Institutional Publications
Permanent URI for this collectionhttps://ndkr-library.nipgr.ac.in/handle/123456789/11
Browse
7 results
Search Results
Item 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 A unique miR775-GALT9 module regulates leaf senescence in Arabidopsis during post-submergence recovery by modulating ethylene and the abscisic acid pathway(The Company of Biologists, 2022) Mishra, Vishnu; Singh, Archita; Gandhi, Nidhi; Das, Shabari Sarkar; Yadav, Sandeep; Kumar, Ashutosh; Sarkar, Ananda K.Submergence-induced hypoxic condition negatively affects the plant growth and development, and causes early onset of senescence. Hypoxia alters the expression of a number of microRNAs (miRNAs). However, the molecular function of submergence stress-induced miRNAs in physiological or developmental changes and recovery remains poorly understood. Here we show that miR775 is an Arabidopsis thaliana-specific young and unique miRNA that possibly evolved non-canonically. miR775 post-transcriptionally regulates Galactosyltransferase (GALT9) and their expression is inversely affected at 24 hours of complete submergence stress. The overexpression of miR775 (miR775-Oe) confers enhanced recovery from submergence stress and reduced accumulation of RBOHD and ROS, in contrast to wild type and MIM775 Arabidopsis shoot. A similar recovery phenotype of galt9 mutant indicates the role of miR775-GALT9 module in post-submergence recovery. We predicted Golgi-localized GALT9 to be potentially involved in protein glycosylation. The altered expression of senescence-associated genes (SAG12, SAG29, and ORE1), ethylene signalling (EIN2 and EIN3) and ABA biosynthesis (NCED3) pathway genes in miR775-Oe, galt9 and MIM775 plants. Thus, our results indicate the role of miR775-GALT9 module in post-submergence recovery through a crosstalk with ethylene and ABA pathway.Item Role of abiotic stress responsive miRNAs in Arabidopsis root development(Springer Nature Publishing AG, 2020) Singh, Archita; Gandhi, Nidhi; Mishra, Vishnu; Yadav, Sandeep; Rai, Vandna; Sarkar, Ananda K.Abiotic stresses like drought, extreme temperature, and lack of sufficient water or nutrients adversely affect plant growth and productivity. The physiological responses of higher plants to the environmental stresses are largely influenced by the root system, which can quickly modulate its developmental pattern under changing water, nutrient, and temperature, as an adaptive response. Protein coding genes, phytohormones and microRNAs (miRNAs) are among the key players which imparts crucial intrinsic role in shaping the root development and its environment adaptive growth pattern. Among these factors, miRNAs belong to a class of small non-coding RNAs of 21–24 nucleotides in length, which regulates various aspects of plant growth and development by negatively regulating their target genes through either transcriptional cleavage or translational inhibition. Although many miRNAs have been identified to be differentially regulated under various abiotic stress conditions, only a limited number of them have been characterized, due to the complex nature of its regulation. However, some of the miRNAs, such as miR156, miR165/166, miR169 etc., have recently been shown to be involved in both abiotic stress response and root development, indicating the diverse role of miRNA mediated gene regulation. The field of miRNA mediated gene regulation is dynamically expanding and more miRNAs are being characterized for their function. Current review focuses on miRNAs that are differentially regulated by major abiotic stresses as well as are involved in root development in Arabidopsis thaliana. We highlight their role in regulation of multiple and diverse aspects of developmental and physiological processes in Arabidopsis.Item Role of chromatin modification and remodeling in stem cell regulation and meristem maintenance in Arabidopsis(Oxford University Press, 2020) Singh, Sharmila; Singh, Alka; Singh, Archita; Mahima; Yadav, Sandeep; Bajaj, Ishita; Kumar, Shailendra; Jain, Ajay; Sarkar, Ananda K.In higher plants, pluripotent stem cells reside in the specialized microenvironment called stem cell niches (SCNs) harbored at the shoot apical meristem (SAM) and root apical meristem (RAM), which give rise to the aerial and underground parts of a plant, respectively. The model plant Arabidopsis thaliana (Arabidopsis) has been extensively studied to decipher the intricate regulatory mechanisms involving some key transcriptions factors and phytohormones that play pivotal roles in stem cell homeostasis, meristem maintenance, and organ formation. However, there is increasing evidence to show the epigenetic regulation of the chromatin architecture, gene expression exerting an influence on an innate balance between the self-renewal of stem cells, and differentiation of the progeny cells to a specific tissue type or organ. Post-translational histone modifications, ATP-dependent chromatin remodeling, and chromatin assembly/ disassembly are some of the key features involved in the modulation of chromatin architecture. Here, we discuss the major epigenetic regulators and illustrate their roles in the regulation of stem cell activity, meristem maintenance, and related organ patterning in Arabidopsis.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.Item Whole mount in situ localization of miRNAs and target mRNA transcripts in plants(Springer Nature Publishing AG, 2019) Gautam, Vibhav; Singh, Archita; Verma, Swati; Singh, Sharmila; Chatterjee, Sourav; Sarkar, Ananda K.The functional characterization of miRNAs often involves understanding of their spatiotemporal expression, which mostly relies on reporter-based or in situ hybridization studies. The available in situ localization methods follow separate protocols for pre-hybridization, hybridization, post-hybridization, and detection steps for both miRNA and mRNA transcripts in plants. In this study, we present a single method which can be used for whole mount in situ localization of both miRNAs and mRNAs in different plant tissues. Our modified method provides enhanced sensitivity for the localization of miRNA and their target transcripts. Consequently, a less laborious, time-saving, economic and efficient method has been proposed by the modification of pre-hybridization, hybridization, post-hybridization and detection steps.Item SWP1 negatively regulates lateral root initiation and elongation in Arabidopsis(Landes Bioscience, 2012) Singh, Sharmila; Singh, Archita; Roy, Shradha; Sarkar, Ananda K.The main root and continuously emerging lateral roots constitute the root architecture of an adult plant during its postembryonic development. Epigenetic modifications like methylation or deacetylation of histones have been suggested to regulate root development. SWP1/LDL1, a component of plant specific corepressor complex, has been implicated in the induction of flowers and root through histone modifications in Arabidopsis. However, molecular role of SWP1 in regulating the lateral root development remained unexplored. Here we show that SWP1 regulates lateral root initiation and elongation in Arabidopsis. Mutation in SWP1 increases both the density and length of lateral roots. SWP1 negatively regulates lateral root initiation through direct/indirect transcriptional repression of lateral root promoting factors, such as AUXIN RESPONSE FACTORS (ARFs) and GATA23.