The frequent occurrence of chromosomal abnormalities in humans is one of the main factors responsible for the birth of children with disabilities. More than 7.6 million infants per year are diagnosed with severe genetic abnormalities. An increase in genetic abnormalities among children may be attributed to women suffering from hormonal disorders. Genetic malformations can either be hereditary or spontaneous due to the exposure of germinal cells to toxins and mutagens or even oxidative stress. Most genetic disorders lack proper treatment. However, proper counseling, therapy, and medication can minimize its impact. Early diagnosis of abnormalities in the fetus will benefit the parents in options assessment. Fetal chromosomal analysis is the best option for an appropriate genetic disorder diagnosis. The latest and emerging technologies involved in detecting chromosomal abnormalities at the prenatal stage are discussed in this review. Significant developments in prenatal diagnostics and the best globally available economical options were also discussed.

This chapter provides an in depth study on the structure, composition, and organization of viral genomes, their classification into double stranded and single stranded DNA viruses, positive and negative stranded RNA viruses with and their genome diversity. Segmentation and re-assortment of viral genomes have been discussed along with the multipartite virus genomes. Genome details of 13 different viruses have been provided as type studies for better understanding of these topics. Concepts of viral genome evolution have also been discussed.

Genome databases are the locations, which permits storing, sharing, retrieving and comparison of the information related to the genomes of various individuals and organisms. Traditionally the databases were confined to the updated information of certain vital model organisms. Rapid development of technology and high speed internet facilities have created an explosion of databases resulting in the development of specific databases of almost all model organisms and a group of organisms with a common specificity. In the present chapter, details of the databases related to the genomes of viruses, archaea, bacteria, cell organelle, invertebrates, vertebrates, plants, and human beings are provided in a table format which provides an instant information, about different databases and their URLs.

This chapter reports the results of a study on Plectranthus species response to salinity stress caused by the saline irrigation water. The Plectranthus species are perennial, aromatic with sheath like stems and belongs to Lamieaceae family commonly found in tropical-to-subtropical climatic conditions. The chapter also reports the role of salinity stress on the growth and biomass production of different Plectranthus species as well as on their salinity stress adaptations mechanisms. Soil salinization influenced the potassium levels to considerable extent, reducing its presence in the soil. It might be due to sodium ions blocking the potassium preventing it from reaching the plant. Water uptake efficiency increased with increasing salinity indicating the adaptability of Plectranthus species to acclimatize at higher salinity stress levels. As anticipated, Plectranthus species have shown negative effect on its growth and biomass with increasing salinity stress.

Insect attack has become a serious agricultural problem responsible for reductions in crop productivity. Each year, an estimated 25% of the food crop is destroyed by insects. Plants confront pests by producing secondary metabolites such as terpenes, phenolics, nitrogen- and sulfur-containing compounds that either kill or retard its development. The development of insect-resistant crops is a major success in agriculture to reduce the use of pesticides, improve quality and yield, and decreases production costs. Plant genetic engineering technology offers the opportunity to develop insect-resistant crops by the insertion and expression of genes showing resistance to insect pests. Such insect-resistant crop varieties can be generated for economic importance by the use of either delta endotoxin coding sequences obtained from Bacillus thuringiensis bacterium or genes encoding lectins or enzyme inhibitors derived from plant species. It is now possible to decrease environmental pollution and increase crop productivity by cultivating crop varieties resistant to insect damage. This review focuses mainly on the development of insect-resistant crop varieties, techniques involved in their generation, and various other mechanisms responsible for the development of resistance against insects in plants.

Crop plants are regularly exposed to an array of abiotic and biotic stresses, among them drought stress is a major environmental factor that shows adverse effects on plant growth and productivity. Because of this these factors are considered as hazardous for crop production. Drought stress elicits a plethora of responses in plants resulting in strict amendments in physiological, biochemical, and molecular processes. Photosynthesis is the most fundamental physiological process affected by drought due to a reduction in the CO2 assimilation rate and disruption of primary photosynthetic reactions and pigments. Drought also expedites the generation of reactive oxygen species (ROS), triggering a cascade of antioxidative defense mechanisms, and affects many other metabolic processes as well as affecting gene expression. Details of the drought stress-induced changes, particularly in crop plants, are discussed in this review, with the major points: 1) leaf water potentials and water use efficiency in plants under drought stress; 2) increased production of ROS under drought leading to oxidative stress in plants and the role of ROS as signaling molecules; 3) molecular responses that lead to the enhanced expression of stress-inducible genes; 4) the decrease in photosynthesis leading to the decreased amount of assimilates, growth, and yield; 5) the antioxidant defense mechanisms comprising of enzymatic and non-enzymatic antioxidants and the other protective mechanisms; 6) progress made in identifying the drought stress tolerance mechanisms; 7) the production of transgenic crop plants with enhanced tolerance to drought stress.

The antioxidant defense system in the seeds of 18 different soybean varieties was evaluated by studying the concentrations of total antioxidants, ascorbate, glutathione, -tocopherol, total phenolics, flavonoids and tannins. The activities of enzymatic antioxidants superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.8.1.7) were also investigated in soybean seeds along with the concentrations of H2O2 and the lipid peroxidation (LP) rates were determined. Observations made in this study suggest that soybean seeds possess strong antioxidative defense system necessary for successfully ameliorating the toxicity of reactive oxygen species, and the varieties ADB-22, NRC-37 and LSB-1 have better antioxidative defense properties than other varieties, which will also enhance their nutritive values.Practical ApplicationsSoybean (Glycine maxL.) is an important legume crop, cultivated for its protein, edible oil and antioxidants. The rich nutraceutical constituents of soybean that have been isolated in earlier investigations are attributed to their protective properties against cancers and cardiovascular diseases. This paper presents the findings of a comprehensive investigation of total antioxidant content, lipid peroxidation rates and secondary metabolites in the seeds of 18 different soybean varieties grown in India, which can be used for the identification of superior varieties with respect to its antioxidant properties for their consumption.

Compounds extracted from plants with biological activity are the subject of interest for their role in the pharmaceutical and nutraceutical industries. Extraction of these compounds has been traditionally done using conventional methods using organic solvents and applying stringent conditions such as high temperatures resulting in the decrease of yield and purity. Developing alternative ecofriendly extraction techniques with better selectivity and efficiency are highly desired. In the past decade supercritical fluid extraction (SFE) technique has gained lot of attention in isolation of bioactive compounds from plants. The present review focus on the principles of supercritical fluid extraction technique and recent developments in the extraction of functional ingredients from plants. Fundamental concepts emphasising the procedures needed for the supercritical extraction of bioactive compounds from plants have been discussed along with its applications, advantages and disadvantages. Based on the extraction capabilities and many advantages of SFE, this technology is likely to be a highly beneficial and useful for extraction of compounds from plant products. Keywords: Bio-active compounds, conventional techniques, functional ingredients, supercritical fluid extraction, supercritical fluids.

Soil Salinity is being recognized as a major threat to the agriculture and food production in the arid and semi-arid soils. Accumulation of sodium, magnesium and calcium salts enhances the alkalinity of the soils making the crop production difficult. Plant system has developed certain adaptation strategies for tolerating the toxicity of the salts in the soil. The present review focuses on the probable sources of soil salinity, induction of toxicity mechanisms of salinity stress tolerance in crop plants along with the strategies needed to be adapted to make agriculture a sustainable one.

Ascorbate peroxidase (APX) is one of the major antioxidant enzymes involved in the detoxification of hydrogen peroxide. APX is found in chloroplast, cytosol and microsomes. The structural model for the APX izozymes has not been solved. In the present study, we describe the structural model for the chloroplast APX of Ipomea nil (morning glory) using homology model, which provides an insight for better understanding of APX molecular function in providing oxidative stress tolerance in plants.

Superoxide dismutase (SOD, EC 1.15.1.1) is an important metal-containing antioxidant enzyme that provides the first line of defense against toxic superoxide radicals by catalyzing their dismutation to oxygen and hydrogen peroxide. SOD is classified into four metalloprotein isoforms, namely, Cu/Zn SOD, Mn SOD, Ni SOD and Fe SOD. The structural models of soybean SOD isoforms have not yet been solved. In this study, we describe structural models for soybean Cu/Zn SOD, Mn SOD and Fe SOD and provide insights into the molecular function of this metal-binding enzyme in improving tolerance to oxidative stress in plants.

Salinity stress-induced morphological, physiological and biochemical responses of four soybean cultivars (MAU-61, LSB-1, NRC-37 and MACS-57) were studied in 30 days old plants by treating them with 100 mM, 200 mM and 300 mM concentrations of NaCl respectively. The effect of salinity on plant growth was studied by measuring the growth of the plant, branch length, leaf area. The water relations of soybean cultivars under salinity were estimated by studying the relative water contents and water uptake capacity. The response of the soybean plants to salinity stress was analysed by estimating the levels of carbohydrates, total free amino acids, proline, glycine betaine along with the enzymatic activities of superoxide dismutase and sucrose phosphate synthase. Carbohydrates and SPS activity were decreased in the soybean plants under salinity stress whereas the contents of proline, glycine betaine and total free amino acids were increased along with superoxide dismutase activity. Native polyacrylamide gel electrophoresis showed the accumulation of two SOD isoenzymes Mn-SOD and Cu/Zn SOD under salinity stress. Differential expression of these enzymes showed that the expression of these enzymes under salinity stress was high in roots. This study reveals that the varieties NRC-37 and MACS-57 showed a better performance under salinity stress, when compared to that of MAU-61 and LSB-1 which was very well correlated with their biomass contents.