,reduction of pest management cost and enhancement of farm income can be very useful for achieving the ultimate goal of sustainability in rice cultivation. 

Summary

Molecular farming is the large scale production of pharmaceutically important and commercially valuable proteins in plants and animals. Molecular farming in plants has the potential to provide an inexpensive and convenient system in the production of unlimited quantities of recombinant proteins for use as therapeutics, diagnostics, vaccines, antibodies, plasma proteins, cytokines and growth factors. Plants are also being used for the production of oils, starches, plastics, enzymes for food processing and other uses and spider silk etc. However, quality and safety of the final product and wider effects of molecular farming on health and environment need to be addressed. The benefits of molecular farming should not be outweighed by risks to human health and environment.

Summary

Genetic engineering can be used to introduce specific traits into plants. It may not replace conventional breeding but can add to the efficiency of crop improvement. It is possible due to the fact that plants are totipotent, enabling regeneration of a new plant from an isolated cell. Transformation of dicots is usually carried out using the bacterium, Agrobacterium tumefaciens. Genes are cloned into plant expression vectors that carry the 25-bp repeat sequences at the borders of the onc region, known as the left and right borders (LB and RB) and the virulence genes (vir) of the Ti plasmid.

Summary

Expressed sequence tags are small pieces of DNA sequence (usually 200 to 500 nucleotides long) that are generated by sequencing either one or both ends of an expressed gene. Currently various EST sequencing projects are underway for numerous organisms, generating millions of short, single-pass nucleotide sequence reads, accumulating in EST databases. Extensive computational strategies and various databases have been developed to organize and analyse both small- and large-scale EST data for gene discovery, functional annotation of putative gene products as well as transcript and single nucleotide polymorphism analysis. Present chapter provides an overview of the significance of ESTs, their properties, databases, analysis software and the applications of ESTs.

Summary

Genes are discrete elements that govern the appearance of specific traits. Morgan Sturtevant and their coworkers demonstrated that genes have specific address. They reside at particular locations on particular chromosomes and these addresses remain constant from one individual of the species to the next. Transcription is the first step leading to gene expression. It is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes. During transcription, a DNA sequence is read by RNA polymerase, which produces a complementary, antiparallel RNA strand. translation is the second stage of protein biosynthesis (part of the overall process of gene expression). In translation, messenger RNA (mRNA) produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide, that will later fold into an active protein.

Summary

Metagenomics is a rapidly developing field of research that enables the study of microbes that have not been cultured or cannot be cultured easily. It has greatly advanced the understanding of ecology and diversity of natural microbial communities and has led to the discovery of many new genes and geneproducts. The various aspects of metagenomics – history, techniques for identification, different approaches of data analysis, comparative and functional genomics, applications in the areas of medicine, agriculture, biotechnology, ecology, bioprospecting, bioremediation, future advances and challenges and issues related to intellectual property, have been discussed.

Summary

This review addresses various defense strategies evolved by plants to resist pathogen attack.Of the different defensive strategies, pathogen attack either induces or enhances constitutively the synthesis of a spectrum of diverse chemical compounds in various plant species. These chemical compounds also called secondary metabolites are classified broadly as nitrogen compounds, terpenoids and phenolics and have been documented to possess broad range antifungal, antimicrobial and pesticidal activities. Such defensive compounds could be extracted and developed as eco-friendly biopesticides/microbicides because of their natural occurrence, ephemeral nature and biodegradability. These will be favorable alternative strategies compared to chemical pesticides that are fraught with various harmful side effects.

Summary

Plant cell culture systems produce myriads of valuable compounds which cannot be synthesized by microbial cells or chemical synthesis. Many of the drugs sold today are simple synthetic modifications or copies of the naturally obtained substances. The burgeoning demand for secondary metabolites in recent years as therapeutic agent has resulted in a great interest, in secondary metabolism, and particularly in the possibility to alter the production of bioactive compounds using cell culture technology. Various strategies such as cell line selection, use of precursors and elicitors, mass culture in bioreactors and others have proved effective in enhancing the production of these metabolites so as to meet the market demand but space for improvement still exists. In order to stretch the boundary, recent advances, new directions and opportunities in plant cell based processes are being examined in this section.

Summary

Synthetic seed technology is an alternative to traditional micropropagation for the production and delivery of cloned plantlets. Several aspects of the technique are still underdeveloped and hinder its commercial application. This technology may be of greater value in breeding programs and allows the propagation of many elite genotype-derived plants in a short time and would provide an easy and novel propagation system for the elite as well as difficult to root species. Also, encapsulation of propagules that were produced in vitro could reduce the cost of micropropagation of plantlets for commercialization and final delivery to the farmer field. This technology also employed for germplasm storage and exchange purposes.

Summary

Human activities involving rapid industrialization and urbanization without concomitant environmental planning have resulted in a situation where substantial parts of our land and water resources have been polluted with organic and inorganic toxicants.  Environmental engineering principles have been utilized to detoxify polluted areas; however, the efforts, adopting predominantly physico-chemical methods, have addressed the issue to a restricted extent, focusing on solutions for specific categories of pollutants and applicable for limited areas, in addition to being expensive. Hence cost-effective sustainable alternatives in the form of bioremediation (involving microorganisms) and phytoremediation (involving plants alone or along with associated rhizospheric microorganisms) are gaining public acceptance. Considerable scientific evidence has proved that many plant species can detoxify the pollutants utilizing various mechanisms. In this background, in vitro plant cultures have served as invaluable tools in identifying appropriate plant species for phytoremediation. Better understanding of the complex interactions underlying phytoremediation has been facilitated using in vitro cultures where the only variable is the pollutant, in contrast to field experiments where there are many confounding variables. While straightforward extrapolation of in vitro data can be erroneous, these systems provide the basic framework for translating laboratory-scale experiments to field-scale technologies.

Summary

Tropical forests are declining sharply and continuously growing demand of wood leads to removal of trees from their natural habitats. Clonal propagation of superior trees is must for further exploration and conservation of these genetic resource. Tissue culture technique offers rapid and large scale propagation of desired traits. However, micropropagation of adult trees is difficult; many problems are associated like- maturity, contamination, phenolic leaching, season, variants, long life cycle, etc. Shoot bud culture is the easiest and successful tissue culture technique for the toughest material to clone- mature trees. The chapter deals with the bud culture method of heartwoods and associated problems at different stages – explant establishment, shoot multiplication, rooting and acclimatization. Also the possible solutions of the problems are discussed on the basis of previous reports.

Summary

Plant tissue culture is the technique of growing plant cells, tissues or organs in isolated from the mother plant on artificial media. It has opened up unprecedented opportunities in many areas of basic and applied biological research. This includes techniques and methods used to research into many botanical disciplines and has several practical objectives of plant tissue culture and micropropagation for sustainable development. Indeed, the landmark publication by Gottlieb Haberlandt who is arguably referred to as the “Father of Tissue Culture”, is often cited as the origin and emergence of plant tissue culture and its subsequent applications. Success of biotechnological approaches is dependent on regeneration of intact plants following genetic modification, generally by micropropagation. Potential uses of plant tissue culture in biotechnology to further our understanding of plant physiology, how plants function, resolution and expression of use full characters form in vitro to in vivo condition. Agro bacterium-mediated genetic transformation along with other modes of transformation such as microprojectile bombardment has been accomplished mainly through plant tissue culture.

Microbial inoculants in agriculture, horticulture and forestry can be defined as preparations containing strains of microorganisms which can augment the microbiological process such as nitrogen fixation, phosphate mobilization, excretion of growth promoting substances, decomposition of organic wastes, biocontrol of insect pests and diseases etc. Thus they become an important component of sustainable agriculture. Microbial inoculants are based on renewable sources available in soil and nature and are low cost input and eco-friendly. These inoculants carrying the microorganisms when applied to soil/plant promote plant growth and productivity.

Sustainable agriculture or organic farming wherein biological inputs are maximum and chemical inputs are minimal, is drawing the attention of farmers across the world including India. For replacing chemical fertilizers, which supply plant nutrients by organic manure, the basic requirement is the availability of raw material i.e. the organic matter or biomass that can be decomposed to organic manure. The question that is often asked is what are the different sources of available biomass and how much of it is available? Different sources of biomass can be categorized as

Herbicides are the chemical substances used to kill weeds, i.e., unwanted plants that compete with crop plants for soil nutrients. Chemical herbicides are the most effective immediate solution to most weed problems. Use of chemicals, however, can be harmful to wildlife, to the environment and to humans. Chemicals are also expensive, and weeds develop resistance to the chemicals. For these reasons, there is now a move toward alternative methods of controlling the weeds. One of the most promising is biological weed control, which involves using one living organism to control the activities of another organism.

The adoption of modern agricultural technologies has culminated into serious problems of pesticide resistance in major pests, resurgence in minor pests, elimination of populations of natural parasites, predators and pollinators, environmental pollution, pesticide residues in food chain and health hazards. World Health Organization (WHO) estimates one million pesticides poisoning cases and 20,000 deaths every year globally. This is due to high pesticide residues in food chain including cereals, pulses, vegetables, fruits, milk and milk products (including mother’s milk), fishes, poultry, meat products and water. Twenty five per cent of Indian food products contain pesticide residues above tolerance level compared to only 1.2% globally.

Emphasis of present day agriculture is to produce more with lesser land, water and man power. Apart from natural calamities like drought, flood etc., biotic stresses like pests, diseases and weeds also influence the crop productivity greatly. Sixty to eighty per cent of the total crop losses are attributed to the devastations caused by pests and diseases. Farmer’s income in recent years is decreasing gradually due to increased cost of inputs particularly in plant protection. The excessive dependence on chemical pesticides leads to the development of resistance in insect pests and pathogens, out breaks of secondary pests and pathogens / biotypes and occurrence of residues in food chain. To avoid this situation the concept of Integrated Pest Management (IPM)/ Integrated Disease Management (IDM) approach should be considered on top priority.

The rhizosphere is the narrow zone of soil surrounding the root that is under the immediate influence of the root system. This zone is rich in nutrients when compared with the bulk soil, due to the accumulation of a variety of organic compounds released from roots by exudation, secretion and deposition. Organic compounds released by plant roots include amino acids, fatty acids, nucleotides, organic acids, phenolics, plant growth regulators, putrescine, sterols, sugars and vitamins. Because these organic compounds can be used as carbon and energy source by microorganisms, microbial growth and activity is particularly intense in the rhizosphere.

Phosphorus is one of the essential nutrients for plant growth. It is an integral part of the cellular activities of the living organisms. It has a defined role in plant metabolism such as cell division, development, photosynthesis, break down of sugar, nutrient transport within the plant, transfer of genetic characteristics from one generation to another and regulation of metabolic pathways. Phosphorus is a frequently limiting macronutrient next only to nitrogen for plant growth and makes up about 0.2% of plant dry weight. The plants obtain their P requirement from the soil pool. It occurs in soil as inorganic phosphates, produced by weathering of parent rock or as organic phosphate derived from decayed plant, animal, or microorganisms.

Nitrogen is the most important element on which depends growth and productivity of plants. It is also the most abundant molecule in the atmosphere (80%), yet it cannot be utilized by plants. The plant utilizable form of nitrogen is either, its most oxidized form, the nitrates or the most reduced state, the ammonia.  The indiscriminate use of nitrogenous fertilizers amounts to depletion of non-renewable fossil fuels used in fertilizer production. Sustainable agriculture depends largely on renewable resources and on-farm nitrogen contributions are achieved largely through biological nitrogen fixation (BNF), which helps in maintaining and/or improving soil fertility by using atmospheric nitrogen. Annually BNF is estimated to be around 175 million tonnes of which close to 79% is accounted for by terrestrial fixation.

The term soil refers to the outer, loose material of the earth’s surface, a layer distinctly different from the underlying parent rock. A number of features characterize this region of the earth’s crust. It is the natural medium, which supports plant growth. It provides the physical support needed for the root system and also supplies nutrients needed for plant growth. It is a perennial source of organic matter. It supports a vast population of microorganisms.

Biotechnology plays a very important role in agriculture as a result of its ability to modify microorganisms, plants, animals, and agricultural processes. The umbrella of microbial technology in agriculture covers numerous scientific activities, ranging from production of biofertilizers to that of microbial pesticides; from biological nitrogen fixation to lignocellulose degradation; from production of biomass and biofuels to transgenic plants. Terrestrial ecosystem contains an important dynamic living matrix termed soil, which is critical for agricultural production and food security. Soil forms the medium for growth and maintenance of a variety of plant species. Soil is considered a store house of microbial activity, though the space occupied by living microorganisms is estimated to be less than 5% of total space.

Abstract

Microbiological synthesis of nanoparticles has emerged as rapidly developing research area in nanotechnology across the globe with various biological entities being employed in production of nanoparticles constantly forming an impute alternative for conventional methods. Simple prokaryotes to complex eukaryotic organisms including higher plants are used for the fabrication of nanoparticles. In the present article, the synthesis of important plant nutrients like Mg, Zn, Ag, Au, Ti, P and Fe nanoparticles from different fungal species, their characterization and application potential of nanonutrients in agriculture is elaborately discussed.

Abstract

Microorganisms inhabiting in the rhizosphere play a vital role in ecosystem functioning. Rhizosphere is an area around the root surface where pathogenic and beneficial microorganisms repose and influence the plant growth and health. These microbial groups of bioagents found in the rhizosphere include bacteria, fungi, nematodes, protozoa, algae and micro-arthropods. Because of their rich diversity, complexity of interactions and numerous metabolic pathways, microbes are an amazing resource for biological activity. These microorganisms require organic matter for their growth and activity in soil and provide valuable nutrients to the plants and hence maintaining the plant health. The most promising fields for the use of bioinoculants are agriculture, horticulture and forestry. There are many reports on the inoculation of bioagents in agriculture and horticulture crops but only a few reports are available in forestry. This article is an overview on various bioinoculants which are used during inoculation and a compilation of scattered reports of bioinoculants in forestry only.

Abstract

Amongst various oilseed crops grown across the world, soybean (Glycine max L. Merrill) is globally important as a high source of protein and oil for human consumption and is also being used as potential feed for animals. Soybean is grown under rain-fed conditions in the tropics and subtropics in the marginal lands with less amount of external application of chemical fertilizers. The frequent climate variations have created a number of biotic and abiotic stresses, drought being a major abiotic stress which adversely affects the soybean productivity. Thus, to enhance the productivity of soybean, besides managing the nutrients, stress management is of utmost importance. There is a great opportunity of application of microbes especially arbuscular mycorrhizal fungi (AMF) where its application alone or in combination with plant growth promoting rhizobacteria (PGPR) can help in nutrient mobilization and remediation of plant stresses.

Abstract

Soil salinization is an important factor limiting crop production, mainly in the arid and semiarid regions of the world. Nevertheless, plants naturally have evolved several physiological, biochemical and molecular mechanisms to establish and thrive in salt stressed soils. In addition to breeding crops for salt tolerance, recent emphasis is on exploring the possible role of plant-microbe interactions in amelioration of salt stress in plants. It is now well established that arbuscular mycorrhizal (AM) symbiosis alleviates the effect of salt stress in plants. Further, available evidence does suggest that AM symbiosis regulates many of the plant’s salt stress alleviation mechanisms. However, the molecular basis for many of these mechanisms is yet to be ascertained. In this chapter, we summarize the current knowledge on the role of AM symbiosis in alleviation of salt stress in crop plants, which now appears to be a promising strategy to improve crop yield in salt stressed soils.

Abstract

Abiotic stresses lead to the overproduction of reactive oxygen species (ROS) in plants which are highly reactive and toxic and cause damage to proteins, lipids, carbohydrates and DNA which ultimately results in oxidative stress. The arbuscular mycorrhizal fungi (AMF)-symbiosis can confer a greater degree of tolerance against drought stress in many cash crops. The significance of heat shock proteins (Hsps) and chaperones in abiotic stress responses in plants, and co-operation among their different classes and their interactions with other stress-induced components is well known. Soil salinity is a major abiotic stress adversely affecting plant growth and crop production worldwide. Phyto-mycoremediation utilizing AMF as plant inoculants is regarded as a promising strategy to heavy metal pollution remediation. Plants have stress specific adaptive responses as well as responses which protect the plants from more than one environmental stress. The potential of phytoremediation of contaminated soil can be enhanced by inoculating hyper-accumulator plants with mycorrhizal fungi most appropriate for the contaminated site.

Abstract

Drought and salinity are two major abiotic stresses that affect various aspects of human lives of one third world population including human health and agricultural productivity. Abiotic stresses such as salinity, drought, nutrient deficiency or toxicity, and flooding limit crop productivity world-wide. A living organism is considered resistant if it tolerates a given physicochemical stress. The presence of microorganisms within the soil, specially a main group known as arbuscular mycorrhizal fungi (AMF), is a key factor in the adaptation of plants to the different ecosystems. The AMF colonizing within the plant roots can determine the success of plants in salt- and/or drought-affected areas. The symbiosis with AMF has been proposed as one of the mechanisms of salinity and water stress avoidance. Studies have shown greater drought and salinity tolerance in AMF-colonized plants by a number of mechanisms. These mechanisms include enhanced water and nutrient uptake directly by extraradical hyphae, higher leaf stomatal conductance and/or better root system architecture, higher capacity of osmotic adjustment and antioxidant defense systems, better soil structure due to higher glomalin and over expression of genes encoding antioxidant enzymes.

Abstract

A majority of the plants studied in natural ecosystems are symbiotic with microorganisms that either reside entirely (endophytes) or partially within plants. These microorganisms express different associations ranging from mutualism to parasitism. These symbiotic relationships appear to impart tolerance to various types of abiotic stresses such as heat, drought, salinity, heavy metals, etc. and sometimes may be responsible for the survival of both plant hosts and microbial symbionts in high stress habitats. The amelioration of the abiotic stresses by the endophytes assumes increasing significance in the light of rapidly changing global climate, which is likely to face frequent incidences of extreme weather conditions like high temperature, droughts, etc.