eChapters

Abstract

Increases in atmospheric concentrations of CO₂ are likely to have major physiological consequences for plants, due to the major effects of atmospheric CO₂ on photosynthetic rates and the centrality of photosynthesis to plant metabolism. We review what is known about the effects of growth at elevated levels of CO₂ on the protein and N concentrations of plants in general, and food crops in particular. Growth at elevated CO₂ typically reduces plant tissue N concentrations by 10-15%. The physiological mechanisms behind this decrease in tissue protein and N are likely complex, and include both dilution from increased tissue concentrations of non-structural carbohydrates and decreased root uptake of N.

Abstract

Nitrogen is the most limiting nutrient controlling production of all agricultural systems. Application of N fertilizer has increased food production tremendously all over the world. However, it also contributes towards global warming and ozone layer depletion through emission of nitrous oxide, a greenhouse gas (GHG). Therefore, there is a need to assess the possibilities of N management for climate change abatement and food security enhancement, while minimizing environmental and human health impacts. In this chapter, role of gaseous-N emission on N use and various mitigation options for Indian agriculture have been discussed. For the base year 2007, the direct and indirect N₂O emissions from Indian agricultural soils was estimated to be 136.29 Gg (35.3 Tg CO₂ equivalent) and 30.61 Gg (5.8 Tg CO₂ equivalent), respectively.

Pigeonpea (Cajanus cajan L. Millsp.) is crowned as poor man’s crop which provides much needed protein to farming families with least inputs. It is a versatile plant species which can grow successfully in a range of soil types, temperatures and photoperiods. Its deep root system enables it to overcome intermittent drought and other stresses. In India, the crop is grown annually on about 4.04 m ha (FAO, 2012) and the major pigeonpea growing states are Maharashtra, Andhra Pradesh, Karnataka, Madhya Pradesh, Uttar Pradesh, Bihar and Gujarat (Table 1). The high protein pigeonpea dal (decorticated dry splits) is widely consumed across the country in various cuisines. The annual national production of pigeonpea is about 2.56 m tones. This produce, however, is not sufficient to feed the ever growing population of the country, and hence, necessitates huge (500,000 tons) imports of this pulse. In spite of its importance in food security and sincere research efforts, its national productivity could never cross the bar of 800 kg/ha (Fig 1) since independence. Since last 50 years, ICAR has been very seriously pursuing the issue of genetic enhancement with huge investments and some out-standing pure line varieties with about 10% more grains over the best local varieties were developed.

Male sterility is a situation where the male reproductive parts of a plant are either absent, aborted, or non-functional; and therefore, they fail to participate in the process of natural sexual reproduction. This situation generally arises due to some developmental defect that occurs at any stage of microsporogenesis (process of development or release of pollen grains) in the plants. Since male sterility is the manifestation of abnormal growth and development and can occur at any point of time, the action of genes controlling male sterility is also be variable and inconsistent across the genotypes. Based on the type of malfunctioning of androecium, the male sterility systems have been classified as structural (absence or deformity of anthers), sporogenous (defective microsporogenesis), and functional (failure of mature pollen to germinate). In addition, on the basis of genetic control mechanism of the male sterility, it has also been classified as genetic, cytoplasmic, and cytoplasmic nuclear (or genetic) male sterility. With respect to utilization of male sterility in crop breeding, it is essential that individuals with altered male fertility keep their female fertility intact. The fertilization of such plants takes place with pollen grains from other plant that is transferred with the help of external agencies such as wind, insects, or human beings.

3.1. Natural cross-pollination

Breeding procedures in any plant species of economic importance are guided by its reproductive system particularly, pollination mechanism. In the cereal crops such as maize, pearl millet etc., where cross-pollination is facilitated by wind, the breeders have developed schemes for commercial exploitation of dominance and epistatic genetic variation through hybrid and population breeding. In contrast in self-pollinated crops, the efforts are always made to exploit additive genetic variation primarily through pedigree and mass selection.
 
In pulses, self-pollination is a rule and pigeonpea is no exception. However under field conditions, occurrence of hybrid plants in the populations is not uncommon; and it happens due to some degree of natural out-crossing that took place in the preceding generation. This type of partial natural out-crossing in pigeonpea is affected by a variety of insects (Fig 10) which forage on its large flowers to collect the nectar. These minor incidences of out-crossing are the primary source of varietal deterioration. Recently, the pigeonpea breeders converted this constraint into an opportunity for genetic enhancement of yield through exploitation of hybrid vigor and developing commercial hybrids.

4.1. Flower and flowering in pigeonpea

Growth habit: Primarily, there are two major growth types in pigeonpea. These are determinate and non-determinate. The determinate growth in the pigeonpea plants is characterized by flowers in bunches at the top of the canopy (Fig 17a). In this case the epical growing points are transformed in to reproductive buds and bunches of flowers appear on the top of the canopy. Such cultivars are not popular as the management of insects such as Helicoverpa and Maruca becomes very difficult. Most of the cultivated types belong to another growth category called as non-determinate. In such genotypes the apical growing points remain vegetative and the plants keep growing under favorable conditions and it results in tall canopy with many spreading or compact branches. The inflorescence in this case emerges from the axil of secondary and tertiary branches (Fig 17b); and hang sideways. These types show less susceptibility to insects due to non-clustering nature of flowers.

5.1 Seed back up programs

In hybrid breeding program, testing of new hybrid combinations is a continuous process and in most cases, the availability of crossed (hybrid) seed for their annual evaluation of selected hybrids is an important issue. Since, the selection of hybrids for advancement is based on yield data, one year will be required to produce seed for testing in the subsequent season. This means for each cycle of advancement, one valuable season will be consumed in their seed production. To avoid this situation and enhance the testing program at a fast pace, an aggressive hybrid seed production program should be followed. This can be achieved by visually selecting relatively more number of hybrids based on their flowering time, plant vigor, disease resistance, and early pod load about 4-5 weeks before harvesting. During this period, the new seed of the selected hybrids can be produced manually. This operation is facilitated by the perennial nature of pigeonpea plant, which can flower for extended periods of 40-50 days; that allows completion of desired number of pollinations of the target crosses in the same cropping season. One trained person can pollinate about 300 buds in 6-7 hours; and with 20% success, about 150 seeds can be produced. Experience has shown that, with good planning and crop management, this program can be achieved with ease.

Fig. 25: ICPH 2671 in field

To overcome the challenge of popularizing pigeonpea hybrids in the country, it is considered fair enough to compare the hybrid rice with respect to their seed production technology, yield advantages and profitability to the farmers and seed producers. Since both pigeonpea and rice are grouped under self-pollinated crops, this comparison, in the views of authors, may help in encouraging hybrid pigeonpea seed producers and those involved in marketing of hybrid seed.
  
Rice is a highly self-pollinated crop and earlier hybrids were not possible because it was essential that large quantities of hybrid seeds are produced easily and economically. In China, the birth place of hybrid rice, this impossible looking task was accomplished. To launch this program, the Chinese scientists decided to alter the pollination system of rice.

With the advent of hybrid technology, it is natural to assess its potential benefits at the national level. To meet the domestic requirement of pigeonpea, about 50.000–60,000 metric tons of pigeonpea is imported annually from Myanmar and Africa. In this communication, an attempt has been made to look into the possibility if we can meet the entire domestic needs of pigeonpea through the adoption of hybrid technology. It is a big question but the goal is not impossible. The estimates shown in Table 18 show that if only 2% of total pigeonpea area can be brought under hybrids, the target can be met with ease. This will require seed production in only 700-800 hectares.

The hybrid breeding program in pigeonpea is unique and the first among the food legume. The concept of hybrid in this crop was conceived in 1974; and it is based on a small window of natural out-crossing present in the crop. This natural out-crossing in pigeonpea is mediated by a range of flying insects, which forage on large bright colored flowers of the crop in search of nectar and in the process affect the cross-fertilization. In the last 40 years a lot of basic and applied research has been successfully completed and over 50 research papers have been published in national and international journals of repute. A coordinated effort of scientists of different institutions has led to the release of two hybrids, one for central and another for peninsular zone of India.

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.

Introduction

This section of the manual contains instructions for preparing stock solutions that are commonly used in laboratory protocols for the analysis of DNA, RNA and proteins and visualization of gene or protein expression. Each of these stock solutions is provided as either the most convenient concentration or the most frequently used stock concentrations to be used in the protocols of an individual laboratory.

All chemicals must be reagent grade or molecular biology grade, and the water used in the preparation of all solutions must be the highest quality available. Use sterile-glass distilled deionised water whenever possible. Unless otherwise stated, most solutions required sterilization either by filtration or autoclaving.

Plant cell culture
Introduction

As the human population is expanding there has been increasing concern over whether current rates of food productions can support the growing population. In response to the increasing demand, scientists and farmers have been working hard to come up with new ideas to meet these needs. These ideas range from simple procedures including selection of the best seeds to more complex procedures requiring the transplantation of genes into different plant species. This chapter focuses on one of the important aspects of plant science which is the growth of plant cells in an artificial media. This process is known as plant cell culture and can be applied in many different ways. 

DNA Isolation Protocol
Introduction

Most of the all procedures involved in molecular biology experiments require the purified form of nucleic acid. It forms a fundamental requirements for genome characterization, gene mapping and for identification and isolation of gene for genetic engineering. The most important step involved in removal of proteins which is carried out in different ways. The following protocol is one of the most commonly used protocols in animal, plant and microbial samples.

Introduction

In order to use a fine quality of DNA for various molecular biological work like sequencing, cDNA synthesis and cloning, RNA transcription, transfection, nucleic acid labeling (random primer labeling), etc., quality and quantity of DNA is extremely important to have the defined template concentration. Failure to produce results from the above techniques can sometimes be attributed to an incorrect estimate of the DNA template used.

Introduction

This chapter gives first hand information on PCR for beginners. PCR is used to amplify a short, well-defined part of a DNA strand. This can be a single gene, or just a part of a gene. As opposed to living organisms, the PCR process can copy only short DNA fragments; usually up to 10 kb (kb stands for kilo base pairs). Certain methods can copy fragments up to 40 kb in size, which is still much less than the chromosomal DNA of a eukaryotic cell-for example, a human cell contains about three billion base pairs (Kary Mullis, 1983).

Introduction

Gel electrophoresis is a technique for separating charged molecules with different sizes. Two kinds of gels are commonly used: agarose and polyacrylamide. Agarose gels can be applied to a wider range of sizes than polyacrylamide gels.  By using standard agarose electrophoresis, nuclei acids up to 50 kb may be separated. If Pulsed Field Gel Electrophoresis is used, the upper limit can be extended to 10 Mb. Polyacrylamide gels may separate nucleic acids that differ in length by only 1 nucleotide if their length is less than 500 bp (Sambrook et al., 1989).

Introduction

Restriction enzymes, recognizes specific base sequences in double-helical DNA and cleaves at specific places, both strands of a duplex containing the recognized sequences. To biochemists, these exquisitely precise scalpels are marvelous gifts of nature. They are indispensable for analyzing chromosome structure, sequencing very long DNA molecules, isolating genes, and creating new DNA molecules that can be cloned. Werner Arber and Hamilton Smith discovered restriction enzymes, and Daniel Nathans pioneered their use in the late 1960s.

Southern Blotting
Introduction

Southern hybridization was named after Edward M. Southern who developed this procedure at Edinburgh University in the 1970s. To oversimplify, DNA molecules are transferred from an agarose gel onto a membrane. Southern blotting is designed to locate a particular sequence of DNA within a complex mixture. It is also called Southern blotting since the procedure for transfer of DNA from the gel to the nitrocellulose filter resembles blotting. In Southern hybridization, a sample of DNA containing fragments of different sizes is subjected to electrophoresis using either polyacrylamide or agarose gel.

Introduction

Only after the discovery of restriction endonucleases it became possible to digest any DNA molecule at a specific site and any two pieces of DNA could be joined together with the help of another modifying enzyme, the DNA ligase. Consequently, a new branch of molecular biology, namely genetic engineering has been developed. With the help of genetic engineering techniques, it is now possible to identify and isolate the gene (for a protein of interest and insert it into the genome of another organism with the help of a suitable vehicle. The foreign gene thus cloned, can be amplified to produce millions of its copies. The insert gene can be expressed by the host to synthesize the gene product. The technique can also be used for understanding the regulation of expression of the cloned gene. The possibilities are endless and probably sky is the only limit. In this chapter we will briefly discuss the basic principles and protocol involved in gene cloning.

Introduction

DNA sequencing is the process of determining the nucleotide order of a given DNA fragment. The most commonly used sequencing method is the dideoxy method. This method uses dideoxynucleotide triphosphates (ddNTPs) which have an H on the 3’ carbon of the ribose sugar instead of the normal OH found in deoxynucleotide triphosphates (dNTPs). Dideoxynucleotides are chain terminators. In a synthesis reaction, if a dideoxynucleotide is added instead of the normal deoxynucleotide, the synthesis stops at that point because the 3’OH necessary for the addition of the next nucleotide is absent (Sanger et al., 1977).

ABSTRACT

Concomitant with paradigm shift from agrarian and brick and mortar economy to knowledge and service based economy, India needs to adhere to the international conventions for the benefit of enriching its knowledgebase with which economic development and social welfare could be achieved. Although geoscientific research has been at the forefront and contributed immensely to our country’s economic development, number of applications for patents, copyrights, etc., on geoscientific concepts, databases, innovations, designs or processes has been negligible when compared with other branches of science. This paper intends drawing the attention of geoscientists on this lacuna and provides information on fundamental aspects of IPR that may be of help to geoscientists whose innovations are waiting to be filed for patents or copyright.

ABSTRACT

The law of intellectual property has assumed utmost importance the World over, in the recent past and it is being considered as one of the most important subjects of law in view of its implications on economic, social and cultural realms. The term “intellectual property” has come to be internationally recognized as covering, patents, industrial designs, copyrights, trademarks, know-how and confidential information or trade secrets. This paper presents an overview on nature and scope of these elements of IPR.

ABSTRACT

This paper provides an overview on existing IP protection and registration systems of India and adds information culled from publicly available sources pertaining to modernization efforts of Government of India towards establishment of foolproof IP protection in accordance with international treaties, conventions and bilateral and multilateral agreements.

ABSTRACT

This paper presents an outline on the patenting system prevailing in India. 

INTRODUCTION

Ideas and knowledge are increasingly important parts of trade. Most of the value of new medicines and other high technology products lies in the amount of invention, innovation, research, design and testing involved. Hence, protection of such values is paramount. This paper details how these values are protected in India.

Abstract

Intellectual property right (IPR) is the most serious, new branch of law and a legal right conferred by federal government in accordance with International conventions and treaties. IPR protects some of the finer manifestations of human achievement. IPR safeguards the application of ideas and information that are of commercial value. The exploitable ideas become more sophisticated and hope for a successful economic future depends increasingly upon the superior corpus of new knowledge and fashionable conceits.  Copyright law is one of the effective tools of IPR. Copyright law provides an incentive to creative activity of author and permits the society to benefit from those inventions. However, the technological advancement has made violation of copyright very easy and regulation very difficult. This paper aims at familiarizing  copyright laws and the powers enshrined in copyright laws.

ABSTRACT

This paper provides an overall view on the history, structure and functions of World Intellectual Property Rights Organization.

Introduction

Human genius is the source of all works of art and invention. These works are the guarantees of a life worthy of men.  It is duty of the state to ensure with diligence the protection of the arts and inventions,” reads an inscription on the copula in the WIPO Headquarters building in Geneva. True to this inscription, WIPO functions through various mechanisms fostering judicious utilization of human intellect.  This paper intends presenting an overview on WIPO.

ABSTRACT

This paper provides an account on the origin of the concepts of IP, gradual development and their culmination at the TRIPS.

Introduction

Intellectual property rights form the most prominent and ever-expanding category of rights in the 21^st Century. It differs from other proprietary rights in many respects and prevails in most articles of law, which influence our daily life. The economic significance of intellectual property rights has made it a subject of global political interest. In the broader sense, the term “intellectual property rights” connotes different categories of rights such as patents, copyrights, trademarks, designs, plant varieties, semiconductors, geographical indications, trade secrets and data exclusivity with varying scope

ABSTRACT

This paper takes cues from the previous paper on the evolution of IPR concepts and attempts explaining the nuggets of TRIPS and analyzes the current trends in its implementation.

Introduction

As the TRIPS Agreement signifies stronger protection of conventional and new areas of intellectual property, the question that how implementation of TRIPS could influence developed and developing countries is to be addressed. The implications of such influence have far reaching consequences in terms of socio-economic development of Nation States, including geopolitical strategies and hence, a proper understanding on the plausible influence is essential.

ABSTRACT

This paper attempts to portray prevailing scenario of IPR in the light of globalization with special emphasis on harmonization of IPR systems and laws of different countries. 

INTRODUCTION

The globalization of information, facilitated by the Internet, has significant implications for intellectual property regimes of national and international levels. Assessment of these implications and their probable outcomes is unavoidably value-driven. Globalization represents ever-increasing influence of developed nations and transnational entities over developing and less developed nations. The process has also brought in significant changes in understandings of sovergenity. An analysis of the implications of globalization of information on international and domestic intellectual property rights and legal regimes is a complex endeavor.

ABSTRACT

This paper is an attempt to analyze the plausible impacts on the economy and social issues of developing countries with reference to enforcement of IPR.

Introduction

From commodity based nature, business has changed during the past hundred years in a way that ideas and knowledge have taken higher value than commodities. Today, many companies find their most valuable assets being intangible and they are therefore dependent on functioning IPR systems. But does the rigid protection of IPR serve all the people in our globalized world? The purpose of this paper is to discuss the impact of the introduction of IPR protection on developing and under developed countries in the light of TRIPS Agreement.

ABSTRACT

This paper discusses IPR concepts in the light of Indian culture and issues emanating from enforcement of those concepts in developing countries such as India.

INTRODUCTION

The adage “Knowledge is wealth” suits the present era well than any other period. India is known for its innovative thoughts since ages. However, it never monopolized the knowledge it possessed. In India, the knowledge of a person is thought to be utilized for the benefit of the society as an obligation of the knowledge holder. Does this mindset of Universal humanity (Vasudevo Kudumbagam) and common good (Sarva Sugino Bavandu) would benefit us in the materialistic society? This paper is an attempt to answer this query.

ABSTRACT

The concept and nature of intellectual property have undergone a paradigm shift during the last few decades. The importance of effective IPR governance has attracted the attention of its stakeholders. Hence, this paper focuses on the role of IPR governance and management practices for improving the quality of relationships among stakeholders besides documenting current and future trends of IPR governance and management.

INTELLECTUAL PROPERTY RIGHTS – AN INTRODUCTION

Intellectual property rights refer to the privileges granted by the government to any individual or organization for creative prowess. In recent years, such rights have gained immense importance. The laws in existence for protection and enforcement of these rights are meant to foster innovation and for regulating the use of inventions.

ABSTRACT

This paper is an attempt to draw the attention of readers of this volume to understand the importance of documentation and preservation of earth’s resources.  

Introduction

Earth has innumerable treasures that were and are being exploited by mankind. Geo-resources in the form of minerals, non-renewable hydrocarbons, paleontologic relics and related evidences indicate earth’s evolutionary history. Continuum of biological activity albeit varying rates of proliferation had resulted in accumulation of natural resources embedded in Earth and distributed at specific geographical niches. Biological perspective of earth history is significant in unraveling bio-geo-sphere interactions through geological time. Fossil records of invertebrates, vertebrates and plants are signals of major changes in earth’s evolutionary history. These constitute unparalleled windows to understand continental separation. Intercontinental and intra continental migration of living forms are also traced through fossil study.

ABSTRACT

This paper presents few measures to be taken up by academic institutions, professional societies, industrial bodies and governmental agencies for the propagation of information of IPR in terms of encouragement of publication of books on IPR, establishment of IPR cells in academic and professional institutions and making IPR education as part of curriculum in Universities and institutions of higher learning.

Abstract

Ever growing population and associated food scarcity are the major issues of concern globally. Microorganisms are the ultimate solution for addressing this severe problem in association with recent advances made in genomics and molecular biology. Many bacterial and fungal species which are in association with plant rhizosphere soil can immensely contribute in better growth and developments, ultimately leading to better yield. Exploring these novel organisms happens to be the need of an hour. Metagenomics and next generation sequencing technologies can contribute in identifying those microbes which are otherwise impossible to cultivate traditionally.

Abstract

The rhizomicrobiome plays a vital role in maintaining plant health and is highly influenced by the root exudates of the host plant. Plants select a subset of microbes at different stages of their development, and determine the microbiome community composition in its immediate vicinity presumably for specific functions. The rhizomicrobiome is composed of diversified microbial community with specific functions and is highly influenced by the plant type, soil type and environmental conditions. The rhizomicrobiome communities apart from promoting plant growth also elicit induced systemic tolerance to salinity and drought in stressed plants. Bacterial communities producing 1-aminocyclopropane-1-carboxylate (ACC) deaminase modulate stress ethylene in plants and alleviate the effects of abiotic stress and increases plant adaptability to stressed environment.

Abstract

With increasing population and subsequent human requirements; the generation of municipal solid waste (MSW) has increased all over the world. In India, the safe disposal of the municipal solid waste still remaines a problem for the authorities concerned. Depending upon the nature and type of the MSW, there are physical and chemical methods for the disposal of the waste, but these methods have their own limitations. Those limitations may be overcome by biological methods. Higher number of microorganisms are present in MSW which may either be pathogenic or nonpathogenic. These microorganisms may play a vital role in bioconversion of MSW into compost. The compost thus produced is useful in increasing soil fertility and reducing the concentration of the waste.

Abstract

Impact of climate change and related stresses on plant productivity are being witnessed worldwide with developing countries being more vulnerable due to more dependency on agriculture. Microorganisms can play important role as economic and farmer’s friendly strategy to combat abiotic stress in agriculture. A wide range of microorganisms associate with plants, and many of them confer beneficial effects to their hosts through different mechanisms like production of growth promoting substances, nutrient acquisition, protection against plant pathogens etc. In the last few decades, role of microorganisms in imparting tolerance to plants against different abiotic stress has been reported in many crop plants. Under stresses conditions, plant-microbe interactions become more common towards coping with the stress. Selection and application of efficient abiotic stress tolerant microorganisms can be a fruitful strategy to alleviate negative effects of abiotic stresses in plants.

Abstract

In its natural environment, a plant faces various types of stressors. In fact, stress in moderation is a welcome event in plants. Only when it is in excess, would it compromise the productivity of plants. Beyond a threshold, stress (biotic and abiotic) has a detrimental effect on plant growth causing extensive yield losses in crop plants worldwide. Plants being sessile, have evolved a complex set of mechanisms to perceive the changes in the environment. Plants respond to minimize the potential damage due to stress while simultaneously preserving resources vital for their growth and development. The chapter presents an overview of various types of biotic and abiotic factors that act as plant stressors and the mechanisms by which plants respond to these stresses. The chapter concludes with a perspective on how the plant’s innate stress response machinery can be exploited for achieving higher tolerance to stress in crop plants.

Abstract

Microbes are endowed with a high and exploitable potential of being useful associates with their surrounding environment and host in case of symbiotic relationship. Most of the microbes live alone but many of them require association of other living system for its survival. Hence, the beneficial role of microbes is always correlated with growth promotion and survivability of other associated living system. Now it is established that microbes play an important and key role in plant growth and development, even its survivability in case of symbiotic mycorrhizal association with orchids. They are nothing but potential tool protecting plants from different adverse conditions like diseased state, environmental stress like cold temperature, drought, metal contamination, salt and acidic or alkaline stress.

Abstract

Variously defined endophytes are highly diverse in plants in natural ecosystems, and most of them are symbiotic with of them are Asymptomatic presence of endophytic fungi in internal tissues on healthy host plants are able to play vital roles in physiology and biochemical processes. As a result of this interaction endophyte produces chemical substances having various applications. This chapter provides a brief review of certain grass and non-grass endophytes capable to extend beneficial impacts on host plants to sustain the unfavourable conditions of abiotic stresses. However, biotic stresses are also a matter of great concern, where endophytes can play important roles in combating the unfavourable situation. Endophytic fungi used in bio-control and other agriculture related sectors are also  highlighted in this review. Endophytic fungi producing volatile organic compounds reported from all over the world and their various applications find place in this article which has opened new frontiers of bioprospecting of endophytic fungi.

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.

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

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

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

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

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

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.