http://192.168.1.40:8080/xmlui/handle/123456789/1132 2026-05-31T16:55:43Z 2026-05-31T16:55:43Z Sengupta, Sonali Patra, Barunava Ray, Sudipta Majumder, Arun Lahiri http://192.168.1.40:8080/xmlui/handle/123456789/1851 2013-02-08T05:52:02Z 2008-10-01T00:00:00Z

Inositol methyl tranferase from a halophytic wild rice, Porteresia coarctata Roxb. (Tateoka): regulation of pinitol synthesis under abiotic stress Sengupta, Sonali; Patra, Barunava; Ray, Sudipta; Majumder, Arun Lahiri Methylated inositol D-pinitol (3-O-methyl-D-chiro-inositol) accumulates in a number of plants naturally or in response to stress. Here, we present evidence for accumulation and salt-enhanced synthesis of pinitol in Porteresia coarctata, a halophytic wild rice, in contrast to its absence in domesticated rice. A cDNA for Porteresia coarctata inositol methyl transferase 1 (PcIMT1), coding for the inositol methyl transferase implicated in the synthesis of pinitol has been cloned from P. coarctata, bacterially overexpressed and shown to be functional in vitro. In silico analysis confirms the absence of an IMT1 homolog in Oryza genome, and PcIMT1 is identified as phylogenetically remotely related to the methyl transferase gene family in rice. Both transcript and proteomic analysis show the up-regulation of PcIMT1 expression following exposure to salinity. Coordinated expression of L-myo-inositol 1-phosphate synthase (PcINO1) gene along with PcIMT1 indicates that in P. coarctata, accumulation of pinitol via inositol is a stress-regulated pathway. The presence of pinitol synthesizing protein/gene in a wild halophytic rice is remarkable, although its exact role in salt tolerance of P. coarctata cannot be currently ascertained. The enhanced synthesis of pinitol in Porteresia under stress may be one of the adaptive features employed by the plant in addition to its known salt-exclusion mechanism. DOI: 10.1111/j.1365-3040.2008.01850.x

2008-10-01T00:00:00Z Sengupta, Sonali Majumder, Arun Lahiri http://192.168.1.40:8080/xmlui/handle/123456789/1848 2013-02-07T12:05:56Z 2009-03-01T00:00:00Z

Insight into the salt tolerance factors of a wild halophytic rice, Porteresia coarctata: a physiological and proteomic approach Sengupta, Sonali; Majumder, Arun Lahiri Salinity poses a serious threat to yield performance of cultivated rice in South Asian countries. To understand the mechanism of salt-tolerance of the wild halophytic rice, Porteresia coarctata in contrast to the salt-sensitive domesticated rice Oryza sativa, we have compared P. coarctata with the domesticated O. sativa rice varieties under salinity stress with respect to several physiological parameters and changes in leaf protein expression. P. coarctata showed a better growth performance and biomass under salinity stress. Relative water content was conserved in Porteresia during stress and sodium ion accumulation in leaves was comparatively lesser. Scanning electron microscopy revealed presence of two types of salt hairs on two leaf surfaces, each showing a different behaviour under stress. High salt stress for prolonged period also revealed accumulation of extruded NaCl crystals on leaf surface. Changes induced in leaf proteins were studied by two-dimensional gel electrophoresis and subsequent quantitative image analysis. Out of more than 700 protein spots reproducibly detected and analyzed, 60% spots showed significant changes under salinity. Many proteins showed steady patterns of up- or downregulation in response to salinity stress. Twenty protein spots were analyzed by MALDI-TOF, leading to identification of 16 proteins involved in osmolyte synthesis, photosystem functioning, RubisCO activation, cell wall synthesis and chaperone functions. We hypothesize that some of these proteins confer a physiological advantage on Porteresia under salinity, and suggest a pattern of salt tolerance strategies operative in salt-marsh grasses. In addition, such proteins may turn out to be potential targets for recombinant cloning and introgression in salt-sensitive plants. DOI: 10.1007/s00425-008-0878-y

2009-03-01T00:00:00Z Majumder, Arun Lahiri Chatterjee, Jolly http://192.168.1.40:8080/xmlui/handle/123456789/1383 2012-11-21T08:17:36Z 2010-09-01T00:00:00Z

Salt-induced abnormalities on root tip mitotic cells of Allium cepa: prevention by inositol pretreatment Majumder, Arun Lahiri; Chatterjee, Jolly Salt-induced growth reduction of plants is a well-known phenomenon which poses major problem in crop productivity in places where vast majority of land plants are affected by salt. In this report, studies were carried out to reveal the effect of salt injury on the cell division pattern in roots and the role of myo-inositol in preventing the salt-induced ion disequilibrium on the chromosome and DNA degradation in roots. Present study revealed induction of various chromosomal abnormalities on the root tip mitotic cells of Allium cepa by treatment with different concentrations of NaCl (0-500 mM) for 24 h as also the amelioration of such effect by prior treatment of the roots with different concentration of myo-inositol (0-300 mM). Results showed that a narrow albeit definite range of extracellular myo-inositol (100-150 mM) is effective in preventing internucleosomal fragmentation which is the early response in roots under salt stress. Transgenic tobacco plants overexpressing Oryza (OsINO1) as well as Porteresia (PcINO1) cytosolic l-myo-inositol-1-phosphate synthase coding genes can withstand and retain their chromosomal and DNA integrity in 100 mM NaCl solution and can subsequently prevent DNA fragmentation, caused by intracellular endonuclease activity at this salt concentration. DOI: 10.1007/s00709-010-0170-4

2010-09-01T00:00:00Z Patra, Barunava Ray, Sudipta Richter, Andreas Majumder, Arun Lahiri http://192.168.1.40:8080/xmlui/handle/123456789/1381 2012-11-21T08:17:15Z 2010-09-01T00:00:00Z

Enhanced salt tolerance of transgenic tobacco plants by co-expression of PcINO1 and McIMT1 is accompanied by increased level of myo-inositol and methylated inositol Patra, Barunava; Ray, Sudipta; Richter, Andreas; Majumder, Arun Lahiri Introgression and functional expression of either the PcINO1 (l-myo-inositol 1-phosphate synthase or MIPS coding gene from the wild halophytic rice, Porteresia coarctata) or McIMTI (inositol methyl transferase, IMTI coding gene from common ice plant Mesembryanthemum crystallinum) has earlier been shown to confer salt tolerance to transgenic tobacco plants (Sheveleva et al., Plant Physiol 115:1211-1219, 1997; Majee et al., J Biol Chem 279:28539-28552, 2004). In this communication, we show that transgenic tobacco plants co-expressing PcINO1 and McIMT1 gene either in cytosol or in chloroplasts accumulate higher amount of total inositol (free and methyl inositol) compared to non-transgenic plants. These transgenic plants were more competent in terms of growth potential and photosynthetic activity and were less prone to oxidative stress under salt stress. A positive correlation between the elevated level of total inositol and methylated inositol and the capability of the double transgenic plants to withstand a higher degree of salt stress compared to the plants expressing either PcINO1 or McIMT1 alone is inferred. 10.1007/s00709-010-0163-3

2010-09-01T00:00:00Z