Institutional Publications

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    Unearthing root response mechanisms to soil compaction in legumes
    (John Wiley & Sons, 2026) Ganotra, Jahanvi; Pandey, Mandavi; Pandey, Bipin K.; Giri, Jitender
    Roots are essential for the survival and functioning of plants, serving as anchors in the soil and drawing in vital nutrients and water. Roots also engage in diverse microbial interactions, including pathogenic interactions that cause plant disease and non-pathogenic interactions, such as symbiotic and commensal relationships. Mechanical resistance in compacted soil is one of the biggest challenges for root exploration. Soil compaction hampers plant growth by restricting root elongation, reducing root proliferation, and limiting access to water, nutrients, and oxygen. These restrictions interfere with root-microbe interactions and also impair aboveground growth, leading to decreased shoot biomass, stunted development, and lower overall productivity. Legume roots form symbiotic relationships with soil-dwelling Rhizobium, resulting in root nodules that convert atmospheric nitrogen (N) into ammonia, thereby promoting plant growth. However, the impact of soil compaction on legume roots remains poorly studied. In this review, we examine key adaptive strategies used by legume roots to counteract soil compaction, focusing on the underlying molecular pathways. A complex signalling network regulates molecular processes that control root development and nodulation in legumes. We also explore the genetic and environmental factors that influence morphological, anatomical, and biochemical traits under mechanical stress, providing insights for improving stress resilience in legumes.
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    The host and pathogen myo-inositol-1-phosphate synthases are required for Rhizoctonia solani AG1-IA infection in tomato
    (John Wiley & Sons, 2024) Tyagi, Kriti; Chandan, Ravindra K.; Sahoo, Debashis; Ghosh, Srayan; Gupta, Santosh Kumar; Jha, Gopaljee
    The myo-inositol-1-phosphate synthase (MIPS) catalyses the biosynthesis of myo-inositol, an important sugar that regulates various physiological and biochemical processes in plants. Here, we provide evidence that host (SlMIPS1) and pathogen (Rs_MIPS) myo-inositol-1-phosphate synthase (MIPS) genes are required for successful infection of Rhizoctonia solani, a devastating necrotrophic fungal pathogen, in tomato. Silencing of either SlMIPS1 or Rs_MIPS prevented disease, whereas an exogenous spray of myo-inositol enhanced disease severity. SlMIPS1 was upregulated upon R. solani infection, and potentially promoted source-to-sink transition, induced SWEET gene expression, and facilitated sugar availability in the infected tissues. In addition, salicylic acid (SA)-jasmonic acid homeostasis was altered and SA-mediated defence was suppressed; therefore, disease was promoted. On the other hand, silencing of SlMIPS1 limited sugar availability and induced SA-mediated defence to prevent R. solani infection. Virus-induced gene silencing of NPR1, a key gene in SA signalling, rendered SlMIPS1-silenced tomato lines susceptible to infection. These analyses suggest that induction of SA-mediated defence imparts disease tolerance in SlMIPS1-silenced tomato lines. In addition, we present evidence that SlMIPS1 and SA negatively regulate each other to modulate the defence response. SA treatment reduced SlMIPS1 expression and myo-inositol content in tomato, whereas myo-inositol treatment prevented SA-mediated defence. We emphasize that downregulation of host/pathogen MIPS can be an important strategy for controlling diseases caused by R. solani in agriculturally important crops.
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    Editorial: Plant transcription factors associated with abiotic stress tolerance in crops and wild-relatives
    (Frontiers Media S.A., 2024) Puglia, Giuseppe Diego; Frugis, Giovanna; Yadav, Gitanjali
    Editorial on the Research Topic Plant transcription factors associated with abiotic stress tolerance in crop and wild-relatives Global climate change (GCC), by altering the intensity and frequency of potentially damaging weather events such as droughts, waterlogging, heat waves, and cold spells, has altered seasonal weather patterns, causing severe problems for plant crops and wildlife species (Cramer et al., 2011; Asseng et al., 2015; Minoli et al., 2019). To cope with these challenges, plants have evolved complex regulatory mechanisms that enable them to respond and adapt to changing environmental conditions, while maintaining a balance between optimal growth and stress (Eckardt et al., 2023). This Research Topic brings together several contributions that highlight the role of transcriptional regulation in plant responses to abiotic stresses and hypothesise its role in stress tolerance. The studies published in this Research Topic deal with well-recognised groups of transcription factors (TFs), but also with new ones whose association with the response to abiotic stresses has been demonstrated by recent molecular advances. This evidence allows us to shed light on the mechanisms by which plants respond to different stresses, with a focus on abiotic stresses such as salt, drought, cold, and waterlogging.
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    Plant phosphate status influences root biotic interactions
    (Oxford University Press, 2023) Pazhamala, Lekha T; Giri, Jitender
    Phosphorus (P) deficiency stress in combination with biotic stress(s) severely impacts crop yield. Plant responses to P deficiency overlapping with that of other stresses exhibit a high degree of complexity involving different signaling pathways. On one hand, plants engage with rhizosphere microbiome/ arbuscular mycorrhizal fungi for improved phosphate (Pi) acquisition and plant stress response upon Pi deficiency, on the other, this association is inhibited under Pi sufficiency. This nutrient-dependent response is highly regulated by phosphate starvation response (PSR) mediated by the master regulator, PHR1 and its homolog, PHL. It is interesting to note that Pi status (deficiency/sufficiency) has a varying response (positive/negative) to different biotic encounters (beneficial microbes/opportunistic pathogens/insect herbivory), through a coupled PSR-PHR1-immune response. This also involves crosstalk among multiple players including transcription factors, defense hormones, microRNAs, and phosphate transporters, among others influencing the plant-biotic-phosphate interactions. We provide a comprehensive view of these key players involved in maintaining a delicate balance between Pi homeostasis and plant immunity. Finally, we propose strategies to utilize this information to improve crop resilience to P deficiency in combination with biotic stresses.
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    Jasmonic acid coordinates with light, glucose and auxin signalling in regulating branching angle of Arabidopsis lateral roots
    (John Wiley & Sons, 2022) Sharma, Manvi; Sharma, Mohan; Jamsheer, K. Muhammed; Laxmi, Ashverya
    The role of jasmonates (JAs) in primary root growth and development and in plant response to external stimuli is already known. However, its role in lateral root (LR) development remains to be explored. Our work identified methyl jasmonate (MeJA) as a key phytohormone in determining the branching angle of Arabidopsis LRs. MeJA inclines the LRs to a more vertical orientation, which was dependent on the canonical JAR1-COI1-MYC2,3,4 signalling. Our work also highlights the dual roles of light in governing LR angle. Light signalling enhances JA biosynthesis, leading to erect root architecture; whereas, glucose (Glc) induces wider branching angles. Combining physiological and molecular assays, we revealed that Glc antagonizes the MeJA response via TARGET OF RAPAMYCIN (TOR) signalling. Moreover, physiological assays using auxin mutants, MYC2-mediated transcriptional activation of LAZY2, LAZY4 and auxin biosynthetic gene CYP79B2,and asymmetric distribution of DR5::GFP and PIN2::GFP pinpointed the role of an intact auxin mechanism required by MeJA for vertical growth of LRs. We also demonstrated that light perception and signalling are indispensable for inducing vertical angles by MeJA. Thus, our investigation highlights antagonism between light and Glc signalling and how they interact with JA-auxin signals to optimize the branching angle of LRs.
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    Progress and prospects of concurrent or combined stress studies in plants
    (John Wiley & Sons, 2021) Mahalingam, Ramamurthy; Pandey, Prachi; Senthil-Kumar, Muthappa
    Plants growing under field conditions are often exposed to multiple abiotic and biotic stresses occurring simultaneously or sequentially. Biotic stressors often interact with abiotic stressors at the plant interphase, which makes the impact of their combination on plants remarkably variable, though differing with order and intensity of stresses, as well as plant species and pathotypes. In this article, we examine the major abiotic stress combinations, as well as abiotic-biotic stress combinations, and physiological and molecular responses of plants to these combined stresses. Utilizing the available literature, information on the phenomic and transcriptomic response of plants to the combined abiotic and biotic stresses, and the cross-talk during signalling is reviewed. A succinct discussion on the scope and application of combined abiotic and biotic stress studies highlighting major gaps and novel avenues for further research is articulated.
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    The versatile role of glucose signalling in regulating growth, development and stress responses in plants
    (Springer Nature Publishing AG, 2020) Saksena, Harshita B.; Sharma, Manvi; Singh, Dhriti; Laxmi, Ashverya
    Sugars as an energy source and a signalling molecule are indispensible for growth, development and stress responses in plants. Among sugars, glucose (Glc) has been identified to perform a key role in regulating various cellular and developmental processes in plants. This comprehensive review highlights the crosstalk of glucose signalling with auxin, cytokinin and brassinosteroid signalling in controlling several aspects of plant development including root growth deviation, root waving and coiling, lateral root emergence, hypocotyl elongation, etc. through a Hexokinase 1 dependent and independent pathway in Arabidopsis. It also provides an insight on the role of Glc-mediated target of rapamycin signalling in modulating various abiotic stresses like nutrient deficiency stress, heat stress, oxidative stress etc. The review also discusses about sugar inducible FCS-Like Zinc Finger genes in modulating SNF1-related protein kinase 1 signalling to coordinate growth and stress responses in plants. Therefore, glucose signalling in concert with diverse signalling pathways and via regulating certain genes contributes to numerous cellular processes to control development and stress responses in plants.
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    Striking the right chord: Signaling enigma during root gravitropism
    (Frontiers Media S.A., 2017) Singh, Manjul; Gupta, Aditi; Laxmi, Ashverya
    Plants being sessile can often be judged as passive acceptors of their environment. However, plants are actually even more active in responding to the factors from their surroundings. Plants do not have eyes, ears or vestibular system like animals, still they "know" which way is up and which way is down? This is facilitated by receptor molecules within plant which perceive changes in internal and external conditions such as light, touch, obstacles; and initiate signaling pathways that enable the plant to react. Plant responses that involve a definite and specific movement are called "tropic" responses. Perhaps the best known and studied tropisms are phototropism, i.e., response to light, and geotropism, i.e., response to gravity. A robust root system is vital for plant growth as it can provide physical anchorage to soil as well as absorb water, nutrients and essential minerals from soil efficiently. Gravitropic responses of both primary as well as lateral root thus become critical for plant growth and development. The molecular mechanisms of root gravitropism has been delved intensively, however, the mechanism behind how the potential energy of gravity stimulus converts into a biochemical signal in vascular plants is still unknown, due to which gravity sensing in plants still remains one of the most fascinating questions in molecular biology. Communications within plants occur through phytohormones and other chemical substances produced in plants which have a developmental or physiological effect on growth. Here, we review current knowledge of various intrinsic signaling mechanisms that modulate root gravitropism in order to point out the questions and emerging developments in plant directional growth responses. We are also discussing the roles of sugar signals and their interaction with phytohormone machinery, specifically in context of root directional responses.