Browsing by Author "Devi, Loitongbam Lorinda"

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Brassinosteroids in plant growth and development
(Elsevier B.V., 2023) Yadav, Ritesh Kumar; Devi, Loitongbam Lorinda; Singh, Amar Pal
Brassinosteroids (BRs) are crucial for modulating several plant-related growth activities in the plant. The essential roles of BRs in modulating growth have been well characterized. Recently, BRs emerged as key players, which are accountable for governing stress-mediated responses like high temperature and nutrient deficiency. The genetic components of BRs signaling starting with membrane-confined receptors to the nuclear transcriptional effectors have been characterized. Here, we summarize the advances in the BRs signaling pathway and its spatiotemporal regulation in context with plant growth and development. Further, we highlight the essential role of BRs in regulating the root-and-shoot development, including the effect of BRs on stomata development and physiology as well as in root system architecture modulation. This summarized information will shed light on the current understanding of the BRs regulatory network and its multiple levels of cross talk with the other growth-related hormones in determining the plant performance under stress conditions.
Differential response of rice genotypes to nitrogen availability is associated with the altered nitrogen metabolism and ionomic balance
(Elsevier B.V., 2022) Kumari, Priyanka; Devi, Loitongbam Lorinda; Kumar, Amresh; Pandey, Ashutosh; Sinha, Subodh Kumar; Singh, Amar Pal
Nitrogen (N) uptake and its assimilation are crucial steps for plant growth and productivity. Plant's N balance largely depends on nitrate (NO3-) and ammonium (NH4+) forms present in the rhizosphere. Due to the fluctuating and heterogeneous availability of these N forms in the soils, plants encounter low to N deficiency. In contrast to low nitrogen, high N in the form of ammonium (NH4+) severely hampers plant development and causes NH4+ toxicity. In this study, we assessed eleven rice genotypes under sufficient (SN) and low N (LN) conditions. From the analysis, we identified a rice genotype, PB1, which is hypersensitive to SN and showed reduced root and shoot growth. In contrast to the SN condition, PB1 showed improved growth performance under the LN condition. Our data show that compromised growth of PB1 under SN condition is associated with increased activity of N responsive genes such as OsAMT1.1, OsAMT2.3, OsAMT3.1 and OsAMT3.2, OsNRT1.1A and OsNRT1.1B. Strikingly, LN treatment improved the root and shoot biomass with a concomitant increase in levels of NO3- and NH4+ transporter genes along with an increase in shoot: root NO3- ratio. Additionally, we show that increased levels of N in PB1 under SN condition are associated with the enhanced activity of the GS-GOGAT pathway. Further, our ionomic analysis highlighted the role of N-defined Fe accumulation which is partially associated with the N toxicity. Taken together, our study led to identifying a rice genotype (Oryza sativa L.) which is associated with enhanced N levels and assimilation and could be used for raising N use efficient rice varieties using breeding approaches.
The interplay of auxin and brassinosteroid signaling tunes root growth under low and different nitrogen forms
(Oxford University Press, 2022) Devi, Loitongbam Lorinda; Pandey, Anshika; Gupta, Shreya; Singh, Amar Pal
The coordinated signaling activity of auxin and brassinosteroids (BRs) is critical for optimal plant growth and development. Nutrient-derived signals regulate root growth by modulating the levels and spatial distribution of growth hormones to optimize nutrient uptake and assimilation. However, the effect of the interaction of these two hormones and their signaling on root plasticity during low and differential availability of nitrogen (N) forms (NH4+/NO3-) remains elusive. We demonstrate that root elongation under low nitrogen (LN) is an outcome of the interdependent activity of auxin and BR signaling pathways in Arabidopsis (Arabidopsis thaliana). LN promotes root elongation by increasing BR-induced auxin transport activity in the roots. Increased nuclear auxin signaling and its transport efficiency have a distinct impact on root elongation under LN conditions. High auxin levels reversibly inhibit BR signaling via BRI1 KINASE INHIBITOR1 (BKI1). Using the tissue-specific approach, we show that BR signaling from root vasculature (stele) tissues is sufficient to promote cell elongation and, hence, root growth under LN condition. Further, we show that N form-defined root growth attenuation or enhancement depends on the fine balance of BR and auxin signaling activity. NH4+ as a sole N source represses BR signaling and response, which in turn inhibits auxin response and transport, whereas NO3- promotes root elongation in a BR signaling–dependent manner. In this study, we demonstrate the interplay of auxin and BR-derived signals, which are critical for root growth in a heterogeneous N environment and appear essential for root N foraging response and adaptation.
Jasmonate signaling modulates root growth by suppressing iron accumulation during ammonium stress
(Oxford University Press, 2024) Pandey, Anshika; Devi, Loitongbam Lorinda; Gupta, Shreya; Prasad, Priti; Agrwal, Kanupriya; Asif, Mehar Hasan; Pandey, Ajay Kumar; Bandyopadhyay, Kaustav; Singh, Amar Pal
Plants adapt to changing environmental conditions by adjusting their growth physiology. Nitrate (NO3-) and ammonium (NH4+) are the major inorganic nitrogen forms for plant uptake. However, high NH4+ inhibits plant growth, and roots undergo striking changes, such as inhibition of cell expansion and division, leading to reduced root elongation. In this work, we show that high NH4+ modulates nitrogen metabolism and root developmental physiology by inhibiting iron (Fe)-dependent Jasmonate (JA) signaling and response in Arabidopsis (Arabidopsis thaliana). Transcriptomic data suggested that NH4+ availability regulates Fe and JA-responsive genes. High NH4+ levels led to enhanced root Fe accumulation, which impaired nitrogen balance and growth by suppressing JA biosynthesis and signaling response. Integrating pharmacological, physiological, and genetic experiments revealed the involvement of NH4+ and Fe-derived responses in regulating root growth and nitrogen metabolism through modulation of the JA pathway during NH4+ stress. The JA signaling transcription factor MYC2 directly bound the promoter of the NITRATE TRANSPORTER 1.1 (NRT1.1) and repressed it to optimize the NH4+/Fe-JA balance for plant adaptation during NH4+ stress. Our findings illustrate the intricate balance between nutrient and hormone-derived signaling pathways that appear essential for optimizing plant growth by adjusting physiological and metabolic responses during NH4+/Fe stress.
Nitric oxide: Interaction with auxins, brassinosteroids, and abscisic acid
(John Wiley & Sons, 2022) Gupta, Shreya; Devi, Loitongbam Lorinda; Singh, Amar Pal
Studies have identified the central role of nitric oxide in stress mitigation through the modulation of physiological and biochemical pathways including germination, photosynthesis regulation, and programmed cell death. Nitric Oxide in Plants: A Molecule with Dual Roles provides a detailed account of the physio-biochemical, molecular, and omic basis of NO-mediated responses in crop plants under different stresses. Summarizing recent work from leading researchers in the field, this up-to-date volume presents the current understanding of the modulation of the endogenous nitric oxide concentration following exogenous treatments and nitric oxide scavengers or inhibitors. The contributors discuss topics such as NO-mediated regulation of growth, photosynthesis, and tolerance mechanisms, the reductive and oxidative pathways of NO synthesis, molecular interventions for enhancing NO synthesis, the role of nitrogen in production of NO, beneficial microbes in NO production under normal and changing environmental conditions, and more.
Plant growth coordination during stress conditions: Role of phytohormones
(Elsevier B.V., 2024) Gupta, Shreya; Devi, Loitongbam Lorinda; Singh, Amar Pal
Plants encounter multiple stresses which are associated with compromised plant growth and yield across the globe. Several studies have been done in the past few years to understand plant acclimatization under numerous stresses like nutrient deficiency, drought, salinity, temperature, and pathogen attack. The shoot and root system architecture in plants seems a promising approach as it is highly sensitive to edaphic and internal signals and plants adapt by modulating them to these stresses. Intrinsic factors such as growth hormones are the key components of the plant whose levels and signaling determine the extent of plant growth and performance. The major phytohormones that are involved in monitoring plant development for optimized plant growth during environmental stresses are auxin, brassinosteroids, cytokinin, abscisic acid, jasmonic acid, gibberellins, and ethylene. In recent years, detailed genetic and biochemical analysis of the signaling and biosynthesis genes and transcription factors of these hormones have been studied from the model plant Arabidopsis to different crops. Genetic studies have shown that these hormones regulate several biological processes of root and shoot growth including cell elongation, division and differentiation, root hair and lateral root formation, and floral and leaf morphology in response to altered environmental conditions. In this chapter, the current understanding of both above- and below-ground plant organs and their developmental plasticity during stress conditions along with the interplay of growth hormones has been summarized and discussed.
Review: Emerging roles of brassinosteroid in nutrient foraging
(Elsevier B.V., 2020) Pandey, Anshika; Devi, Loitongbam Lorinda; Singh, Amar Pal
Brassinosteroids (BRs) are well-characterized growth hormones that are critical for plant growth, development, and productivity. Genetic and molecular studies have revealed the key components of BR biosynthesis and signaling pathways. The membrane-localized BR signaling receptor, BRASSINOSTEROID INSENSITIVE1 (BRI1) binds directly to its ligand and initiates series of signaling events that led to the activation of BR transcriptional regulators, BRASSINAZOLE RESISTANT1 (BZR1) and BRI1-ETHYL METHANESULFONATE-SUPPRESSOR1 (BES1/BZR2) to regulate the cellular processes. Insights from Arabidopsis research revealed tissue and cell typespecific roles of BR in controlling cell elongation and maintenance of stem cell niche in roots. More recently, BRs have gained much attention in regulating the root growth during nutrient deficiency such as nitrogen, phosphorus, and boron. Differential distribution of nutrients in the rhizosphere alters BR hormone levels and signaling to reprogram spatial distribution of root system architecture (RSA) such as a change in primary root growth, lateral root numbers, length, and angle, root hair formation and elongation. These morpho-physiological changes in RSA are also known as an adaptive root trait or foraging response of the plant. In this review, we highlight the role of BRs in regulating RSA to increase root foraging response during fluctuating nutrient availability.