Department of Plant Sciences

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https://dspace.uohyd.ac.in/handle/1/111

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Browsing Department of Plant Sciences by Author "Aggarwal, Pooja Rani"
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    Diverse role of phytic acid in plants and approaches to develop low-phytate grains to enhance bioavailability of micronutrients
    ( 2021-01-01) Pramitha, J. Lydia ; Rana, Sumi ; Aggarwal, Pooja Rani ; Ravikesavan, Rajasekaran ; Joel, A. John ; Muthamilarasan, Mehanathan
    Natural or synthetic compounds that interfere with the bioavailability of nutrients are called antinutrients. Phytic acid (PA) is one of the major antinutrients present in the grains and acts as a chelator of micronutrients. The presence of six reactive phosphate groups in PA hinders the absorption of micronutrients in the gut of non-ruminants. Consumption of PA-rich diet leads to deficiency of minerals such as iron and zinc among human population. On the contrary, PA is a natural antioxidant, and PA-derived molecules function in various signal transduction pathways. Therefore, optimal concentration of PA needs to be maintained in plants to avoid adverse pleiotropic effects, as well as to ensure micronutrient bioavailability in the diets. Given this, the chapter enumerates the structure, biosynthesis, and accumulation of PA in food grains followed by their roles in growth, development, and stress responses. Further, the chapter elaborates on the antinutritional properties of PA and explains the conventional breeding and transgene-based approaches deployed to develop low-PA varieties. Studies have shown that conventional breeding methods could develop low-PA lines; however, the pleiotropic effects of these methods viz. reduced yield, embryo abnormalities, and poor seed quality hinder the use of breeding strategies. Overexpression of phytase in the endosperm and RNAi-mediated silencing of genes involved in myo-inositol biosynthesis overcome these constraints. Next-generation genome editing approaches, including CRISPR-Cas9 enable the manipulation of more than one gene involved in PA biosynthesis pathway through multiplex editing, and scope exists to deploy such tools in developing varieties with optimal PA levels.
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    Hormonal crosstalk in regulating salinity stress tolerance in graminaceous crops
    ( 2021-12-01) Choudhary, Pooja ; Pramitha, Lydia ; Rana, Sumi ; Verma, Shubham ; Aggarwal, Pooja Rani ; Muthamilarasan, Mehanathan
    Soil salinity is one of the major threats that pose challenges to global cereal productivity and food security. Cereals have evolved sophisticated mechanisms to circumvent stress at morpho-physiological, biochemical, and molecular levels. Salt stress cues are perceived by the roots, which trigger the underlying signaling pathways that involve phytohormones. Each phytohormone triggers a specific signaling pathway integrated in a complex manner to produce antagonistic, synergistic, and additive responses. Phytohormones induce salt-responsive signaling pathways to modulate various physiological and anatomical mechanisms, including cell wall repair, apoplastic pH regulation, ion homeostasis, root hair formation, chlorophyll content, and leaf morphology. Exogenous applications of phytohormones moderate the adverse effects of salinity and improve growth. Understanding the complex hormonal crosstalk in cereals under salt stress will advance the knowledge about cooperation or antagonistic mechanisms among hormones and their role in developing salt-tolerant cereals to enhance the productivity of saline agricultural land. In this context, the present review focuses on the mechanisms of hormonal crosstalk that mediate the salt stress response and adaptation in graminaceous crops.
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    Molecular and metabolomic interventions for identifying potential bioactive molecules to mitigate diseases and their impacts on crop plants
    ( 2021-04-01) Choudhary, Pooja ; Aggarwal, Pooja Rani ; Rana, Sumi ; Nagarathnam, Radhakrishnan ; Muthamilarasan, Mehanathan
    The multifaceted defense response of plants involves bioactive natural compounds that recognize, intervene, and neutralize the incoming pathogens. Plant secondary metabolites play roles at different stages of infection and disease progression. Studies have shown the synthesis of specific metabolites to confer resistance or tolerance depending on disease severity and other related factors. However, information on the presence, involvement, and regulation of several metabolites remains largely unavailable. The advent of next-gen omics approaches and the availability of high-throughput metabolomics platforms could expedite the studies in this direction. Given this, the present review details the role of secondary metabolites in plant defense, their modulation to achieve better immunity, and the tools and techniques available to study these metabolites. Further, the review also provides a roadmap for undertaking such studies in major crops to delineate the precise roles of novel metabolites and extrapolate the information for developing crops with better resistance against the broad-spectrum of pathogens.