Sharda Choudhary

Gene Silencing in Horticultural Transgenic Crops

Abstract The chapter considers gene silencing in horticulture transgenic crops. Horticulture involves a variety of plants and crops including fruit, vegetables, spices, and ornamental plants. Gene silencing refers to the ability of a cell to prevent the expression of a certain gene. With the cleavage or translational repression of the messenger RNA (mRNA) molecules, the genes that form them are essentially inactive. Horticultural plants have evolved a variety of gene silencing pathways in which small RNAs (20–30 nucleotides) repress the expression of genes at the transcriptional or post-transcriptional level. Gene silencing using RNA interference technology, transcriptional gene silencing, and virus-induced gene silencing has been used in horticultural crops. The presence of double-strand RNAs inside the cell lead to the production of small interfering RNAs, short hairpin RNAs, and microRNAs. The production of these RNAs lead to the silencing of mRNA (actual protein coating RNA). This technique is a very effective experimental tool to silence specific genes for better stress tolerance, enhance insect/pest/pathogen resistance, and improve nutritional status. This technique and mechanism can be controlled by artificial means and applied for the improvement of cultivars of a variety of horticultural crops.

Genetic evidence for susceptibility and resistance against scrapie in Indian sheep

Scrapie is a fatal, neurodegenerative disease of sheep and goats (Prusiner 1982). The cause behind the disease is infection by prion proteins (Prusiner 1982). The progression of scrapie is known to be influenced by the amino acid polymorphism of the host prion protein (PRNP) gene (Belt et al. 1995). The present study was carried out on Indian sheep breeds i.e., Karnah, Mandya, Malpura and Garole to identify polymorphisms of the PRNP gene at codons (136, 154 and 171) responsible for the susceptibility and resistance of the scrapie disease in sheep. The known risky allele (ARQ) was found to be the most frequent (77.75%). The most resistant (ARR) and most susceptible (VRQ) alleles were found equally distributed with a frequency of 1.75%. Although, most of the alleles were known to confer susceptibility or partial susceptibility to scrapie, yet so far none of the Indian sheep breeds showed any clinical symptoms of the disease. The possible reason could be genotype–environment interaction, management practices and/or resistance of Indian sheep to scrapie via some other mechanism. Fatal neurodegenerative prion diseases are both genetic and infectious to humans and other mammals (Prusiner 1991). Scrapie is considered as a prototype of various forms of prion diseases that include bovine spongiform encephalopathy (BSE) in cattle and Creutzfeldt–Jakob disease in human (Prusiner 1991). It is characterized by the accumulation of an abnormal isoform of the PRNP in the central nervous system (Prusiner 1991). Scrapie is a rare, contagious, slowly progressive, endemic brain disease in

In-silico scrutiny of cumin (Cuminum cyminum L.) protein structure-GQ 33

Cumin (Cuminum cyminum L.) belongs to Apiaceae family, is an important seed spice and one of the earliest spices used by mankind for its aromatic and medicinal properties. Cumin seeds are very commonly used to give flavour and texture to the food. In addition, it also acts as preservative and provides nutritional and health benefits. The typical aroma of the cumin seeds is due to their volatile oil content, the principal constituent of which is cuminol (cumin aldehyde). Studies have been done on properties of the essential oil content of cumin and other aspects. Only few studies are available citing the nucleotides sequences present in cumin but no reports are available on in-silico studies of proteins structure supposed to be present in cumin. In the present study, a high quality 3D structure and function of cumin protein (GQ 33) have been predicted for the hypothetical amino acid sequence obtained from reported nucleotides of cumin. The physiochemical properties for GQ 33 cumin protein were identified using Protparam. The instability index 39.52, isoelectric point (pI) 9.97 and grand average hydropathicity (GRAVY) -0.245 determined from primary and secondary structural analysis illustrate the stability of GQ 33 protein. Stability of 3D structure of protein was confirmed using Ramachandran plot having 95.7% residues or empirically distributed data-points present in the structure lie in most favoured region. For the prediction of secondary structure of protein FASTA sequences were used and prediction was performed using PSIPRED, JPRED, Protein Predict and SOPMA. SAVES server was used for further validation of protein structure.