Salah ud Din

In-Silico Determination of Insecticidal Potential of Vip3Aa-Cry1Ac Fusion Protein Against Lepidopteran Targets Using Molecular Docking.

Study and research of Bt (Bacillus thuringiensis) transgenic plants have opened new ways to combat insect pests. Over the decades, however, insect pests, especially the Lepidopteran, have developed tolerance against Bt delta-endotoxins. Such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. In this computational study, functional domains of Bacillus thuringiensis crystal delta-endotoxin (Cry1Ac) insecticidal protein and vegetative insecticidal protein (Vip3Aa) have been fused to develop a broad-range Vip3Aa-Cry1Ac fusion protein. Cry1Ac and Vip3Aa are non-homologous insecticidal proteins possessing receptors against different targets within the midgut of insects. The insecticidal proteins were fused to broaden the insecticidal activity. Molecular docking analysis of the fusion protein against aminopeptidase-N (APN) and cadherin receptors of five Lepidopteran insects (Agrotis ipsilon, Helicoverpa armigera, Pectinophora gossypiella, Spodoptera exigua, and Spodoptera litura) revealed that the Ser290, Ser293, Leu337, Thr340, and Arg437 residues of the fusion protein are involved in the interaction with insect receptors. The Helicoverpa armigera cadherin receptor, however, showed no interaction, which might be due to either loss or burial of interactive residues inside the fusion protein. These findings revealed that the Vip3Aa-Cry1Ac fusion protein has a strong affinity against Lepidopteran insect receptors and hence has a potential to be an efficient broad-range insecticidal protein.

An overview of phytochrome: An important light switch and photo-sensory antenna for regulation of vital functioning of plants

Abstract Plants are the primary source of nutrition and essential to maintain life on earth. They have evolved very delicate and advanced photo-sensory antennae to sense their outer environment and transduce the received information for their growth and development accordingly. This “light switch” phenomenon of plants has slowly being unraveled and various plant photoreceptors, their role in downstream molecular signaling, mutual interaction, response to circadian cycle and light signals have been discovered. The photosensory antennae in plants; phytochromes, cryptochromes and phototropins play a very crucial role in sensing the ambient light intensities. By direct interaction with the environment through these photosensory antennae, plants shift their homeostasis to regulate their growth and development. The phytochrome light receptors of plants are responsive to R/FR light and by inducing signaling pathways, trigger the physiological responses such as germination and flowering. The phytochromes also directly contribute to plant development by affecting its photosynthetic rate. To elucidate the role of phytochromes in plant metabolism, this review will focus on the importance of phytochromes, their mechanism of action and their application as an emerging field in plant biology.

Sucrose synthase genes: a way forward for cotton fiber improvement

Cotton is a premium source of natural fiber and is considered “white gold” in the textile industry. Fiber length, strength and fineness are the key considerations for the industry. Longer fibers are machine friendly because they are easily spinnable. Recent advancements in genetic engineering, including the development of DNA markers and quantitative trait loci (QTLs), together with genome sequencing and gene expression profiling, have provided new avenues for improving fiber production and quality. In plants, sucrose synthase (SUS) is the key enzyme that catalyzes the reversible cleavage of sucrose and uridine diphosphate (UDP) into fructose and UDP-glucose. Sucrose is the main mobile sugar in plants moving from source to sink. It regulates resource partitioning between active sinks, especially in cotton embryos and fibers, and therefore is directly involved in determining fiber yield and seed quality. SUS actively takes part in regulating the competition for nutrients among sink tissues through balancing osmotic potentials by providing hexoses and an efficient supply of UDP-glucose the substrate for cellulose synthase. Cotton transformation has been used to improve fiber characteristics by altering cell wall properties through the manipulation of expression of fiber genes. Overexpression of the SUS gene from natural or synthetic origins in cotton can be an excellent way to solve potential problems associated with poor fiber length and other fiber quality traits. Increased SUS activity can result in more hexoses, increasing the osmotic potential and thereby driving the water influx that creates high turgor pressure in fiber cells resulting in enhanced fiber elongation. Moreover, increased SUS gene transcript levels in vegetative tissues of the plant will elevate seedling biomass and seed number. Fiber length and seed number both contribute towards final yield and the SUS genes as key regulators of sink strength in cotton perform this dual function that is directly related to cotton productivity. Hence manipulation of the SUS gene family is considered a promising approach to improve cotton fiber yield and quality. This review focuses on the biochemical and physiological roles of the SUS genes and there value for cotton fiber improvement.

Genomics of Salinity Tolerance in Plants

Plants are frequently exposed to wide range of harsh environmental factors, such as drought, salinity, cold, heat, and insect attack. Being sessile in nature, plants have devel‐ oped different strategies to adapt and grow under rapidly changing environments. These strategies involve rearrangements at the molecular level starting from transcription, regu‐ lation of mRNA processing, translation, and protein modification or its turnover. Plants show stress-specific regulation of transcription that affects their transcriptome under stress conditions. The transcriptionally regulated genes have different roles under stress response. Generally, seedling and reproductive stages are more susceptible to stress. Thus, stress response studies during these growth stages reveal novel differentially regu‐ lated genes or proteins with important functions in plant stress adaptation. Exploiting the functional genomics and bioinformatics studies paved the way in understanding the rela‐ tionship between genotype and phenotype of an organism suffering from environmental stress. Future research programs can be focused on the development of transgenic plants with enhanced stress tolerance in field conditions based upon the outcome of genomic approaches and knowing the mystery of nucleotides sequences hidden in cells.

EFFECT OF OXIDATION ON ACID, SAPONIFICATION AND IODINE VALUES OF LINSEED OIL

Oil from locally grown linseed was extracted with petroleum ether. The freshly extracted oil was exposed to open air and an atmosphere of oxygen for different duration of time and changes in the characteristic values such as acid, saponification and iodine values were monitored. A noticeable decrease occurred in the saponification and iodine values, by increasing the time of exposure. Moreover the decrease in oxygen atmosphere was much pronounced compared to that in open air. The acid value even though, decreased slightly in oxygen atmosphere within a few hours was nearly unaffected in open air even when exposed for several days. The decrease in the various characteristic values were attributed to the oxidation of the oil molecules at the double bonds resulting in the formation of peroxide and ketol.