Publications of NIPGR Scientists

Permanent URI for this communityhttps://ndkr-library.nipgr.ac.in/handle/123456789/1

Browse

Author: search.filters.author.Giri, JitenderSubject: search.filters.subject.root

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    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, Jitender
    Glycerophosphodiester 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.
  • Thumbnail Image
    Item
    A novel glycerophosphodiester phosphodiesterase improves phosphate deficiency tolerance in rice
    (John Wiley & Sons, 2019) Mehra, Poonam; Pandey, Bipin K.; Verma, Lokesh; Giri, Jitender
    Soil phosphate (Pi) deficiency is major constraint for rice cultivation world‐wide. Cellular membranes account for one‐third of cellular P (Phosphorus) in the form of phospholipids. Therefore, remobilization of Pi from membrane phospholipids under Pi deficiency can be an important strategy to improve PUE (Phosphorus Use Efficiency). GDPDs (Glycerophosphodiester phosphodiesterases) hydrolyse intermediate product of phospholipid catabolism, glycerophosphodiesters to glycerol‐3‐phosphate (G3P); a precursor for P and non P‐lipid biosynthesis. Here, we show that OsGDPD2 is a Pi deficiency responsive gene which is transcriptionally regulated by OsPHR2. In silico analysis of active site residues and enzymatic assays confirmed phosphodiesterase activity of OsGDPD2. All overexpression lines showed higher GDPD activity, Pi content, root growth and biomass accumulation as compared to wild‐type. Conversely, silencing of OsGDPD2 led to decreased GDPD activity and Pi content. Notably, most of the P‐containing metabolites and fatty acids were elevated in transgenic lines. Further, quantitative analysis of polar lipids revealed higher accumulation of several classes of phospholipids and galactolipids in overexpression lines indicating a potential role of OsGDPD2 in de novo glycerolipid biosynthesis. Thus, present study provides insights into novel physiological roles of OsGDPD2 in low Pi acclimation in rice.
  • Thumbnail Image
    Item
    JAZ repressors: Potential involvement in nutrients deficiency response in rice and chickpea
    (Frontiers Media S.A., 2015) Singh, Ajit P.; Pandey, Bipin K.; Deveshwar, Priyanka; Narnoliya, Laxmi; Parida, Swarup K.; Giri, Jitender
    Jasmonates (JA) are well-known phytohormones which play important roles in plant development and defense against pathogens. Jasmonate ZIM domain (JAZ) proteins are plant-specific proteins and act as transcriptional repressors of JA-responsive genes. JA regulates both biotic and abiotic stress responses in plants; however, its role in nutrient deficiency responses is very elusive. Although, JA is well-known for root growth inhibition, little is known about behavior of JAZ genes in response to nutrient deficiencies, under which root architectural alteration is an important adaptation. Using protein sequence homology and a conserved-domains approach, here we identify 10 novel JAZ genes from the recently sequenced Chickpea genome, which is one of the most nutrient efficient crops. Both rice and chickpea JAZ genes express in tissue- and stimuli-specific manners. Many of which are preferentially expressed in root. Our analysis further showed differential expression of JAZ genes under macro (NPK) and micronutrients (Zn, Fe) deficiency in rice and chickpea roots. While both rice and chickpea JAZ genes showed a certain level of specificity toward type of nutrient deficiency, generally majority of them showed induction under K deficiency. Generally, JAZ genes showed an induction at early stages of stress and expression declined at later stages of macro-nutrient deficiency. Our results suggest that JAZ genes might play a role in early nutrient deficiency response both in monocot and dicot roots, and information generated here can be further used for understanding the possible roles of JA in root architectural alterations for nutrient deficiency adaptations.