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Sudha Nair - One of the best experts on this subject based on the ideXlab platform.
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Vibrio rhizosphaerae sp. nov., a red-pigmented bacterium that antagonizes phytopathogenic bacteria.
International journal of systematic and evolutionary microbiology, 2020Co-Authors: N Ramesh Kumar, Sudha NairAbstract:Two novel red-pigmented Vibrio strains, MSSRF3(T) and MSSRF10, with antibacterial activity against phytopathogens were isolated from the rhizosphere region of mangrove-associated wild rice (Porteresia coarctata Tateoka), in Pichavaram, India. The cells were Gram-negative, facultatively anaerobic and rod-shaped and were motile by means of single polar flagella. The two strains were catalase-positive and oxidase-negative, and were able to grow in 0.1-10 % NaCl (with optimum growth in 2 % NaCl) and at temperatures of 20-42 degrees C (optimum growth at 25-30 degrees C). Both strains produced acid and gas from D-glucose under anaerobic conditions and utilized a wide range of compounds as sole carbon and energy sources. The DNA G+C contents determined were 51.3 mol% for strain MSSRF3(T) and 51.0 mol% for strain MSSRF10. Phylogenetic analysis based on 16S rRNA, rpoA, recA and pyrH gene sequences showed that strains MSSRF3(T) and MSSRF10 belong to the genus Vibrio and are very closely related to Vibrio ruber JCM 11486(T), with which they share 98.3-98.5 % (16S rRNA), 98.3-99.7 % (rpoA), 90.2-99.8 % (recA) and 91.3-99.4 % (pyrH) gene sequence similarities, respectively. Levels of DNA-DNA relatedness were 44 % between strains MSSRF3(T) and MSSRF10, 80 % between strain MSSRF10 and V. ruber JCM 11486(T) and 45 % between strain MSSRF3(T) and V. ruber JCM 11486(T). Strain MSSRF3(T) was phenotypically similar to V. ruber JCM 11486(T). However, the inability to reduce nitrate to nitrite, the ability to grow in 0.1 % NaCl and the presence of caseinase were characteristics that allowed differentiation between V. ruber JCM 11486(T) and strain MSSRF3(T). In addition, strain MSSRF3(T) could be differentiated from strain MSSRF10 and its closest relative V. ruber JCM 11486(T) with respect to its genomic fingerprinting analysis (random amplified polymorphic DNA, GTG5, BOX, PCR-restriction fragment length polymorphism and ribotyping). Therefore, based on phenotypic, genotypic, phylogenetic and DNA-DNA hybridization analyses, strain MSSRF3(T) (=LMG 23790(T)=DSM 18581(T)) should be classified as representing the type strain of a novel species of the genus Vibrio, for which the name Vibrio rhizosphaerae sp. nov. is proposed.
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Altererythrobacter indicus sp. nov., isolated from wild rice (Porteresia coarctata Tateoka).
International journal of systematic and evolutionary microbiology, 2020Co-Authors: N Ramesh Kumar, Sudha Nair, Stefan Langer, Hansjurgen Busse, Peter KampferAbstract:A Gram-negative, rod-shaped, non-spore-forming organism, strain MSSRF26T, was isolated from mangrove-associated wild rice in India. On the basis of 16S rRNA gene sequence similarities, strain MSSRF26T was shown to belong to the Alphaproteobacteria, most closely related to Altererythrobacter luteolus and Altererythrobacter epoxidivorans (96.1 and 95.9 % similarity to the respective type strains). Chemotaxonomic data [major ubiquinones Q-10 (91 %) and Q-9 (9 %); major polyamine spermidine, with putrescine, cadaverine and spermine detected only in trace amounts; major polar lipids phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and sphingoglycolipid; major fatty acid C18 : 1 omega 7c and C(14 : 0) 2-OH as hydroxylated fatty acid] supported the affiliation of MSSRF26T to the genus Altererythrobacter. Fatty acid data and physiological and biochemical tests allowed phenotypic differentiation of the isolate from described Altererythrobacter species. Strain MSSRF26T therefore represents a novel species, for which the name Altererythrobacter indicus sp. nov. is proposed, with the type strain MSSRF26T (=LMG 23789T =DSM 18604T).
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Swaminathania salitolerans gen. nov., sp. nov., a salt-tolerant, nitrogen-fixing and phosphate-solubilizing bacterium from wild rice (Porteresia coarctata Tateoka).
International journal of systematic and evolutionary microbiology, 2020Co-Authors: Paripurnanda Loganathan, Sudha NairAbstract:A novel species, Swaminathania salitolerans gen. nov., sp. nov., was isolated from the rhizosphere, roots and stems of salt-tolerant, mangrove-associated wild rice (Porteresia coarctata Tateoka) using nitrogen-free, semi-solid LGI medium at pH 5.5. Strains were Gram-negative, rod-shaped and motile with peritrichous flagella. The strains grew well in the presence of 0.35% acetic acid, 3% NaCl and 1% KNO3, and produced acid from l-arabinose, d-glucose, glycerol, ethanol, d-mannose, d-galactose and sorbitol. They oxidized ethanol and grew well on mannitol and glutamate agar. The fatty acids 18 : 1omega7c/omega9t/omega12t and 19 : 0cyclo omega8c constituted 30.41 and 11.80% total fatty acids, respectively, whereas 13 : 1 AT 12-13 was found at 0.53%. DNA G+C content was 57.6-59.9 mol% and the major quinone was Q-10. Phylogenetic analysis based on 16S rRNA gene sequences showed that these strains were related to the genera Acidomonas, Asaia, Acetobacter, Gluconacetobacter, Gluconobacter and Kozakia in the Acetobacteraceae. Isolates were able to fix nitrogen and solubilized phosphate in the presence of NaCl. Based on overall analysis of the tests and comparison with the characteristics of members of the Acetobacteraceae, a novel genus and species is proposed for these isolates, Swaminathania salitolerans gen. nov., sp. nov. The type strain is PA51T (=LMG 21291T=MTCC 3852T).
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vibrio plantisponsor sp nov a diazotrophic bacterium isolated from a mangrove associated wild rice Porteresia coarctata tateoka
Systematic and Applied Microbiology, 2011Co-Authors: N Rameshkumar, Sudha Nair, Cathrin Spröer, Elke Lang, Bruno Gomezgil, Dinesh N Kumar, Srinivasan Krishnamurthi, Ana RoqueAbstract:Abstract Two Gram negative, facultatively anaerobic, halophilic, motile, slightly curved rod-shaped bacterial strains MSSRF60 T and MSSRF64 were isolated from the roots of a mangrove-associated wild rice collected in the Pichavaram mangroves, India. These strains possess the key functional nitrogenase gene nifH . Phylogenetic analysis based on the 16S rRNA, recA , gapA , mreB , gyrB and pyrH , gene sequences revealed that strains MSSRF60 T and MSSRF64 belong to the genus Vibrio , and had the highest sequence similarity with the type strains of Vibrio diazotrophicus LMG 7893 T (99.7, 94.8, 98.5, 97.9, 94.0 and 90.7%, respectively), Vibrio areninigrae J74 T (98.2, 87.5, 91.5, 88.9, 86.5 and 84.6% respectively) and Vibrio hispanicus LMG 13240 T (97.8, 87.1, 91.7, 89.8, 84.1 and 81.9%, respectively). The fatty acid composition too confirmed the affiliation of strains MSSRF60 T and MSSRF64 to the genus Vibrio . These strains can be differentiated from the most closely related Vibrio species by several phenotypic traits. The DNA G + C content of strain MSSRF60 T was 41.8 mol%. Based on phenotypic, chemotaxonomic, genotypic (multilocus sequence analysis using five genes and genomic fingerprinting using BOX-PCR) and DNA–DNA hybridization analyses, strains MSSRF60 T and MSSRF64 represent a novel species of the genus Vibrio , for which the name Vibrio plantipsonsor sp. nov. is proposed. The type strain is MSSRF60 T (=DSM 21026 T = LMG 24470 T = CAIM 1392 T ).
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Vibrio mangrovi sp. nov., a diazotrophic bacterium isolated from mangrove‐associated wild rice (Poteresia coarctata Tateoka)
Fems Microbiology Letters, 2010Co-Authors: N Rameshkumar, Cathrin Spröer, Elke Lang, Sudha NairAbstract:The taxonomic status of a nitrogen-fixing bacterium, strain MSSRF38T, isolated from the rhizosphere of mangrove-associated wild rice ( Porteresia coarctata Tateoka), in Pichavaram, India, was studied using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the novel strain MSSRF38T was most closely related to Vibrio ruber DSM 16370T (98.3% gene sequence similarity), Vibrio rhizosphaerae DSM 18581T (98.2% sequence similarity) and
Arun Lahiri Majumder - One of the best experts on this subject based on the ideXlab platform.
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Selective manipulation of the inositol metabolic pathway for induction of salt-tolerance in indica rice variety
Scientific Reports, 2019Co-Authors: Rajeswari Mukherjee, Sonali Sengupta, Abhishek Mukherjee, Sritama Mukherjee, Subhendu Bandyopadhyay, Arun Lahiri MajumderAbstract:: Halophytes are rich sources of salt stress tolerance genes which have often been utilized for introduction of salt-tolerance character in salt-sensitive plants. In the present study, we overexpressed PcINO1 and PcIMT1 gene(s), earlier characterized in this laboratory from wild halophytic rice Porteresia coarctata, into IR64 indica rice either singly or in combination and assessed their role in conferring salt-tolerance. Homozygous T3/T4 transgenic plants revealed that PcINO1 transformed transgenic rice lines exhibit significantly higher tolerance upto 200 mM or higher salt concentration with negligible compromise in their growth or other physiological parameters compared to the untransformed system grown without stress. The PcIMT1-lines or the double transgenic lines (DC1) having PcINO1 and PcIMT1 introgressed together, were less efficient in such respect. Comparison of inositol and/or pinitol pool in three types of transgenic plants suggests that plants whose inositol production remains uninterrupted under stress by the functional PcINO1 protein, showed normal growth as in the wild-type plants without stress. It is conceivable that inositol itself acts as a stress-ameliorator and/or as a switch for a number of other pathways important for imparting salt-tolerance. Such selective manipulation of the inositol metabolic pathway may be one of the ways to combat salt stress in plants.
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Functional characterization of two myo-inositol-1-phosphate synthase (MIPS) gene promoters from the halophytic wild rice (Porteresia coarctata)
Planta, 2018Co-Authors: Papri Basak, Sonali Sengupta, Shiny Sangma, Abhishek Mukherjee, Tanushree Agarwal, Arun Lahiri MajumderAbstract:Main conclusion The promoter deletion mutants from second isoform of INO1 (gene-encoding MIPS) from Porteresia coarctata of 932 bp (pPcINO1.2.932) and 793 bp (pPcINO1.2.793) prove to be very efficient as salt/drought stress-inducible promoters, while pPcINO1.2.932 is found to be responsive to cold stress as well. The promoters of the two identified myo -inositol-1-phosphate synthase ( INO1 ) isoforms from salt-tolerant wild rice, Porteresia coarctata ( PcINO1.1 and PcINO1.2 ) have been compared bioinformatically with their counterparts present in the salt-sensitive rice, Oryza sativa . PcINO1.2 promoter was found to be enriched with many abiotic stress-responsive elements, like abscisic acid-responsive elements, MYC-responsive elements, MYB-binding sites, low-temperature stress-responsive elements, and heat-shock elements similar to the ones found in the conserved motifs of the promoters of salt/drought stress-inducible INO1 promoters across Kingdom Planta. To have detailed analysis on the arrangement of cis -acting regulatory elements present in PcINO1 promoters, 5′ deletion mutational studies were performed in dicot model plants. Both transient as well as stable transformation methods were used to check the influence of PcINO1 promoter deletion mutants under salt and physiologically drought conditions using β-glucuronidase as the reporter gene. The deletion mutant from the promoter of PcINO1.2 of length 932 bp (pPcINO1.2.932) was found to be significantly upregulated under drought stress and also in cold stress, while another deletion mutant, pPcINO1.2.793 (of 793 bp), was significantly upregulated under salt stress. P. coarctata being a halophytic species, the high inducibility of pPcINO1.2.932 upon exposure to low-temperature stress was an unexpected result.
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Salt-induced abnormalities on root tip mitotic cells of Allium cepa: prevention by inositol pretreatment
Protoplasma, 2010Co-Authors: Jolly Chatterjee, Arun Lahiri MajumderAbstract: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.
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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.
Protoplasma, 2010Co-Authors: Barunava Patra, Andreas Richter, Arun Lahiri MajumderAbstract: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.
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Porteresia coarctata roxb tateoka a wild rice a potential model for studying salt stress biology in rice
Plant Cell and Environment, 2010Co-Authors: Sonali Sengupta, Arun Lahiri MajumderAbstract:Porteresia coarctata (Syn = Oryza coarctata) is a tetraploid wild rice growing abundantly in the coastal region of India and some other Asian countries. The salt tolerance property of this mangrove associate has been dealt with by a number of workers earlier. The distinct morphology and leaf architecture enabling the plant to exclude salt is a characteristic feature of Porteresia in comparison with Oryza sp. A number of genes have been isolated and characterized from Porteresia that are related to the salt-tolerance property of the plant. Evidence have accumulated that some pathways critical to salt tolerance are in operation in Porteresia of which the inositol metabolic pathway has been recently elaborated. Some of the enzymes of Porteresia have been shown to function as salt-tolerant under in vitro studies giving a clue that this wild halophytic rice may have evolved genes and proteins capable of functioning under a salt environment. Bioprospecting of such genes and proteins coupled with genomic and proteomic approaches remain an exciting area of research in evaluating this plant as a model for salt tolerance for the rice plant.
Sonali Sengupta - One of the best experts on this subject based on the ideXlab platform.
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Selective manipulation of the inositol metabolic pathway for induction of salt-tolerance in indica rice variety
Scientific Reports, 2019Co-Authors: Rajeswari Mukherjee, Sonali Sengupta, Abhishek Mukherjee, Sritama Mukherjee, Subhendu Bandyopadhyay, Arun Lahiri MajumderAbstract:: Halophytes are rich sources of salt stress tolerance genes which have often been utilized for introduction of salt-tolerance character in salt-sensitive plants. In the present study, we overexpressed PcINO1 and PcIMT1 gene(s), earlier characterized in this laboratory from wild halophytic rice Porteresia coarctata, into IR64 indica rice either singly or in combination and assessed their role in conferring salt-tolerance. Homozygous T3/T4 transgenic plants revealed that PcINO1 transformed transgenic rice lines exhibit significantly higher tolerance upto 200 mM or higher salt concentration with negligible compromise in their growth or other physiological parameters compared to the untransformed system grown without stress. The PcIMT1-lines or the double transgenic lines (DC1) having PcINO1 and PcIMT1 introgressed together, were less efficient in such respect. Comparison of inositol and/or pinitol pool in three types of transgenic plants suggests that plants whose inositol production remains uninterrupted under stress by the functional PcINO1 protein, showed normal growth as in the wild-type plants without stress. It is conceivable that inositol itself acts as a stress-ameliorator and/or as a switch for a number of other pathways important for imparting salt-tolerance. Such selective manipulation of the inositol metabolic pathway may be one of the ways to combat salt stress in plants.
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Functional characterization of two myo-inositol-1-phosphate synthase (MIPS) gene promoters from the halophytic wild rice (Porteresia coarctata)
Planta, 2018Co-Authors: Papri Basak, Sonali Sengupta, Shiny Sangma, Abhishek Mukherjee, Tanushree Agarwal, Arun Lahiri MajumderAbstract:Main conclusion The promoter deletion mutants from second isoform of INO1 (gene-encoding MIPS) from Porteresia coarctata of 932 bp (pPcINO1.2.932) and 793 bp (pPcINO1.2.793) prove to be very efficient as salt/drought stress-inducible promoters, while pPcINO1.2.932 is found to be responsive to cold stress as well. The promoters of the two identified myo -inositol-1-phosphate synthase ( INO1 ) isoforms from salt-tolerant wild rice, Porteresia coarctata ( PcINO1.1 and PcINO1.2 ) have been compared bioinformatically with their counterparts present in the salt-sensitive rice, Oryza sativa . PcINO1.2 promoter was found to be enriched with many abiotic stress-responsive elements, like abscisic acid-responsive elements, MYC-responsive elements, MYB-binding sites, low-temperature stress-responsive elements, and heat-shock elements similar to the ones found in the conserved motifs of the promoters of salt/drought stress-inducible INO1 promoters across Kingdom Planta. To have detailed analysis on the arrangement of cis -acting regulatory elements present in PcINO1 promoters, 5′ deletion mutational studies were performed in dicot model plants. Both transient as well as stable transformation methods were used to check the influence of PcINO1 promoter deletion mutants under salt and physiologically drought conditions using β-glucuronidase as the reporter gene. The deletion mutant from the promoter of PcINO1.2 of length 932 bp (pPcINO1.2.932) was found to be significantly upregulated under drought stress and also in cold stress, while another deletion mutant, pPcINO1.2.793 (of 793 bp), was significantly upregulated under salt stress. P. coarctata being a halophytic species, the high inducibility of pPcINO1.2.932 upon exposure to low-temperature stress was an unexpected result.
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the possible overlap between salinity and mechanical challenges in Porteresia coarctata
Proceedings of the Indian National Science Academy, 2014Co-Authors: Sonali SenguptaAbstract:In nature, certain abiotic stresses constitutively acting on plants often go unrecognized. Mechanical stress is one of such stresses, which is manifested on a plant as low-spectrum pressure on the cell membrane due to wind, soil hindrance, gravity or wave current. Although all plants face constant threats from mechanical stress, some ecosystems are more prone to receive such stress. Mangrove vegetation is daily inundated by saline tidal waves that pose a serious threat to the soil binding force of forest undergrowth. Porteresia coarctata is a mangrove rice, which being wild, is avaluable germplasm for bioprospecting of genes and proteins that may confer salt-tolerance to domestic rice. However, P. coarctata is important from ecological point of view as its salt and mechanical stress tolerance is an integral part of the mangrove ecosystem. It is not possible to understand the basic biology of P. coarctata without an ecological perspective. The subterranean part of Porteresia provides a high anchorage and binds soil, thus stabilizing the mangrove vegetation. The root system architecture of Porteresia is unique, with a rhizome and rhizoid-like rootlets. The root system interacts with both salinity and mechanical threat directly, and thus it is important to understand the molecular ecophysiology of Porteresia root and rhizomes to understand the nature of overlap between salinity and mechanical stress in a mangrove ecosystem, which is still elusive.
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Targeted expression of L-myo- inositol 1-phosphate synthase from Porteresia coarctata (Roxb.) Tateoka confers multiple stress tolerance in transgenic crop plants
Journal of Plant Biochemistry and Biotechnology, 2014Co-Authors: Lily Goswami, Sonali Sengupta, Sritama Mukherjee, Rajeswari Mukherjee, Arun Lahiri MajumderAbstract:Improving crop tolerance to osmotic stresses is a longstanding goal of agricultural biotechnology. In the present work the PcINO1 gene coding for a salt-tolerant L- myo -inositol-1-phosphate synthase (MIPS) from Porteresia coarctata (Roxb.) Tateoka, a halophytic wild rice was introgressed into cultivated mustard, Brassica juncea var B85. The transgenic plants demonstrate increased tolerance to salinity and oxidative stress with elevated level of inositol in both roots and shoots. The yield and crop quality of transgenic Brassica plants remain uncompromised and the plants were able to stably grow, set seeds and germinate in saline environments. When targeted to seeds of Nicotiana, PcINO1 was able to improve the seed survival rate under salinity and dehydration. Inositol and its derivatives regulate stress responses in various ways, serving as compatible solutes or signaling molecules. It is implicated that engineering inositol metabolism may affect the plant metabolic network leading to a stress tolerant phenotype as enumerated here in transgenic crop plants. How inositol itself or its derivatives affect the overall metabolic pathways leading to a stress-tolerant phenotype remains an intriguing question for future investigations.
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Cloning, characterization and expression of a chloroplastic fructose-1,6-bisphosphatase from Porteresia coarctata conferring salt-tolerance in transgenic tobacco
Plant Cell Tissue and Organ Culture (PCTOC), 2013Co-Authors: Jolly Chatterjee, Barunava Patra, Susmita Maitra, Papri Basak, Sritama Mukherjee, Rajeswari Mukherjee, Shilpi Ghosh, Sanghamitra Bhattacharyya, Krishnarup Ghoshdastidar, Sonali SenguptaAbstract:A gene coding for the chloroplastic fructose 1,6-bisphosphatase ( PcCFR ) in Porteresia coarctata Tateoka (Roxb.), a halophytic wild rice, has been isolated along with its rice ( Oryza sativa ; var. indica ) homologue ( OsCFR ), cloned and sequenced. Comparison between the nucleotide and deduced amino acid sequences of these two revealed a difference in five amino acid residues, namely Glu^14, Thr^24, Ala^48, Ala^163 and Arg^296 in OsCFR which have been found to be replaced by Ser^14, Ile^24, Ser^48, Ser^163 and Lys^296 in PcCFR respectively. The purified recombinant PcCFR is found to retain its enzymatic activity in presence of up to 500 mM NaCl in vitro as opposed to OsCFR, which is inactivated even at lower salt concentration. The six in vitro point mutant proteins of PcCFR showed varied degree of sensitivity towards high salt, with the maximum OsCFR-like effect in the triple mutant S^14A-S^48A-S^163A suggesting a possible concerted role of all three serine residues in the in vitro salt tolerance property of PcCFR protein. Transgenic tobacco plants with chloroplast targeted PcCFR and OsCFR gene(s) have been developed under constitutive expression of CaMV 35S promoter and NOS terminator. The PcCFR transgenics showed better plant growth during exposure to salt stress in comparison to either the OsCFR or the empty vector transformed plants. The PcCFR transgenics also revealed enhanced photosynthetic efficiency coupled with protection to both photodamage of PSII and chlorophyll degradation through better reactive oxygen species scavenging at higher concentration of NaCl during late salt-stress growth.
Ajay Parida - One of the best experts on this subject based on the ideXlab platform.
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Salt stress effects on the accumulation of vacuolar H + -ATPase subunit c transcripts in wild rice, Porteresia coarctata (Roxb.) Tateoka
Current Science, 2020Co-Authors: P Senthilkumar, M N Jithesh, Madasamy Parani, S Rajalakshmi, K Praseetha, Ajay ParidaAbstract:The ion pump, vacuolar H + -ATPase (V-ATPase) plays a major role in the maintenance of cellular pH, and influences the transport of cations into the vacuoles of plant cells. A cDNA clone (PcVHA-cl) encoding the c subunit of V-ATPase was isolated from the salt-tolerant wild rice, Porteresia coarctata. The DNA sequence of PcVHA-cl showed significant homology with V-ATPase subunit c of rice. The deduced amino acid sequence of PcVHA-cl and other reported c subunits were compared, and sequence relationships have been drawn to know their genetic relatedness. Southern analysis suggested the presence of multiple coding regions for subunit c in P. coarctata. Northern and Western analyses of salt-treated P. coarctata plants revealed that subunit c of V-ATPase is upregulated by NaCl treatment at both transcriptional and translational level.
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expression of wild rice Porteresia coarctata pcnhx1 antiporter gene pcnhx1 in tobacco controlled by pcnhx1 promoter pcnhx1p confers na specific hypocotyl elongation and stem specific na accumulation in transgenic tobacco
Plant Physiology and Biochemistry, 2019Co-Authors: Vidya Jegadeeson, Ajay Parida, Kumkum Kumari, Shalini Pulipati, Gayatri VenkataramanAbstract:Abstract Soil salinization is a major abiotic stress condition that affects about half of global agricultural lands. Salinity leads to osmotic shock, ionic imbalance and/or toxicity and build-up of reactive oxygen species. Na⁺/H⁺ antiporters (NHXs) are integral membrane transporters that catalyze the electro-neutral exchange of K⁺/Na⁺ for H⁺ and are implicated in cell expansion, development, pH/ion homeostasis and salt tolerance. Porteresia coarctata is a salt secreting halophytic wild rice that thrives in the coastal-riverine interface. P. coarctata NHX1 (PcNHXI) expression is induced by salinity in P. coarctata roots and shows high sequence identity to Oryza sativa NHX1. PcNHX1 confers hygromycin and Li+ sensitivity and Na+ tolerance transport in a yeast strain lacking sodium transport systems. Additionally, transgenic PcNHX1 expressing tobacco seedlings (PcNHX1 promoter) show significant growth advantage under increasing concentrations of NaCl and MS salts. Etiolated PcNHX1 seedlings also exhibit significantly elongated hypocotyl lengths in 100 mM NaCl. PcNHX1 expression in transgenic tobacco roots increases under salinity, similar to expression in P. coarctata roots. Under incremental salinity, transgenic lines show reduction in leaf Na+, stem specific accumulation of Na+ and K+ (unaltered Na+/K+ ratios). PcNHX1 transgenic plants also show enhanced chlorophyll content and reduced malondialdehyde (MDA) production in leaves under salinity. The above data suggests that PcNHX1 overexpression (controlled by PcNHX1p) enhances stem specific accumulation of Na+, thereby protecting leaf tissues from salt induced injury.
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long term exposure to combined treatment of elevated co 2 and salt induces iron deficiency responses in Porteresia coarctata
Current Science, 2017Co-Authors: Deepanwita Purohit, H. M. Sankararamasubramanian, Maganti Sowjanya, Ajay ParidaAbstract:Plants with rising atmospheric carbon dioxide (CO 2 ) level in the environment may change their nutrient demands to sustain growth. The mechanisms concerning iron dynamics in plants under the interactive effect of salinity and elevated CO 2 are poorly understood. This study examines the effects of long-term as well as short-term growth at elevated CO 2 and salt on iron deficiency-associated molecular responses of Porteresia coarctata through analysing the transcript expression of iron deficiency-responsive genes in the leaf tissue. Plants were grown in hydroponic media at ambient or elevated atmospheric CO 2 (500 μl l -1 ), with or without salt, and samples were analysed at three time points, on the 15th, 45th and 90th day. The semiquantitative RT-PCR analysis showed an induced expression of iron deficiency-responsive transcription factor PcIDEF1 and its putative targets OsIRO2-like gene, OsNAAT1-like gene, OsNAS1-like gene, OsYSL2- like gene and PcIRT1 at elevated CO 2 with NaCl. Furthermore, a positive correlation in gene expression was observed between PcIDEF1 and its putative targets in the 15th and 45th day samples. By contrast, in the 90th day sample, correlation in gene expression was less evident. Our findings suggest that the interactive effect of elevated CO 2 and NaCl can induce a set of molecular responses in P. coarctata for enhanced iron uptake and utilization, thereby reflecting an iron deficiency like stress under such conditions.
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A vacuolar antiporter is differentially regulated in leaves and roots of the halophytic wild rice Porteresia coarctata (Roxb.) Tateoka
Molecular Biology Reports, 2015Co-Authors: Praseetha Kizhakkedath, Vidya Jegadeeson, Gayatri Venkataraman, Ajay ParidaAbstract:Vacuolar NHX-type antiporters play a role in Na^+/K^+ uptake that contributes to growth, nutrition and development. Under salt/osmotic stress they mediate the vacuolar compartmentalization of K^+/Na^+, thereby preventing toxic Na^+K^+ ratios in the cytosol. Porteresia coarctata (Roxb.) Tateoka, a mangrove associate, is a distant wild relative of cultivated rice and is saline as well as submergence tolerant. A vacuolar NHX homolog isolated from a P. coarctata cDNA library ( PcNHX1 ) shows 96 % identity (nucleotide level) to OsNHX1 . Diurnal PcNHX1 expression in leaves was found to be largely unaltered, though damped by salinity. PcNHX1 promoter directed GUS expression is phloem-specific in leaves, stem and roots of transgenic plants in the absence of stress. Under NaCl stress, GUS expression was also seen in the epidermal and sub-epidermal layers (mesophyll, guard cells and trichomes) of leaves, root tip. The salinity in the rhizosphere of P. coarctata varies considerably due to diurnal/semi-diurnal tidal inundation. The diurnal expression of PcNHX1 in leaves and salinity induced expression in roots may have evolved in response to dynamic changes in salinity of in the P. coarctata rhizosphere. Despite high sequence conservation between OsNHX1 and PcNHX1 , the distinctive expression pattern of PcNHX1 exemplifies how variation in expression is fine tuned to suit the halophytic growth habitat of a plant.
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characterization of a type 3 metallothionein isolated from Porteresia coarctata
Biologia Plantarum, 2011Co-Authors: Balasundaram Usha, N S Keeran, M Harikrishnan, K Kavitha, Ajay ParidaAbstract:Metallothioneins are involved in detoxification of heavy metals. A cDNA encoding type 3 metallothionein (PcMT3) was isolated from the salt stressed leaf cDNA library of Porteresia coarctata (Roxb.) Tateoka (wild rice) that grows well in the heavy metal laden estuarine soils. The PcMT3 cDNA (581 bp) encodes a protein of 64 amino acids. PcMT3 is highly homologous (82 %) to OsMT-I-3a of rice, but is unique from other type 3 plant MTs due to the presence of an additional glycine residue in the C-terminal domain. Analysis of the 5′ upstream region of PcMT3 showed the presence of cis-acting elements like the CG box and STRE previously reported to be involved in gene expression under heavy metal stress. Southern analysis suggested the presence of more than one copy of PcMT3-like sequences in the P. coarctata genome. Analysis of genomic clone of PcMT3 revealed the presence of two introns. A comparison of the genomic sequence of PcMT3 with closely similar type 3 MTs from rice and mangrove species revealed conservation in the number and position of introns. Transcript profiling for PcMT3 in P. coarctata leaves in the presence of Cd, Cu and Zn showed an increase in transcript accumulation.
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vibrio plantisponsor sp nov a diazotrophic bacterium isolated from a mangrove associated wild rice Porteresia coarctata tateoka
Systematic and Applied Microbiology, 2011Co-Authors: N Rameshkumar, Sudha Nair, Cathrin Spröer, Elke Lang, Bruno Gomezgil, Dinesh N Kumar, Srinivasan Krishnamurthi, Ana RoqueAbstract:Abstract Two Gram negative, facultatively anaerobic, halophilic, motile, slightly curved rod-shaped bacterial strains MSSRF60 T and MSSRF64 were isolated from the roots of a mangrove-associated wild rice collected in the Pichavaram mangroves, India. These strains possess the key functional nitrogenase gene nifH . Phylogenetic analysis based on the 16S rRNA, recA , gapA , mreB , gyrB and pyrH , gene sequences revealed that strains MSSRF60 T and MSSRF64 belong to the genus Vibrio , and had the highest sequence similarity with the type strains of Vibrio diazotrophicus LMG 7893 T (99.7, 94.8, 98.5, 97.9, 94.0 and 90.7%, respectively), Vibrio areninigrae J74 T (98.2, 87.5, 91.5, 88.9, 86.5 and 84.6% respectively) and Vibrio hispanicus LMG 13240 T (97.8, 87.1, 91.7, 89.8, 84.1 and 81.9%, respectively). The fatty acid composition too confirmed the affiliation of strains MSSRF60 T and MSSRF64 to the genus Vibrio . These strains can be differentiated from the most closely related Vibrio species by several phenotypic traits. The DNA G + C content of strain MSSRF60 T was 41.8 mol%. Based on phenotypic, chemotaxonomic, genotypic (multilocus sequence analysis using five genes and genomic fingerprinting using BOX-PCR) and DNA–DNA hybridization analyses, strains MSSRF60 T and MSSRF64 represent a novel species of the genus Vibrio , for which the name Vibrio plantipsonsor sp. nov. is proposed. The type strain is MSSRF60 T (=DSM 21026 T = LMG 24470 T = CAIM 1392 T ).
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Vibrio mangrovi sp. nov., a diazotrophic bacterium isolated from mangrove‐associated wild rice (Poteresia coarctata Tateoka)
Fems Microbiology Letters, 2010Co-Authors: N Rameshkumar, Cathrin Spröer, Elke Lang, Sudha NairAbstract:The taxonomic status of a nitrogen-fixing bacterium, strain MSSRF38T, isolated from the rhizosphere of mangrove-associated wild rice ( Porteresia coarctata Tateoka), in Pichavaram, India, was studied using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the novel strain MSSRF38T was most closely related to Vibrio ruber DSM 16370T (98.3% gene sequence similarity), Vibrio rhizosphaerae DSM 18581T (98.2% sequence similarity) and
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mangrovibacter plantisponsor gen nov sp nov a nitrogen fixing bacterium isolated from a mangrove associated wild rice Porteresia coarctata tateoka
International Journal of Systematic and Evolutionary Microbiology, 2010Co-Authors: N Rameshkumar, Elke Lang, Sudha NairAbstract:A facultatively anaerobic, nitrogen-fixing bacterium, strain MSSRF40T, was isolated from roots of mangrove-associated wild rice (Porteresia coarctata Tateoka). On the basis of 16S rRNA gene sequence similarities, strain MSSRF40T was shown to belong to the family Enterobacteriaceae, most closely related to Cronobacter muytjensii E603T (97.2 % sequence similarity), Enterobacter cloacae subsp. dissolvens LMG 2683T (97.1 %), E. radicincitans D5/23T (97.1 %) and E. ludwigii EN-119T (97.0 %). Sequence analysis of rpoB, gyrB and hsp60 genes showed that strain MSSRF40T had relatively low sequence similarity (<91, <84 and <90 %) to recognized species of different genera of the family Enterobacteriaceae and formed an independent phyletic lineage in all phylogenetic analyses using the 16S rRNA, rpoB, gyrB and hsp60 genes, clearly indicating that strain MSSRF40T could not be affiliated to any of the recognized genera within the family Enterobacteriaceae. The dominant cellular fatty acids were C16 : 0, C16 : 1 ω7c and/or iso-C15 : 0 2-OH and C18 : 1 ω7c, similar to those of other members of the Enterobacteriaceae. The DNA G+C content was 50.1 mol%. Phylogenetic distinctiveness and phenotypic differences from its phylogenetic neighbours indicated that strain MSSRF40T represents a novel species and genus within the family Enterobacteriaceae, for which the name Mangrovibacter plantisponsor gen. nov., sp. nov. is proposed. The type strain of Mangrovibacter plantisponsor is strain MSSRF40T (=LMG 24236T =DSM 19579T).
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Mangrovibacter plantisponsor gen. nov., sp. nov., a nitrogen-fixing bacterium isolated from a mangrove-associated wild rice (Porteresia coarctata Tateoka).
International journal of systematic and evolutionary microbiology, 2009Co-Authors: N Rameshkumar, Elke Lang, Sudha NairAbstract:A facultatively anaerobic, nitrogen-fixing bacterium, strain MSSRF40(T), was isolated from roots of mangrove-associated wild rice (Porteresia coarctata Tateoka). On the basis of 16S rRNA gene sequence similarities, strain MSSRF40(T) was shown to belong to the family Enterobacteriaceae, most closely related to Cronobacter muytjensii E603(T) (97.2 % sequence similarity), Enterobacter cloacae subsp. dissolvens LMG 2683(T) (97.1 %), E. radicincitans D5/23(T) (97.1 %) and E. ludwigii EN-119(T) (97.0 %). Sequence analysis of rpoB, gyrB and hsp60 genes showed that strain MSSRF40(T) had relatively low sequence similarity (
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vibrio Porteresiae sp nov a diazotrophic bacterium isolated from a mangrove associated wild rice Porteresia coarctata tateoka
International Journal of Systematic and Evolutionary Microbiology, 2008Co-Authors: N Rameshkumar, Youhei Fukui, Tomoo Sawabe, Sudha NairAbstract:Two facultatively anaerobic, nitrogen-fixing bacteria (strains MSSRF30T and MSSRF31) were isolated from a mangrove-associated wild rice (Porteresia coarctata Tateoka). These strains were determined to be nitrogen-fixers using the acetylene reduction assay and by PCR detection of a nifH gene amplicon. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the novel strains were most closely related to Vibrio fluvialis LMG 7894T (96.8 % gene sequence similarity), Vibrio furnissii LMG 7910T (96.8 % sequence similarity) and Vibrio tubiashii CIP 102760T (96.7 % sequence similarity). Further multilocus sequence analysis using recA, pyrH, rpoA and nifH genes also showed low levels of sequence similarities (83–93 %) with all species of the genus Vibrio with validly published names. A multigene phylogenetic tree using concatenated sequences of the four genes (16S rRNA, rpoA, recA and pyrH) showed that strains MSSRF30T and MSSRF31 occupied a distinct phylogenetic position, forming a long branching that was not clustered with any other recognized Vibrio species. The fatty acid profile also suggested that the novel strains belonged to the genus Vibrio. The results of physiological and biochemical tests, genomic fingerprinting and DNA–DNA hybridization analyses clearly differentiated both novel strains from their closest phylogenetic neighbours, Vibrio cholerae IID6019, Vibrio mimicus LMG 7896T, V. fluvialis LMG 7894T and V. furnissii LMG 7910T. Several phenotypic traits enabled the differentiation of strain MSSRF30T from other species of the genus Vibrio. The DNA G+C content of strain MSSRF30T was 44.4±3.1 mol%. Based on genotypic, phenotypic, chemotaxonomic, phylogenetic and DNA–DNA hybridization analyses, the name Vibrio Porteresiae sp. nov. (type strain MSSRF30T=LMG 24061T=DSM 19223T) is proposed for this novel taxon.