Anjali Jaiwal

Bio: Anjali Jaiwal is an academic researcher from University of Delhi. The author has contributed to research in topics: RNA interference & Helicoverpa armigera. The author has an hindex of 3, co-authored 3 publications receiving 78 citations.

Advances in genetic improvement of Camelina sativa for biofuel and industrial bio-products

Abstract: Ever-increasing global energy demand, diminishing fossil fuel reserves and environmental concerns have forced to look for renewable and sustainable alternative energy sources preferentially from non-food crops. Camelina being a short-duration, low-cost, non-food oilseed crop with high content of oil (45%) rich in unsaturated fatty acids and capable of growing in marginal lands has emerged as a potential alternative for biofuel (with low carbon emission) and industrial bio-products. However, the fatty acid profile needs to be refined to make it more efficient for biodiesel and bio-products. Attempts to improve crop yield, oil content and composition through conventional and mutation breeding have been limited due to inadequate genetic diversity and availability of mutants. Simple and easy transformation and recent upsurge in ‘omics’ data (trancriptomics and genomics) has resulted in better understanding of lipid biosynthesis and its regulation, and thus has made it possible to produce unusual lipids with modified fatty acids for new functionalities. However, further improvement is still awaited for carbon assimilation efficiency, resistance to various abiotic and biotic stresses, seed yield, oil content and composition. This review extensively analyses the recent advances and challenges in using molecular markers, genomics, transcriptomics, miRNAs and transgenesis for improvement in biotic and abiotic stresses, carbon assimilation capabilities, seed yield, oil content and composition in camelina for biodiesel fuel properties, nutrition and high value-added industrial products like bioplastics, wax esters and terpenoids.

Coenzyme Q10 production in plants: current status and future prospects

Abstract: Coenzyme Q10 (CoQ10) or Ubiquinone10 (UQ10), an isoprenylated benzoquinone, is well-known for its role as an electron carrier in aerobic respiration It is a sole representative of lipid soluble antioxidant that is synthesized in our body In recent years, it has been found to be associated with a range of patho-physiological conditions and its oral administration has also reported to be of therapeutic value in a wide spectrum of chronic diseases Additionally, as an antioxidant, it has been widely used as an ingredient in dietary supplements, neutraceuticals, and functional foods as well as in anti-aging creams Since its limited dietary uptake and decrease in its endogenous synthesis in the body with age and under various diseases states warrants its adequate supply from an external source To meet its growing demand for pharmaceutical, cosmetic and food industries, there is a great interest in the commercial production of CoQ10 Various synthetic and fermentation of microbial natural producers and their mutated strains have been developed for its commercial production Although, microbial production is the major industrial source of CoQ10 but due to low yield and high production cost, other cost-effective and alternative sources need to be explored Plants, being photosynthetic, producing high biomass and the engineering of pathways for producing CoQ10 directly in food crops will eliminate the additional step for purification and thus could be used as an ideal and cost-effective alternative to chemical synthesis and microbial production of CoQ10 A better understanding of CoQ10 biosynthetic enzymes and their regulation in model systems like E coli and yeast has led to the use of metabolic engineering to enhance CoQ10 production not only in microbes but also in plants The plant-based CoQ10 production has emerged as a cost-effective and environment-friendly approach capable of supplying CoQ10 in ample amounts The current strategies, progress and constraints of CoQ10 production in plants are discussed in this review

RNA silencing of hormonal biosynthetic genes impairs larval growth and development in cotton bollworm, Helicoverpa armigera

Abstract: The cotton bollworm, Helicoverpa armigera, is a highly polyphagous pest, causing enormous losses to various economically important crops. The identification and in vitro functional validation of target genes of a pest is a prerequisite to combat pest via host-mediated RNA interference (RNAi). In the present study, six hormonal biosynthesis genes of H. armigera were chosen and evaluated by feeding insect larvae with dsRNAs corresponding to each target gene, viz., juvenile hormone acid methyltransferase (HaJHAMT), prothoracicotropic hormone (HaPTTH), pheromone biosynthesis-activating peptide (HaPBAP), molt regulating transcription factor (HaHR3), activated protein 4 (HaAP-4) and eclosion hormone precursor (HaEHP). The loss of function phenotypes for these hormonal genes were observed by releasing second instar larvae on to artificial diet containing target gene-specific dsRNAs. Ingestion of dsRNAs resulted in mortality ranging from 60% to 90%, reduced larval weight, phenotypic deformities and delayed pupation. The quantitative real-time PCR (qRT-PCR) analysis showed that the target gene transcript levels were decreased drastically (31% to 77%) as compared to control or unrelated control (GFP-dsRNA), and correlated well with the mortality and developmental defects of larvae. Also, a comparison of the silencing efficacy of un-diced long HaPTTH-dsRNA with RNase III diced HaPTTH-dsRNA (siRNAs) revealed that long dsRNAs were more efficient in silencing the target gene. These results indicated that the hormonal biosynthesis genes have varied sensitivity towards RNAi and could be the vital targets for insect resistance in crop plants like cotton which are infested by H. armigera.

Genetic Diversity and Population Structure of a Camelina sativa Spring Panel.

Abstract: There is a need to explore renewable alternatives (e.g., biofuels) that can produce energy sources to help reduce the reliance on fossil oils. In addition, the consumption of fossil oils adversely affects the environment and human health via the generation of waste water, greenhouse gases, and waste solids. Camelina sativa, originated from southeastern Europe and southwestern Asia, is being re-embraced as an industrial oilseed crop due to its high seed oil content (36-47%) and high unsaturated fatty acid composition (>90%), which are suitable for jet fuel, biodiesel, high-value lubricants and animal feed. C. sativa's agronomic advantages include short time to maturation, low water and nutrient requirements, adaptability to adverse environmental conditions and resistance to common pests and pathogens. These characteristics make it an ideal crop for sustainable agricultural systems and regions of marginal land. However, the lack of genetic and genomic resources has slowed the enhancement of this emerging oilseed crop and exploration of its full agronomic and breeding potential. Here, a core of 213 spring C. sativa accessions was collected and genotyped. The genotypic data was used to characterize genetic diversity and population structure to infer how natural selection and plant breeding may have affected the formation and differentiation within the C. sativa natural populations, and how the genetic diversity of this species can be used in future breeding efforts. A total of 6,192 high-quality single nucleotide polymorphisms (SNPs) were identified using genotyping-by-sequencing (GBS) technology. The average polymorphism information content (PIC) value of 0.29 indicate moderate genetic diversity for the C. sativa spring panel evaluated in this report. Population structure and principal coordinates analyses (PCoA) based on SNPs revealed two distinct subpopulations. Sub-population 1 (POP1) contains accessions that mainly originated from Germany while the majority of POP2 accessions (>75%) were collected from Eastern Europe. Analysis of molecular variance (AMOVA) identified 4% variance among and 96% variance within subpopulations, indicating a high gene exchange (or low genetic differentiation) between the two subpopulations. These findings provide important information for future allele/gene identification using genome-wide association studies (GWAS) and marker-assisted selection (MAS) to enhance genetic gain in C. sativa breeding programs.

Oxidative Stress and Antioxidant Metabolism under Adverse Environmental Conditions: a Review

Abstract: Reactive oxygen species (ROS) originate as a natural byproduct in standard metabolism of oxygen activities. The principal sites of ROS generation in the cell are apoplast, mitochondria, chloroplasts, and peroxisomes. These ROS can induce cellular injuries by proteins oxidation, lipid peroxidation, and DNA damage, which finally may result in plant cellular death. Under regular circumstances, there is a steadiness between generation and elimination of ROS, but this balance is hampered by different biotic and abiotic stress factors such as exposure to heavy metals, high and low-light conditions, pathogens, insects and temperature extremes, resulting in a high generation of ROS which should be counteracted by the antioxidant machinery in cells. The antioxidant system of defense is composed by two groups: (i) Enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), general peroxidases (PRX) (e.g. guaiacol peroxidase GPX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR); (ii) Non-enzymatic antioxidants such as ascorbic acid (AA), reduced glutathione (GSH), α-tocopherol, carotenoids, plastoquinone/ubiquinone and flavonoids. These two groups of metabolites and enzymes work together with the main aim of ROS scavenging, but also in determining plant signaling, immune response, and plant growth and development. Finally, the molecular genetics of ROS genes and related metabolic pathways are briefly outlined, including gene isoforms, cellular localization, detection methods used and interactions amongst them. This information is crucial in better understanding and designing procedures for plants´stress tolerance; leading to a better management of agricultural plants under challenging and changing climatic conditions and food security.

Plastoquinone and Ubiquinone in Plants: Biosynthesis, Physiological Function and Metabolic Engineering.

Abstract: Plastoquinone (PQ) and ubiquinone (UQ) are two important prenylquinones, functioning as electron transporters in the electron transport chain of oxygenic photosynthesis and the aerobic respiratory chain, respectively, and play indispensable roles in plant growth and development through participating in the biosynthesis and metabolism of important chemical compounds, acting as antioxidants, being involved in plant response to stress, and regulating gene expression and cell signal transduction. UQ, particularly UQ10, has also been widely used in people’s life. It is effective in treating cardiovascular diseases, chronic gingivitis and periodontitis, and shows favorable impact on cancer treatment and human reproductive health. PQ and UQ are made up of an active benzoquinone ring attached to a polyisoprenoid side chain. Biosynthesis of PQ and UQ is very complicated with more than thirty five enzymes involved. Their synthetic pathways can be generally divided into two stages. The first stage leads to the biosynthesis of precursors of benzene quinone ring and prenyl side chain. The benzene quinone ring for UQ is synthesized from tyrosine or phenylalanine, whereas the ring for PQ is derived from tyrosine. The prenyl side chains of PQ and UQ are derived from glyceraldehyde 3-phosphate and pyruvate through the 2-C-methyl-D-erythritol 4-phosphate pathway and/or acetyl-CoA and acetoacetyl-CoA through the mevalonate pathway. The second stage includes the condensation of ring and side chain and subsequent modification. Homogentisate solanesyltransferase, 4-hydroxybenzoate polyprenyl diphosphate transferase and a series of benzene quinone ring modification enzymes are involved in this stage. PQ exists in plants, while UQ widely presents in plants, animals and microbes. Many enzymes and their encoding genes involved in PQ and UQ biosynthesis have been intensively studied recently. Metabolic engineering of UQ10 in plants, such as rice and tobacco, has also been tested. In this review, we summarize and discuss recent research progresses in the biosynthetic pathways of PQ and UQ and enzymes and their encoding genes involved in side chain elongation and in the second stage of PQ and UQ biosynthesis. Physiological functions of PQ and UQ played in plants as well as the practical application and metabolic engineering of PQ and UQ are also included.

Progress and challenges in improving the nutritional quality of rice (Oryza sativa L.)

Abstract: Rice is a staple food for more than 3 billion people in more than 100 countries of the world but ironically it is deficient in many bioavailable vitamins, minerals, essential amino- and fatty-acids and phytochemicals that prevent chronic diseases like type 2 diabetes, heart disease, cancers, and obesity. To enhance the nutritional and other quality aspects of rice, a better understanding of the regulation of the processes involved in the synthesis, uptake, transport, and metabolism of macro-(starch, seed storage protein and lipid) and micronutrients (vitamins, minerals and phytochemicals) is required. With the publication of high quality genomic sequence of rice, significant progress has been made in identification, isolation, and characterization of novel genes and their regulation for the nutritional and quality enhancement of rice. During the last decade, numerous efforts have been made to refine the nutritional and other quality traits either by using the traditional breeding with high through...

Coenzyme Q10 supplementation: Efficacy, safety, and formulation challenges.

Abstract: World population growth and aging are posing unprecedented challenges in sustaining the health of 9.1 billion people that will be occupying the planet by 2050. Although noncommunicable diseases such as cardiovascular and neurodegenerative diseases, cancer, and diabetes are among the top 10 global causes of death, they can be prevented by risk factor reduction, early detection, and adequate treatment. Since a healthy diet along with dietary supplementation could play an important role to reduce morbidity and cut off its associated health care costs, research in the food and nutrition area is required to find solutions to global challenges affecting health. As a result of the healthy living trend, dietary supplements category is growing fast, leading to an urgent need for dietitians, physicians, and policy makers to broaden the scientific evidence on the efficacy and safety of a wide range of active ingredients. Coenzyme Q10 (CoQ10), as the third most consumed dietary supplement, and as a potential candidate for the treatment of various noncommunicable diseases that are among the global top 10 causes of death, has gained interest over years. Scientific evidence regarding mainly CoQ10 efficacy and safety, as well as formulation challenges, is addressed in this review.