Institutional Publications

Permanent URI for this collectionhttps://ndkr-library.nipgr.ac.in/handle/123456789/11

Browse

Author: search.filters.author.Mehra, PoonamSubject: search.filters.subject.Root

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Morpho-physiological and transcriptome profiling reveal novel zinc deficiency-responsive genes in rice
    (Springer, 2017) Bandyopadhyay, Tirthankar; Mehra, Poonam; Hairat, Suboot; Giri, Jitender
    Intensive farming has depleted the soil zinc (Zn) availability resulting in decreased crop productivity. Here, we attempt to understand the Zn deficiency response in rice through temporal transcriptome analysis. For this, rice seedlings were raised under Zn-deficient conditions up to 4 weeks followed by Zn re-supply for 3 days. Zn-deficient plants developed characteristic deficiency symptoms such as leaf bronzing, decrease in biomass, total chlorophyll, PSII efficiency, decreased carbonic anhydrase activity and increased ROS production. Interestingly, severe alterations in root system architecture were also observed. Comprehensive transcriptome analyses of rice seedlings were carried out after 2 (DEF2W) and 4 weeks (DEF4W) of Zn deficiency with respect to transcriptome profiles of corresponding Zn sufficient conditions (SUF2W, SUF4W). Additionally, to detect the potential Zn-responsive genes, transcriptome profile of Zn-recovered seedlings was compared with DEF4W. All differentially expressed Zn-responsive genes were categorized into early and late Zn deficiency response, and a set of 77 genes, induced and repressed on Zn deficiency and re-supply, respectively, was identified. These genes could be used as low Zn-responsive marker genes. Further, genes involved in membrane transport, phytosiderophore activity and organic acid biosynthesis showed high differential expression. Additionally, the present study unravelled several genes putatively associated with alterations in root system architecture under Zn deficiency and provides novel insights into the interpretation of morpho-physiological, biochemical and molecular regulation of zinc deficiency responses in rice.
  • Thumbnail Image
    Item
    Improvement of phosphate acquisition and utilization by a secretory purple acid phosphatase (OsPAP21b) in rice
    (John Wiley & Sons, 2017) Mehra, Poonam; Pandey, Bipin Kumar; Giri, Jitender
    Phosphate (Pi) deficiency in soil system is a limiting factor for rice growth and yield. Majority of the soil Phosphorus (P) is organic in nature; not readily available for root uptake. Low Pi inducible purple acid phosphatases (PAPs) are hypothesized to enhance the availability of Pi in soil and cellular system. However, information on molecular and physiological roles of rice PAPs is very limited. Here, we demonstrate the role of a novel rice PAP, OsPAP21b in improving plant utilization of organic-P. OsPAP21b was found to be under the transcriptional control of OsPHR2 and strictly regulated by plant Pi-status at both transcript and protein levels. Biochemically, OsPAP21b showed hydrolysis of several organophosphates at acidic pH and possessed sufficient thermostability befitting for high temperature rice ecosystems with acidic soils. Interestingly, OsPAP21b was revealed to be a secretory PAP and encodes a distinguishable major APase (acid phosphatase) isoform under low Pi in roots. Further, OsPAP21b overexpressing transgenics showed increased biomass, APase activity and P content both in hydroponics supplemented with organic-P sources and soil containing organic manure as sole P source. Additionally, overexpression lines depicted increased root length, biomass and lateral roots under low Pi while RNAi lines showed reduced root length and biomass as compared to WT. In light of these evidences, present study strongly proposes OsPAP21b as a useful candidate for improving Pi acquisition and utilization in rice.