Publications of NIPGR Scientists
Permanent URI for this communityhttps://ndkr-library.nipgr.ac.in/handle/123456789/1
Browse
48 results
Search Results
Item Navigating heavy metal stress: emerging roles of TOR and SnRK signaling in plant tolerance(Frontiers Media S.A., 2026) Naaz, Sheeba; Laxmi, AshveryaThis review explores emerging insights about how plants regulate their responses to heavy metal stress through the coordinated actions of the Target of Rapamycin (TOR) and Sucrose Non-Fermenting-1-Related Kinase (SnRK) signaling pathways. Toxic heavy metals such as As, Pb, Cd and Hg cause severe metabolic and oxidative stress in plants, which reduces their growth and development and ultimately disrupts cellular homeostasis. In this review, we highlight the unique direction of research that focuses on TOR-SnRK interaction under heavy metal exposure, emphasizing their opposite yet interconnected roles in metabolic reprogramming, stress tolerance, and in growth regulation. Under heavy metal stress, SnRK kinases are activated, which triggers the expression of stress-responsive genes and activates autophagy, while downregulating TOR activity to conserve energy and divert resources toward defense, which maintains redox homeostasis, allows plants able to survive. TOR-SnRK pathways interacts with calcium, hormonal, and redox signaling networks, which further strengthen plant stress responses and regulate tolerance mechanisms. Understanding the TOR-SnRK pathway provides a deepened understanding of how plants regulate energy under toxic environmental conditions. In addition to these, targeting these pathways assists in designing crops and agricultural products that are more resilient to heavy metal toxicity, promoting sustainable agriculture in contaminated areas.Item Sweet shaping of root system architecture under water deficit(Oxford University Press, 2026) Singh, Dhriti; Awasthi, Prakhar; Sharma, Aishwarye; Samtani, Harsha; Shukla, Brihaspati Narayana; Laxmi, AshveryaRoot growth direction under water-deficit conditions is critical for plant survival. Increasing agar concentration in the growth medium simulates stress conditions, limiting water availability. Our study highlights the role of glucose (Glc) in orchestrating the root growth deviation in Arabidopsis under stress conditions. We demonstrate that Glc-TOR signaling plays a central role in modulating root growth direction under stress conditions. Conversely, cytokinin (CK) signaling reduces root deviation during water deficit. We further show that Glc downregulates CK signaling under water-deficit conditions, while CK negatively influences Glc–TOR activity. The interplay between Glc-TOR and CK signaling pathways fine-tunes root orientation by modulating auxin transport and signaling. Collectively, our findings show that in Arabidopsis, Glc-induced changes in root architecture are mediated through its antagonistic interaction with CK signaling, contributing to enhanced root plasticity and improved adaptation to water-limited conditions.Item The confluence of TOR signaling and plant growth regulators in development and stress responses(Oxford University Press, 2026) Saksena, Harshita B; Kumar, Mukesh; Samtani, Harsha; Sharma, Aishwarye; Rawat, Sanjay Singh; Awasthi, Prakhar; Botta, Halidev Krishna; Sandhya, Shital; Pande, Anjali; Naaz, Sheeba; Kushwah, Sunita; Shukla, Brihaspati N; Laxmi, AshveryaThe Target of Rapamycin (TOR) is an evolutionarily conserved protein kinase that serves as a crucial signaling hub, seamlessly integrating a wide range of internal and external signals to meticulously regulate cellular and organismal physiology. TOR is crucial in regulating the different phases of lifecycle in plants including embryogenesis, seed germination, meristem activation, root and leaf development, flowering and senescence. Beyond its central role in growth and development, emerging research has revealed its significant involvement in the response to environmental stresses. Even though plant growth regulators such as auxin, cytokinin (CK), brassinosteroid (BR), gibberellin (GA), abscisic acid (ABA), ethylene (ET), salicylic acid (SA), jasmonic acid (JA) and nitric oxide (NO) function as pivotal signaling molecules in modulating plant development and stress responses, how they coordinate with the energy status still remains obscure. Here we summarize the current findings on the dynamic interconnection between TOR and these discrete phytoregulators and their potential role in executing diverse biological processes in plants.Item Cytokinin-mediated repression of anthocyanin biosynthesis in banana fruits(John Wiley & Sons, 2025) Rajput, Ruchika; Tyagi, Shivi; Anchal, Kumar; Singh, Samar; Laxmi, Ashverya; Misra, Prashant; Pandey, AshutoshAnthocyanins are pigments responsible for vibrant plant colors and play vital roles in plant physiology. This study compares two banana cultivars, Grand Naine (GN) and Red Banana (RB), which exhibit significant differences in anthocyanin pigmentation. Transcriptomic profiling of peel (PL) and pulp (PP) tissues revealed cytokinin-responsive type-B response regulators (RRs), MaRR_B9 and MaRR_B12, as key modulators of anthocyanin biosynthesis. Cytokinin treatment of PP tissues increased the expression of MaRR_B9 and MaRR_B12, while significantly reducing the expression of dihydroflavanol reductase (MaDFR1, MaDFR2) and anthocyanidin synthase (MaANS) genes along with anthocyanin content. Through a combination of physiological, molecular, and biochemical analyses, we demonstrate that MaRR_B9 and MaRR_B12 exert direct regulatory control over key structural genes of anthocyanin biosynthesis, MaDFRs and MaANS. Additionally, a type B-RRs motif (AGATT) was identified in the promoter regions of MaDFR2 and MaANS, suggesting that MaRRs might directly regulate the transcription of MaDFR2 and MaANS. MaRR_B9 and MaRR_B12 interact with the promoters of MaDFR2 and MaANS, repressing these genes in vivo. Overexpression of MaRR_B9 and MaRR_B12 in banana fruits leads to a reduction in anthocyanin content, notably the cyanidin derivative, accompanied by altered expression patterns of MaDFRs and MaANS. Thus, the present study identifies MaRR_B9 and MaRR_B12 as novel regulators of anthocyanin biosynthesis in banana and provides further evidence that the cytokinin regulatory network modifies anthocyanin accumulation in plants. In conclusion, our findings reveal new molecular targets, in the form of MaRRs, for the genetic optimization aimed at enhancing anthocyanin content, stress resilience, and nutritional value in crop plants.Item Nitric oxide-mediated thermomemory: a new perspective on plant heat stress resilience(Frontiers Media S.A., 2025) Naaz, Sheeba; Pande, Anjali; Laxmi, AshveryaIn the intricate world of plant responses to environmental stress, the concept of thermomemory has emerged as a fascinating and complex phenomenon. Plants, as sessile organisms, continually face the challenge of adapting to fluctuating climates, and the ability to "remember" prior heat stress encounters, a phenomenon known as thermomemory is a testament to their remarkable adaptability. Nitric oxide (NO), a versatile signaling molecule in plant physiology, has been implicated in a myriad of cellular processes crucial for stress adaptation. From its involvement in stomatal regulation to its influence on gene expression and antioxidant defense mechanisms, NO emerges as a central orchestrator in the plant's response to elevated temperatures. Exploration of NO-mediated pathways provides insights into how plants not only cope with immediate heat stress but also retain a memory of these encounters. Unraveling the molecular intricacies of NO's involvement in thermomemory enhances our understanding of the sophisticated strategies employed by plants to navigate a changing climate, offering potential avenues for innovative approaches to enhancing crop resilience and sustainable agriculture.Item Rooted in communication: Exploring auxin-salicylic acid nexus in root growth and development(John Wiley & Sons, 2025) Rawat, Sanjay Singh; Laxmi, AshveryaPlant hormones are pivotal in orchestrating diverse aspects of growth and developmental processes. Among various phytohormones, auxin and salicylic acid (SA) stand out as important regulators, often exerting opposing effects on overall plant growth. Essentially, research has indicated that auxin and SA-mediated pathways exhibit mutual antagonism during pathogen challenge. Additionally, in recent years, significant advancements have been made in uncovering the molecular intricacies that govern the action and interplay between these two phytohormones during various essential growth-related processes. In this discussion, we briefly delve into the genetic and molecular mechanisms involved in auxin and SA antagonism. We then analyse in detail how this dialogue impacts critical aspects of root development, with an emphasis on the transcriptional and protein regulatory networks. Finally, we propose the potential of exploring their interaction in various other aspects of below ground root growth processes. Understanding this relationship could provide valuable insights for optimizing and enhancing crop growth and yields.Item Molecular dialogue between light and temperature signaling in plants: From perception to thermotolerance(Oxford University Press, 2025) Sharma, Aishwarye; Samtani, Harsha; Laxmi, AshveryaLight and temperature are the two most variable environmental signals, which significantly regulate plant growth and development. Plants in the natural environment usually encounter warmer temperatures during the day and cooler temperatures at night, suggesting both light and temperature are closely linked signals. Due to global warming, it has become important to understand how light and temperature signaling pathways converge, and regulate plant development. This review outlines diverse mechanisms of light and temperature perception and downstream signaling, with an emphasis on their integration and interconnection. The recent research has highlighted the regulation of thermomorphogenesis by photoreceptors and their downstream light signaling proteins under different light conditions, and circadian clock components at warm temperatures. We have made an attempt to comprehensively describe these studies and demonstrate their connection with plant developmental responses. We have also explained how gene signaling pathways of light and thermomorphogenesis, are interconnected with HSR-mediated thermotolerance, which reveals new avenues to manipulate plants for climate resilience. In addition, the role of sugars as signaling molecules between light and temperature is also highlighted. Thus, we envisage that such detailed knowledge will enhance the understanding of how plants perceive light and temperature cues simultaneously and bring about responses that help in their adaptation.Item Complex genetic interaction between glucose sensor HXK1 and E3 SUMO ligase SIZ1 in regulating plant morphogenesis(Taylor & Francis Group, 2024) Rawat, Sanjay Singh; Sandhya, Shital; Laxmi, AshveryaSugar signaling forms the basis of metabolic activities crucial for an organism to perform essential life activities. In plants, sugars like glucose, mediate a wide range of physiological responses ranging from seed germination to cell senescence. This has led to the elucidation of cell signaling pathways involving glucose and its counterparts and the mechanism of how these sugars take control over major hormonal pathways such as auxin, ethylene, abscisic acid and cytokinin in Arabidopsis. Plants use HXK1(Hexokinase) as a glucose sensor to modulate changes in photosynthetic gene expression in response to high glucose levels. Other proteins such as SIZ1, a major SUMO E3 ligase have recently been implicated in controlling sugar responses via transcriptional and translational regulation of a wide array of sugar metabolic genes. Here, we show that these two genes work antagonistically and are epistatic in controlling responsiveness toward high glucose conditions.Item Sugar signals pedal the cell cycle!(Frontiers Media S.A., 2024) Rawat, Sanjay Singh; Laxmi, AshveryaCell cycle involves the sequential and reiterative progression of important events leading to cell division. Progression through a specific phase of the cell cycle is under the control of various factors. Since the cell cycle in multicellular eukaryotes responds to multiple extracellular mitogenic cues, its study in higher forms of life becomes all the more important. One such factor regulating cell cycle progression in plants is sugar signalling. Because the growth of organs depends on both cell growth and proliferation, sugars sensing and signalling are key control points linking sugar perception to regulation of downstream factors which facilitate these key developmental transitions. However, the basis of cell cycle control via sugars is intricate and demands exploration. This review deals with the information on sugar and TOR-SnRK1 signalling and how they manoeuvre various events of the cell cycle to ensure proper growth and development.Item Type-A response regulators negatively mediate heat stress response by altering redox homeostasis in Arabidopsis(Frontiers Media S.A., 2022) Jindal, Sunita; Kerchev, Pavel; Berka, Miroslav; Černý, Martin; Botta, Halidev Krishna; Laxmi, Ashverya; Brzobohatý, BřetislavBesides the long-standing role of cytokinins (CKs) as growth regulators, their current positioning at the interface of development and stress responses is coming into recognition. The current evidence suggests the notion that CKs are involved in heat stress response (HSR), however, the role of CK signaling components is still elusive. In this study, we have identified a role of the CK signaling components type-A Arabidopsis response regulators (ARRs) in HSR in Arabidopsis. The mutants of multiple type-A ARR genes exhibit improved basal and acquired thermotolerance and, altered response to oxidative stress in our physiological analyses. Through proteomics profiling, we show that the type-A arr mutants experience a 'stress-primed' state enabling them to respond more efficiently upon exposure to real stress stimuli. A substantial number of proteins that are involved in the heat-acclimatization process such as the proteins related to cellular redox status and heat shock, are already altered in the type-A arr mutants without a prior exposure to stress conditions. The metabolomics analyses further reveal that the mutants accumulate higher amounts of α-and γ-tocopherols, which are important antioxidants for protection against oxidative damage. Collectively, our results suggest that the type-A ARRs play an important role in heat stress response by affecting the redox homeostasis in Arabidopsis.