Bisma Malik

Signaling in Response to Cold Stress

World population is growing at a fast pace and is projected to reach 6.5 billion by 2050. At the same time, numbers of changes that are occurring in regular environmental parameters are posing threats to the agricultural productivity. Thus, feeding 6.5 mouths would indeed be a huge challenge. Besides the ever-growing human population and alterations in environmental scenarios, reduction in the area of land used for agriculture, declination of crop productivity, overexploitation of bioresources, mal-agricultural practices, and deleterious abiotic environmental stresses are leading to ecological imbalance. To reduce these losses scientists all over the world focus on novel strategies to enhance crop production in order to meet the increasing food demand and establish a balance among different ecological factors. The various abiotic stress conditions such as cold, temperature, drought and salinity cause noxious effects on plant growth and development ultimately affecting the crop productivity. Among various abiotic stresses, cold stress is one of the main environmental stresses that limits the crop productivity and geographical distribution of most valuable crop plants. However, plants show remarkable developmental plasticity to survive in a continually changing environment. Being sessile, plants have generated in the course of their development proficient strategies of tremendous response to elude, tolerate, or adapt to various types of environmental stress conditions including cold. The acclimatization to various abiotic stress factors is largely dependent upon the activation of cascades of molecular channels involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Understanding the pathway mechanisms by which plants recognize these stress signals and then transduce them to cellular machinery in order to stimulate adaptive responses is of crucial importance to crop biology. Here we summarize cold stress tolerance mechanism pathways in plants. The main significant points discussed in this chapter include (a) adverse effects of cold stress on plant physiochemical parameters, (b) sensing of cold temperature and involvement of various signal transduction pathways, (c) function of various compatible solutes or osmoprotectants, and (d) types and functions of different cold-responsive genes and transcription factors (TFs) involved in various cold stress tolerance mechanisms.

Recent Trends and Approaches in Phytoremediation

The current technique of remediation of heavy metal from contaminated soil is not cost-effective and eco-friendly. Besides, these heavy metals are recalcitrant and are not degraded like organic compounds, therefore effective clean-up requires their immobilization to reduce or remove toxicity. Phytoremediation in future will play an important role in attaining the goals towards sustainable development. The recent development in biotechnology has generated a large knowledge base and thus has opened many opportunities for research and development in the field of phytoremediation. In this chapter we summarize some recent approaches in phytoremediation and how genetic engineering plays an important role to improve the potential of phytoremediation.

Phytoremediation: An Eco-Friendly Green Technology for Pollution Prevention, Control and Remediation

Among the environmental concerns the accumulation of heavy metals is of prime importance. The factors that are generally responsible for deteriorating soil quality include geological and anthropogenic activities. Besides, due to constantly changing urbanization and industrialization patterns the quality of the soil has greatly been affected which ultimately poses a threat to the ecosystem, food safety and human health. Reclamation of these contaminated soils by engineering methods is expensive, time consuming and sometimes not eco-friendly. Researchers all over the world are focusing to exploit the potential of plants as phytoremediators, a technology which is cost-effective, sustainable and eco-friendly. Phytoremediation technology is emerging gradually and as one of the important components of green technology which aims to employ plants across various genera for restoring ecosystem health. Plants possess a natural ability to eliminate, detoxify or immobilize environmental contaminants in a growth matrix by means of various biological processes. The main significant points discussed in this chapter include the mechanisms of phytoremediation and factors affecting phytoremediation.

Plant Signaling: Response to Reactive Oxygen Species

It is noteworthy to mention how the last 20 years have modified the concept of signalling in plants, especially the molecular crosstalk associated with it. Plants have the ability to show remarkable developmental plasticity to sustain in a continually changing environment. In response to various environmental stresses such as drought, salinity, metal toxicity, temperature and pathogens, plants defend themselves by developing some special defence mechanisms. Plants recognise these environmental signals with the help of some membrane protein sensors and then transduce these signals to the nucleus which ultimately stimulates various transcription factors and genes to form the product that ultimately leads to plant adaptation and assists the plant to sustain and surpass the adverse conditions. Amongst the environmental factors which are involved in signalling is the reactive oxygen species (ROS) generated during cell metabolism. ROS are spontaneously produced in the cell enzymatically through the action of various soluble membrane-bound enzymes and nonenzymatically by autoxidation reactions. Some of these ROS (e.g. superoxide dismutase, hydrogen peroxide and nitric oxide) are physiologically useful and in fact necessary for life but can also be harmful if present in excess or in inappropriate amounts. Current research in this regard focuses more on the development of transgenic plants with enhanced tolerance to ROS by using genetic approaches and analytical techniques. In particular nitric oxide (NO), a reactive radical, may be involved in the defence mediated by the ROS such as defence gene activation, hypersensitive response cell death and phytoalexin biosynthesis. By using biotechnological approaches NO together with ROS activates a stronger response and tolerance to various stresses in plants.

Biomass Pellet Technology: A Green Approach for Sustainable Development

The supply of sustainable or green energy is the main challenge that mankind will face over the coming decades, especially because of the need to address climatic changes. Biomass being abundantly available in nature can make a substantial contribution to cater future energy demands in a sustainable way. Currently, it is the largest universal contributor of green energy and has significant potential to expand in the production of electricity, heat and fuels. However, handling as well as direct combustion of biomass is restrained due to peculiar properties of this kind of fuel. As raw biomass possesses low density (30–50 kg/m3) and high moisture content that limits its usage for energy purposes and it needs to be densified prior to its use. The compact and densified biomass possess a high magnitude of density as well as low moisture content which in turn helps to dwindle technical limitations associated with storage, handling and transportation. One immediate solution is the pelletisation of raw biomass that enhances its energy efficiency and enables the competition of biomass with other types of fuels. Besides, biomass pellet technology has gained a rapid momentum in many European countries. The future of the biomass pellet industry is greatly influenced by various environmental, economic, political as well as social aspects that create a multiplex relation among suppliers, producers and consumers. Therefore, the main aim of this chapter is to develop a comprehensive review of biomass processing that involves pellet production technology, energy efficiency of biomass pellet, current status, opportunities and challenges for the development of biomass pellet market.

Lignocellulosic Biomass: As Future Alternative for Bioethanol Production

Biofuels provide a potential and promising green alternative to avoid the global political instability and environmental crises that arise from dependence on petroleum. It has an important role to mitigate global warming and to conserve fossil fuels. Currently, starchy crops such as corn are utilized as a source of raw material for the production of bioethanol but it cannot meet global fuel requirements. Besides, due to their food value these conventional crops are not able to cater the demand of biofuel production. Therefore, lignocellulosic biomass seems to be an attractive alternative for inexorable supplies of biofuels, cutting down the credence on fossil fuel resources. Lignocellulosic biomass feedstock is abundant, recyclable, cheap, and is evenly distributed in nature. However, lignocellulosic bioethanol production is not commercialized at a large scale due to certain economic and technical barriers which make ethanol production exorbitant. Therefore, research should be focussed to develop commercially profitable processes (green technology) for bioethanol production. Moreover, current approach is focussed on enzyme-based conversion of lignocellulosic biomass to bioethanol. The assurance of highly dynamic conversion coupled to a “Green” technology is now universally appealing. Therefore, the main aim of this chapter is to critically analyze the current situation and future needs for technological developments in the area of producing liquid biofuels from lignocellulosic biomass. It primarily covers distinct lignocellulosic biomass conversion technologies, challenges, and future research targets.

Characterization of mercury-induced stress biomarkers in Fagopyrum tataricum plants

ABSTRACT The effect of mercury stress on antioxidant enzymes, lipid peroxidation, photosynthetic pigments, hydrogen peroxide content, osmolytes, and growth parameters in Tartary buckwheat were investigated. The effect of Hg-exposure was found to be time (15 and 30 days) and concentration (0, 25, 50, and 75 μM) dependent. Hg was readily absorbed by seedlings with higher content in roots and it resulted in reduction of root and shoot length. The root and shoot Hg uptakes were significantly and directly correlated with each other. However, the fresh mass and biomass increased up to 50 μM Hg-treatment at both time periods. A significant positive correlation was observed between biomass accumulation with relative water content. Hg levels were positively correlated with the production of hydrogen peroxide in leaves as evidenced by 3, 3-diaminobenzidine (DAB)-mediated tissue fingerprinting. The osmolyte levels in general were elevated except for proline and protein which showed a decline at 75 μM Hg-treatment at 30-days. Amongst the photosynthetic pigments, chlorophyll showed a decline while as carotenoid and anthocyanin levels were elevated. The activity of antioxidant enzymes such as ascorbate peroxidase (APX), guaiacol peroxidase (POD), glutathione reductase (GR), Glutathione-s-transferase (GST) and superoxide dismutase (SOD) were positively correlated with Hg-treatment except SOD, which declined at 75 μM Hg-treatment in 30-days old seedlings. Catalase (CAT) activity showed a positive correlation up to 50 μM Hg-treatment but at 75 μM Hg-stress it decreases at both 15 and 30 days.

Cellulases: Industrial Workhorse in Bioenergy Sector

There exists a diverse array of microorganisms in the environments which secretes cellulase enzyme. Cellulases are multienzyme proteins acting on cellulose to convert them into smaller sugar components such as glucose. These enzymes are widely used in many industrial applications such as processing cotton, recycling paper and additivities of feed. The challenges which the world faces currently are concerned with rising oil prices and global warming, and in this context, the cellulases have gained importance as the property of cellulases in cellulose degradation has played an important role in sustainable biofuel production. However, high cost of cellulases is one of the biggest hindrances for commercialization of cellulosic biofuel technology and for bringing out the cost-effective technology; major research is focused on enhancing enzyme efficiency and in reducing capital costs.

Biosynthesis of Nanoparticles and Their Application in Pharmaceutical Industry

Nanotechnology originates from the physical, chemical, biological, and engineering sciences where novel approaches are being unfolded to investigate and maneuver single atoms and molecules for multiple applications in different fields of scientific world. In this technology, nanoparticle, a minute object, functions as an entire unit in terms of its transport and attributes. The nanosystem that involves science and engineering technology is one of the most exigent and time-demanding areas of research in nanotechnology. In the recent years, due to the advancement in science and technology, researchers have attempted to synthesize nanoparticles within the size range of 100 nm, and this extensive research and concern on nanoparticles is widening due to their potential application in wide areas of science and technology. The development of technology and progress of mankind have always been connected with the advancements of material science and material processing technology. Currently the research and the progress in nanotechnology and the validation based on various specified size effects in nanomaterials reveal that most of the new findings and designs of the future will be based on qualities of nanomaterials. In this field of technology, nanoparticle has massive scope for pharmaceutical industries which include health-care products and much more such as burn dressings, antimicrobial applications, medical devices, and scaffolds. Several approaches have been employed for the synthesis of nanomaterials which includes chemical reduction, photochemical reactions, electrochemical techniques, and green chemistry route. Among different types of nanoparticles, the metallic nanoparticles such as silver, gold, zinc, iron, and metal oxide have shown considerable improvement in the field of biomedical utilization, not only because of their high surface area-to-volume ratio but also because they display several medicinal properties. It is in this perspective that the current review will focus on the biosynthesis of nanoparticles and their application in pharmaceutical industry and also try to overview the most recent developments in this field.

Molecular Genetics of Buckwheat and Its Role in Crop Improvement

Abstract The cultivation of several species of buckwheat has been performed in many parts of the world for a long time. Although the genus Fagopyrum has a significant amount of genetic diversity in its wild and cultivated forms, it faces some major challenges such as low and unstable yields, indeterminate growth habit, seed shattering, lodging, and the low shelf life of its flour. Major efforts are needed to make its cultivation more popular by improving its quantitative as well as qualitative traits. This is possible only by making improvements in crop genetics, agronomic practices, and postharvest systems. The molecular approaches offer tremendous possibilities for genetic diversity assessment, improving our understanding of complex characters as well as providing the basis for effective breeding strategies when coupled with more traditional methods. Molecular markers are considered to be among the most promising, reliable, and effective tools in understanding the crop genetics studies. Their use can range from population genetic and evolutionary studies to construction of genetic maps and tagging genes responsible for economically important characters, including loci associated with quantitative traits (quantitative trait loci-QTLs). Moreover, these approaches should be adopted in such a way that helps in maintaining their diversity and improving their performance as per the breeders’ and consumers’ needs. There has been a tremendous amount of diversity in the buckwheat genus in its wild and cultivated forms which therefore could provide raw material for its genetic improvement. Information on the distribution and diversity of wild progenitors of buckwheat is still scant. In this chapter, we will talk about the major developments in the buckwheat crop improvement program that have been made so far by adopting modern genetic and molecular approaches.