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  • Chashmi, Najmeh Ahmadian  (8)
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  • 1
    Language: English
    In: Plant Science, December 2018, Vol.277, pp.139-144
    Description: One of the main sites of the magnetic fields influence on living cells is the cell cycle. The intensity of this influence however, varies depending on the cell type and the duration of the treatment. Suspension of cultured tobacco cells ( cv. Barley 21) were synchronized via sucrose starvation at their stationary growth phase. The cells were then exposed to 0.2 m T SMF up to 24 h. The progression of different cell cycle phases was monitored through flow cytometry in a time course manner. Expression of cell cycle controlling genes and amounts of certain signaling molecules were measured as well. Exposure to SMF delayed G1.S transition which was accompanied by decrease of cyclin-dependent kinases A (CDK A) and D-type cyclin, but an increase in the adenylyl cyclase (AC), transcription factor E2F, retinoblastoma protein (Rbp), and CDK-inhibitor protein 21 (p21) transcript accumulation. Exposure to SMF also increased the contents of nitric oxide (NO), hydrogen peroxide (H O ), and salicylic acid (SA), compared to the control group. The results suggest a signaling pathway triggered by SMF starting from accumulation of NO and H O followed by downstream events including the increase of cyclic nucleotides and subsequent decrease of both CDKA and CycD.
    Keywords: Cell Cycle Progression ; Magnetic Field ; Nicotiana Tabacum ; Nitric Oxide ; Salicylic Acid ; Botany
    ISSN: 0168-9452
    E-ISSN: 1873-2259
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  • 2
    Language: English
    In: Environmental and Experimental Botany, September 2017, Vol.141, pp.41-49
    Description: The mechanisms through which nitric oxide (NO) can influence plant tolerance to Pb are unknown, but may be based on the accumulation of secondary metabolites such as phenolic compounds and polyamines (PAs). This hypothesis was tested by exposing hydroponically-cultured to Pb alone and in combination with sodium nitroprusside (SNP; NO donor), L-NAME (NO synthase inhibitor) and tungstate (TUN; nitrate reductase inhibitor) for a time course of 72 h. The inhibitors strongly repressed NO generation, verifying that Pb and Pb + SNP-induced NO is probably mediated by nitrite and arginine-dependent pathways. The results show that the Pb-induced inhibition of growth was alleviated through application of NO donor, which decreased Pb accumulation in the plant samples, but deteriorated with the decrease in NO, which indicates a higher level of Pb absorbed. The elevated contents of phenolic acids under Pb and Pb + SNP treatments was reduced by the NOS and NR inhibitors and was significantly associated with phenylalanine ammonia-lyase ( ) gene expression patterns. The arginine decarboxylase ( ) gene in the PAs biosynthesis pathway remained unchanged. Considerable alteration was observed in the conjugated PAs in response to the Pb and Pb + SNP applications when compared with the NR and NOS inhibitors that exhibited an increase in free PAs. The results suggest that Pb-evoked NO promotes homeostasis of metabolic pathways to phenolic acids and conjugated PAs that enhance lignification to strengthen against stress.
    Keywords: Nitric Oxide ; Phenolic Compounds ; Polyamines ; No Synthase ; Nitrate Reductase ; Prosopis Farcta ; Environmental Sciences ; Botany
    ISSN: 0098-8472
    E-ISSN: 1873-7307
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  • 3
    Language: English
    In: Cytotechnology, 2018, Vol.70(2), pp.603-614
    Description: The callus and hairy root cultures of Prosopis farcta were established to develop effective strategies to enhance its valuable and medicinally important flavonoid compounds. For callus induction, the hypocotyl, cotyledon and shoot explants were subjected to different plant hormones, naphthalene acetic acid (NAA), benzylaminopurine (BAP), kinetin and dichlorophenoxyacetic acid (2,4-D). Greater callus induction was obtained from hypocotyl explants on MS medium containing 3.0 mg L −1 NAA + 2.0 mg L −1 BAP. With the addition of 0.5 mg L −1 asparagine to this medium, the maximum callus growth was achieved. Hairy root culture of P. farcta was performed using transformation of different explants with strains of Agrobacterium rhizogenes LBA9404 , A4 , AR15834 . The AR15834 strain was more effective for hairy root induction where it caused hairy root formation on 59% of the infected cotyledon explants. We compared profiles of flavonoids isolated from seedling roots, hairy roots, and callus cultures of P. farcta . The colorimetric analysis showed that the content of total flavonoids of hairy roots was 1.54 and 2.52 times higher than in seedling roots and callus, respectively. The presence of flavonoids was verified by LC/MS in positive ion mode. The results showed that flavonoid composition was different in the roots and callus. Naringenin was the major constituent in callus, whereas resveratrol, quercetin and myricetin were the most abundant compounds found in hairy roots. The main objective of this research was to establish hairy roots in P. farcta to synthesize flavonoids at levels comparable to in vitro-grown roots. The present study also opens up a way to further improve the production of pharmaceutically valuable flavonoids and to produce desired metabolites using the hairy root culture system.
    Keywords: Prosopis farcta ; Hairy root ; Agrobacterium rhizogenes ; Callus culture ; Flavonoids ; HPLC ; LC/MS
    ISSN: 0920-9069
    E-ISSN: 1573-0778
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  • 4
    Language: English
    In: Planta, 2018, Vol.248(5), pp.1289-1306
    Description: To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1007/s00425-018-2973-z Byline: Hannaneh Tashackori (1), Mohsen Sharifi (1), Najmeh Ahmadian Chashmi (2), Mehrdad Behmanesh (3), Naser Safaie (4) Keywords: Elicitation; Gene expression; Hairy root; Lignan; Linum album; Phenylpropanoids Abstract: Main conclusion Elicitation of Linum album hairy roots by Piriformospora indica cell wall induced the target genes and specific metabolites in phenylpropanoid pathway and shifted the amino acid metabolism toward the phenolic compound production. Plants have evolved complex mechanisms to defend themselves against various biotic stresses. One of these responses is the production of metabolites that act as defense compounds. Manipulation of plant cell cultures by biotic elicitors is a useful strategy for improving the production of valuable secondary metabolites. This study focused on hairy root culture of Linum album, an important source for lignans. The effects of cell wall elicitor extracted from Piriformospora indica on phenylpropanoid derivatives were evaluated to identify metabolic traits related to biotic stress tolerance. Significant increases in lignin, lignans lariciresinol, podophyllotoxin, and 6-methoxy podophyllotoxin phenolic acids: cinnamic acid, ferulic acid, and salicylic acid flavonoids: myricetin, kaempferol, and diosmin were observed in response to the fungal elicitor. In addition, the gene expression levels of phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, cinnamoyl-CoA reductase, and pinoresinol--lariciresinol reductase significantly increased after elicitation. The composition of free amino acids was altered under the elicitation. Phenylalanine and tyrosine, as precursors of phenylpropanoid metabolites, were increased, but alanine, serine, and glutamic acid significantly decreased in response to the fungal elicitor, suggesting that the amino acid pathway may be shifted toward biosynthesis of aromatic amino acids and precursors of the phenylpropanoid pathway. These results provided evidence that up-regulation of genes involved in the phenylpropanoid pathway in response to the fungal elicitor resulted in enhanced metabolic responses associated with the protection in L. album. This approach can also be applied to improve lignan production. Author Affiliation: (1) 0000 0001 1781 3962, grid.412266.5, Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, 14115-154, Tehran, Iran (2) 0000 0000 9618 7703, grid.411622.2, Department of Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Iran (3) 0000 0001 1781 3962, grid.412266.5, Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran (4) 0000 0001 1781 3962, grid.412266.5, Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran Article History: Registration Date: 06/08/2018 Received Date: 14/03/2018 Accepted Date: 04/08/2018 Online Date: 14/08/2018
    Keywords: Elicitation ; Gene expression ; Hairy root ; Lignan ; Linum album ; Phenylpropanoids
    ISSN: 0032-0935
    E-ISSN: 1432-2048
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  • 5
    Language: English
    In: Environmental and Experimental Botany, March 2018, Vol.147, pp.13-21
    Description: Plants respond to water deficit by adjusting many biochemical pathways that lead to synthesis of osmotically active metabolites and specific proteins that control scavenging of oxygen radicals and water flux. This study was carried out to elucidate the role of phenylethanoid glycosides (PhGs) as a part of primary and secondary metabolic networks responsive to water stress in . The 65-day-old seedlings of in Hoagland's solution were exposed to polyethylene glycol 6000 (˗0.5 bar) over a time course of 72 h. The observed data indicate that H O content and activities of antioxidant enzymes such as catalase (CAT), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) increased at all exposure times. Acteoside and echinacoside (two important PhGs as osmotic metabolites) were highly accumulated in the roots over the exposure time. A positive correlation was observed between PhGs, phenolic acids and flavonoids contents with phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) activities which peaked at over the treatment time. Furthermore, water stress altered soluble sugars content (glucose, mannose, rhamnose and xylose) and free amino acids (phenylalanine, tyrosine and arginine) accumulation. Our observations corroborate that in , the increase of soluble sugars and free amino acids under osmotic stress not only serve as compatible solute but also with favoring PhGs and other phenolic compounds production can improve water stress tolerance.
    Keywords: Phenolic Compounds ; Phenylethanoid Glycosides ; Scrophularia Striata ; Water Stress ; Environmental Sciences ; Botany
    ISSN: 0098-8472
    E-ISSN: 1873-7307
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  • 6
    Language: English
    In: Plant Physiology and Biochemistry, October 2016, Vol.107, pp.374-384
    Description: Manipulation of cell culture media by elicitors is one of most important strategies to inducing secondary metabolism for the production of valuable metabolites. In this investigation, inducing effect of chitosan on physiological, biochemical, and molecular parameters were investigated in cell suspension cultures of Boiss. The results showed that chitosan concentration and time of elicitation are determinants of the effectiveness of the elicitor. Accumulation of aromatic amino acids (phenylalanine [Phe] and tyrosine [Tyr]), phenylpropanoid compounds (phenolic acids [PAs] and echinacoside [ECH]), hydrogen peroxide (H O ) production, phenylalanine ammonia-lyase (PAL) activity and gene expression, and antioxidant enzymes (superoxide dismutase [SOD], peroxidase [POX], catalase [CAT]) activities were altered by changing the exposure time of elicitation. Results showed that, upon elicitation with chitosan, oxidative events were induced, antioxidant responses of . cells were boosted through enhanced activity of an effective series of scavenging enzymes (SOD, CAT, and POX), and biosynthesis of non-enzymatic antioxidants (ECH and PAs [cinnamic, -coumaric and, caffeic acids]). The increase in amino acid content and PAL activity at early days of exposure to chitosan was related with rises in phenolic compounds. These results provide evidence that chitosan by up-regulation of gene differentially improves the production of phenylpropanoid compounds, which are of medical commercial value with good biotechnological prospects.
    Keywords: Aromatic Amino Acids ; Antioxidant Enzymes ; Chitosan ; Phenylalanine Ammonia-Lyase ; Phenylpropanoid Compounds ; Plant Cell Culture ; Scrophularia Striata Boiss ; Botany ; Chemistry
    ISSN: 0981-9428
    E-ISSN: 1873-2690
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  • 7
    Language: English
    In: Ecotoxicology and Environmental Safety, August 2017, Vol.142, pp.293-302
    Description: Reactive oxygen species (ROS) and nitric oxide (NO) are known in triggering defense functions to detoxify heavy metal stresses. To investigate the relevance of ROS production, Pb treatment (400 µM) alone and in combination with 400 µM sodium ascorbate (Asc: as H O scavenger) were given to hydroponically grown seedlings over a time course of 72 h. Data presented here indicate that, the low extent of H O due to scavenging by ascorbate, together with high level of NO improved Pb+Asc- treated growth. Following the evoked potential of both the signals, significant increases in phenolic acids; caffeic, ferulic and salicylic acid were observed with Pb treatment; which are consistent with observed increase in lignin content and consequently with growth inhibition. In contrast, Pb+Asc treatment induced more flavonoids (quercetin, kaempferol, luteolin), diminished phenolic acids contents and also lignin. Elicited expression rate of phenylalanine ammonia-lyase gene ( ) and also its enzymatic activity verified the induced phenylpropanoid metabolism by Pb and Pb+Asc treatments. In comparison with Pb stress, Asc+Pb application induced the high expression of arginine decarboxylase gene ( ), in polyamines biosynthesis pathway, and conducted the N flow towards polyamines and γ-amino butyric acid (GABA). Examining the impact on enzyme activities, catalase, and guaiacol peroxidase; Pb+Asc reduced activity but this increased ascorbate peroxidase, and aconitase activity. Our observations are consistent with conditions favouring NO production and reduced H O can improve Pb tolerance via wide-ranging effects on a primary metabolic network.
    Keywords: Nitric Oxide ; Hydrogen Peroxide ; Phenylpropanoid Metabolism ; Polyamine ; Prosopis Farcta ; Ecology ; Public Health
    ISSN: 0147-6513
    E-ISSN: 1090-2414
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  • 8
    Language: English
    In: Plant Physiology and Biochemistry, February 2016, Vol.99, pp.11-20
    Description: Lead (Pb) is a hazardous heavy metal present in the environment which elicits oxidative stress in plants. To characterize the physiological and biochemical basis of Pb tolerance, seedlings were exposed to Hoagland's solutions at six different Pb concentrations (0, 80, 160, 320, 400 and 480 μM) for different periods of time. As expected, application of Pb significantly increased hydrogen peroxide (H O ) content. In response, deployed the antioxidative defence mechanisms with significantly higher activities of superoxide dismutase (SOD), enzymes related to H O removal, and also the increases in proline as a solute marker of stress. Increases were observed in nitric oxide (NO) production which could also act in triggering defense functions to detoxify Pb. Enhanced phenylalanine ammonia-lyase (PAL) activity at early days of exposure to Pb was correlated with increases in phenolic compounds. Significant increases in phenolic acids and flavonoids; daidzein, vitexin, ferulic acid and salicylic acid were observed with Pb treatment. Furthermore, the stress effects were followed by changes in free amino acid content and composition. Aspartic acid and glycine content was increased but glutamic acid significantly decreased. It is likely that stress signal transduction by NO and H O mediated defence responses to Pb by coordination of antioxidative system and metabolic pathways of phenylpropanoid and amino acids.
    Keywords: Lead ; Enzymatic Antioxidant ; Nitric Oxide ; Phenylalanine Ammonia-Lyase ; Phenolic Acids ; Amino Acids ; Botany ; Chemistry
    ISSN: 0981-9428
    E-ISSN: 1873-2690
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