Publications of NIPGR Scientists
Permanent URI for this communityhttps://ndkr-library.nipgr.ac.in/handle/123456789/1
Browse
19 results
Search Results
Item Phosphate deficiency inducible OsGDPD5 affects root growth by regulating sugar-auxin crosstalk(John Wiley & Sons, 2025) Verma, Lokesh; Pandey, Mandavi; Bhatia, Chitra; Mehra, Poonam; Singh, Bhagat; Giri, JitenderGlycerophosphodiester phosphodiesterases (GDPDs) enzymes are known to be involved in phospholipids degradation pathways, where glycerophosphodiesters are hydrolyzed to glycerol-3-phosphate (G3P) and corresponding alcohol. In plants, GDPDs are involved in phosphate deficiency adaptive responses and have been shown to impact root length, but the precise mechanism remains unclear. This study focuses on the rice GDPD5 gene and its role in regulating primary root growth. Our research demonstrates that OsGDPD5 encodes a functional GDPD enzyme and could hydrolyze glycerophosphocholine and glycerophosphorylethanolamine. At transcriptional levels, OsGDPD5 is preferentially expressed in the root tip and regulated by transcription factor OsPHR2. We have used CRISPR/Cas9 to generate OsGDPD5 knock-out lines, allowing us to explore its role in root growth. Our findings show that osgdpd5 mutants had a shorter primary root, which could be restored to a normal level by the exogenous application of sugar or G3P. Further, knocking out OsGDPD5 alters endogenous levels of G3P and sugars, affecting auxin biosynthesis in the root and, ultimately, primary root growth. In this manner, OsGDPD5 has a crucial role in regulating physiological processes, specifically sugar and auxin signaling, which are known to be involved in root growth regulation in rice. Our research thus unraveled a link between rice phosphate deficiency-responsive lipid remodeling and root growth via sugar-hormone signaling.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 Diverse roles of phytohormonal signaling in modulating plant-virus interaction(Oxford University Press, 2025) Sharma, Shambhavi; Prasad, ManojVirus infection brings about changes in the transcriptome, proteome and metabolome status of the infected plant wherein substantial alterations in the abundance of phytohormones and associated components involved in their signaling pathways have been observed. In the recent years, extensive research in the field of plant virology has showcased the undisputable significance of phytohormone signaling during plant-virus interactions. Apart from acting as growth regulators, phytohormones elicit robust immune response, which restricts the viral multiplication within the plant as well as its propagation by vector. Interestingly, these pathways have been shown to not only act as isolated mechanisms but as complex intertwined regulatory cascades where, the cross-talk among different phytohormones and with other antiviral pathways takes place during plant-virus interplay. Viruses cleverly disrupt phytohormone homeostasis via their multifunctional effectors that seems to be smart approach adopted by viruses to circumvent phytohormone-mediated plant immune responses. In this review, we summarize the current understanding of role of phytohormone signaling pathways during plant-virus interaction in activating antiviral immune responses of plant and also, how viruses exploit these signaling pathways favoring their pathogenesis.Item A lipid synthase maintains metabolic flux for jasmonate synthesis to regulate root growth and phosphate homeostasis(Oxford University Press, 2025) Pandey, Mandavi; Verma, Lokesh; Kohli, Pawandeep Singh; Singh, Bhagat; Kochi, Abhijith; Giri, JitenderPlants require phosphate (Pi) for proper growth and development but often face scarcity of this vital nutrient in the soil. Pi-starvation triggers membrane lipid remodeling to utilize the membrane phospholipid-bound Pi in plants. In this process, phospholipids are replaced by non-Pi-containing galactolipids (MGDG, DGDG) and sulfolipids. The galactolipids ratio (MGDG:DGDG) is suggested to influence jasmonic acid (JA) biosynthesis. However, how the MGDG:DGDG ratio, JA levels, and root growth are coordinated under Pi deficiency in rice (Oryza sativa) remains unknown. Here, we characterized DGDG synthase 1 (OsDGD1) for its role in regulating root development by maintaining metabolic flux for JA biosynthesis. We showed that OsDGD1 is responsive under low Pi and is under the direct control of Phosphate Starvation Response 2 (OsPHR2), the master regulator of low Pi adaptations. Further, OsDGD1 knockout (KO) lines showed marked phenotypic differences compared to the wild type (WT), including a significant reduction in root length and biomass, leading to reduced Pi uptake. Further, lipidome analyses revealed reduced DGDG levels in the KO line, leading to reduced membrane remodeling, thus affecting P utilization efficiency. We also observed an increase in the MGDG: DGDG ratio in KO lines, which enhanced the endogenous JA levels and signaling. This imbalance of JA in KO plants led to changes in auxin levels, causing drastic root growth inhibition. These findings indicate the critical role of OsDGD1 in maintaining optimum levels of JA during Pi deficiency for conducive root growth. Besides acting as signaling molecules and structural components, our study widens the role of lipids as metabolic flux controllers for phytohormone biosynthesis.Item Role of transcriptional regulation in auxin-mediated response to abiotic stresses(Frontiers Media S.A., 2024) Marzi, Davide; Brunetti, Patrizia; Saini, Shashank Sagar; Yadav, Gitanjali; Puglia, Giuseppe Diego; Dello, Ioio RaffaeleGlobal climate change (GCC) is posing a serious threat to organisms, particularly plants, which are sessile. Drought, salinity, and the accumulation of heavy metals alter soil composition and have detrimental effects on crops and wild plants. The hormone auxin plays a pivotal role in the response to stress conditions through the fine regulation of plant growth. Hence, rapid, tight, and coordinated regulation of its concentration is achieved by auxin modulation at multiple levels. Beyond the structural enzymes involved in auxin biosynthesis, transport, and signal transduction, transcription factors (TFs) can finely and rapidly drive auxin response in specific tissues. Auxin Response Factors (ARFs) such as the ARF4, 7, 8, 19 and many other TF families, such as WRKY and MADS, have been identified to play a role in modulating various auxin-mediated responses in recent times. Here, we review the most relevant and recent literature on TFs associated with the regulation of the biosynthetic, transport, and signalling auxin pathways and miRNA-related feedback loops in response to major abiotic stresses. Knowledge of the specific role of TFs may be of utmost importance in counteracting the effects of GCC on future agriculture and may pave the way for increased plant resilience.Item Characterization and expression profiling of PIN auxin efflux transporters reveal their role in developmental and abiotic stress conditions in rice(Frontiers Media S.A., 2022) Manna, Mrinalini; Rengasamy, Balakrishnan; Ambasht, Navin Kumar; Sinha, Alok KrishnaThe auxin efflux transporter proteins called PINs ferry auxin from its source to sinks in particular directions depending on their polar localizations in the plasma membrane, thus facilitating the development of the entire plant architecture. The rice genome has 12 PIN genes distributed over eight chromosomes. To study their roles in plant development, abiotic stress responsiveness, and shaping an auxin-dependent root architecture, a genome-wide analysis was carried out. Based on phylogeny, cellular localization, and hydrophilic loop domain size, the PINs were categorized into canonical and noncanonical PINs. PINs were found expressed in all of the organs of plants that emphasized their indispensable role throughout the plant's life cycle. We discovered that PIN5C and PIN9 were upregulated during salt and drought stress. We also found that regardless of its cellular level, auxin functioned as a molecular switch to turn on auxin biosynthesis genes. On the contrary, although PIN expression was upregulated upon initial treatment with auxin, prolonged auxin treatment not only led to their downregulation but also led to the development of auxin-dependent altered root formation in rice. Our study paves the way for developing stress-tolerant rice and plants with a desirable root architecture by genetic engineeringItem Potassium chloroaurate-mediated in vitro synthesis of gold nanoparticles improved root growth by crosstalk with sucrose and nutrient-dependent auxin homeostasis in Arabidopsis thaliana(MDPI AG, 2022) Yadav, Sandeep; Yugandhar, Poli; Alavilli, Hemasundar; Raliya, Ramesh; Singh, Archita; Sahi, Shivendra V.; Sarkar, Ananda K.; Jain, AjayIn a hydroponic system, potassium chloroaurate (KAuCl4 ) triggers the in vitro sucrose (Suc)-dependent formation of gold nanoparticles (AuNPs). AuNPs stimulate the growth of the root system, but their molecular mechanism has not been deciphered. The root system of Arabidopsis (Arabidopsis thaliana) exhibits developmental plasticity in response to the availability of various nutrients, Suc, and auxin. Here, we showed the roles of Suc, phosphorus (P), and nitrogen (N) in facilitating a AuNPs-mediated increase in root growth. Furthermore, the recuperating effects of KAuCl4 on the natural (IAA) auxin-mediated perturbation of the root system were demonstrated. Arabidopsis seedlings harboring the cell division marker CycB1;1::CDB-GUS provided evidence of the restoration efficacy of KAuCl4 on the IAA-mediated inhibitory effect on meristematic cell proliferation of the primary and lateral roots. Arabidopsis harboring synthetic auxin DR5rev::GFP exhibited a reinstating effect of KAuCl4 on IAA-mediated aberration in auxin subcellular localization in the root. KAuCl4 also exerted significant and differential recuperating effects on the IAA-mediated altered expression of the genes involved in auxin signaling and biosynthetic pathways in roots. Our results highlight the crosstalk between KAuCl4 -mediated improved root growth and Suc and nutrient-dependent auxin homeostasis in Arabidopsis.Item MEDIATOR SUBUNIT17 integrates jasmonate and auxin signaling pathways to regulate thermomorphogenesis(Oxford University Press, 2022) Agrawal, Rekha; Sharma, Mohan; Dwivedi, Nidhi; Maji, Sourobh; Thakur, Pallabi; Junaid, Alim; Fajkus, Jiří; Laxmi, Ashverya; Thakur, Jitendra K.Plant adjustment to environmental changes involves complex crosstalk between extrinsic and intrinsic cues. In the past two decades, extensive research has elucidated the key roles of PHYTOCHROME INTERACTING FACTOR4 (PIF4) and the phytohormone auxin in thermomorphogenesis. In this study, we identified a previously unexplored role of jasmonate (JA) signaling components, the Mediator complex, and their integration with auxin signaling during thermomorphogenesis in Arabidopsis (Arabidopsis thaliana). Warm temperature induces expression of JA signaling genes including MYC2, but, surprisingly, this transcriptional activation is not JA dependent. Warm temperature also promotes accumulation of the JA-signaling receptor CORONATINE INSENSITIVE1 (COI1) and degradation of the JA-signaling repressor JASMONATE-ZIM-DOMAIN PROTEIN9 (JAZ9), which probably leads to de-repression of MYC2, enabling it to contribute to the expression of MEDIATOR SUBUNIT17 (MED17). In response to warm temperature, MED17 occupies the promoters of thermosensory genes including PIF4, YUCCA8 (YUC8), INDOLE-3-ACETIC ACID INDUCIBLE19 (IAA19), and IAA29. Moreover, MED17 facilitates enrichment of H3K4me3 on the promoters of PIF4, YUC8, IAA19, and IAA29 genes. Interestingly, both occupancy of MED17 and enrichment of H3K4me3 on these thermomorphogenesis-related promoters are dependent on PIF4 (or PIFs). Altered accumulation of COI1 under warm temperature in the med17 mutant suggests the possibility of a feedback mechanism. Overall, this study reveals the role of the Mediator complex as an integrator of JA and auxin signaling pathways during thermomorphogenesis.Item Dynamics of miRNA mediated regulation of legume symbiosis(John Wiley & Sons, 2021) Tiwari, Manish; Pandey, Vimal; Singh, Baljinder; Bhatia, SabhyataSymbiotic nitrogen fixation in legume nodules is important in soils with low nitrogen availability. The initiation and sustainability of symbiosis requires cellular reprogramming that involves the miRNA‐mediated inhibition or activation of specific nodulation genes. The high‐throughput sequencing of small RNA libraries has identified miRNAs and their targets, which are the major players in the post‐transcriptional gene regulation (PTGS) of the different stages of legume‐rhizobia symbiosis ranging from bacterial colonization and organogenesis to symbiotic nitrogen fixation. Here we present an overview of information obtained from the miRNA libraries from nodulating tissues that have been sequenced to date. The functional analysis of miRNAs has revealed roles in phytohormone homeostasis and spatio‐temporal regulation, as well as the mobility of miRNAs and their functions in shoot to root signalling that affects diverse functions, including bacterial entry, meristem division and differentiation, nitrogen fixation and senescence. Furthermore, small RNA fragments of rhizobial origin repress complementary plant mRNAs. We also consider the roles of miRNAs in determinate or indeterminate nodules. Taken together, this overview confirms that miRNAs are master regulators of the legume‐rhizobia symbiosis.Item Auxin signaling modulates LATERAL ROOT PRIMORDIUM1 (LRP1) expression during lateral root development in Arabidopsis(John Wiley & Sons, 2020) Singh, Sharmila; Yadav, Sandeep; Singh, Alka; Mahima; Singh, Archita; Gautam, Vibhav; Sarkar, Ananda K.Auxin signaling mediated by various Auxin/Indole-3-Acetic Acid (Aux/IAAs) and AUXIN RESPONSE FACTORs (ARFs) regulate lateral root (LR) development by controlling the expression of downstream genes. LATERAL ROOT PRIMORDIUM1 (LRP1), a member of SHORT INTERNODES/STYLISH (SHI/STY) family, was identified as an auxin inducible gene. Precise developmental role and molecular regulation of LRP1 in root development remains to be understood. Here we show that LRP1 is expressed in all stages of LR development, besides primary root. The expression of LRP1 is regulated by histone deacetylation in an auxin dependent manner. Our genetic interaction studies showed that LRP1 acts downstream of auxin responsive Aux/IAAs-ARFs modules during LR development. We showed that auxin mediated induction of LRP1 is lost in slr-1 and arf7arf19 mutants roots. NPA treatment studies showed that LRP1 acts after LR founder cell specification and asymmetric division. Overexpression of LRP1 (LRP1 OE) showed increased number of LRPs at stage I, IV and V, resulting in reduced emerged LR density, which suggests that it is involved in LRP development. Interestingly, LRP1 induced expression of YUC4, which is involved in auxin biosynthesis, contributes to increased accumulation of endogenous auxin in LRP1 OE roots. LRP1 interacts with SHI, STY1, SRS3 and SRS7 proteins of SHI/STY family indicating their possible redundant role during root development. Our results suggest that auxin and histone deacetylation affect LRP1 expression, and it acts downstream of LR forming auxin response modules to negatively regulate LRP development by modulating auxin homeostasis in Arabidopsis thaliana.