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1.
BMC Plant Biol ; 19(1): 274, 2019 Jun 24.
Article in English | MEDLINE | ID: mdl-31234787

ABSTRACT

BACKGROUND: miRNAs are major regulators of gene expression and have proven their role in understanding the genetic regulation of biosynthetic pathways. Stevioside and rebaudioside-A, the two most abundant and sweetest compounds found in leaf extract of Stevia rebaudiana, have been used for many years in treatment of diabetes. It has been found that the crude extract is more potent than the purified extract. Stevioside, being accumulated in higher concentration, imparts licorice like aftertaste. Thus, in order to make the sweetener more potent and palatable, there is a need to increase the intrinsic concentration of steviol glycosides and to alter the ratio of rebaudioside-A to stevioside. Doing so would significantly increase the quality of the sweeteners, and the potential to be used on a wider scale. To do so, in previous report, miRNAs associated with genes of steviol glycosides biosynthetic pathway were identified in S. rebaudiana. In continuation to that in this study, the two miRNAs (miR319g and miRStv_11) targeting key genes of steviol glycosides biosynthetic pathway were modulated and their impact was evaluated on steviol glycosides contents. RESULTS: The over-expression results showed that miRStv_11 induced, while miR319g had repressive action on its target genes. The knock-down constructs for miR319g and miRStv_11 were then prepared and it was demonstrated that the expression of anti-miR319g produced inhibitory effect on its target miRNA, resulting in enhanced expression of its target genes. On the other hand, anti-miRStv_11 resulted in down-regulation of miRStv_11 and its target gene. Further miRStv_11 and anti-miR319gwere co-expressed which resulted in significant increase in stevioside (24.5%) and rebaudioside-A (51%) contents. CONCLUSION: In conclusion, the role of miR319g and miRStv_11 was successfully validated in steviol gycosides biosynthetic pathway gene regulation and their effect on steviol gycosides contents. In this study, we found the positively correlated miRNA-mRNA interaction network in plants, where miRStv_11 enhanced the expression of KAH gene. miRNAs knock-down was also successfully achieved using antisense precursors. Overall, this study thus reveals more complex nature and fundamental importance of miRNAs in biosynthetic pathway related gene networks and hence, these miRNAs can be successfully employed to enhance the ratio of rebaudioside-A to stevioside, thus enhancing the sweetening indices of this plant and making it more palatable.


Subject(s)
Diterpenes, Kaurane/biosynthesis , Glucosides/biosynthesis , MicroRNAs/metabolism , RNA, Plant/metabolism , Stevia/metabolism , Diterpenes, Kaurane/chemistry , Diterpenes, Kaurane/genetics , Gene Expression Regulation, Plant , Gene Knockout Techniques , Gene Silencing , Glucosides/chemistry , Glucosides/genetics , MicroRNAs/genetics , Plant Leaves/chemistry , Promoter Regions, Genetic , RNA, Plant/genetics , Stevia/genetics , Sweetening Agents/chemistry
2.
J Virol ; 91(6)2017 03 15.
Article in English | MEDLINE | ID: mdl-28053106

ABSTRACT

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is the leading cause of viral encephalitis in Southeast Asia with potential to become a global pathogen. Here, we identify glucose-regulated protein 78 (GRP78) as an important host protein for virus entry and replication. Using the plasma membrane fractions from mouse neuronal (Neuro2a) cells, mass spectroscopy analysis identified GRP78 as a protein interacting with recombinant JEV envelope protein domain III. GRP78 was found to be expressed on the plasma membranes of Neuro2a cells, mouse primary neurons, and human epithelial Huh-7 cells. Antibodies against GRP78 significantly inhibited JEV entry in all three cell types, suggesting an important role of the protein in virus entry. Depletion of GRP78 by small interfering RNA (siRNA) significantly blocked JEV entry into Neuro2a cells, further supporting its role in virus uptake. Immunofluorescence studies showed extensive colocalization of GRP78 with JEV envelope protein in virus-infected cells. This interaction was also confirmed by immunoprecipitation studies. Additionally, GRP78 was shown to have an important role in JEV replication, as treatment of cells post-virus entry with subtilase cytotoxin that specifically cleaved GRP78 led to a substantial reduction in viral RNA replication and protein synthesis, resulting in significantly reduced extracellular virus titers. Our results indicate that GRP78, an endoplasmic reticulum chaperon of the HSP70 family, is a novel host factor involved at multiple steps of the JEV life cycle and could be a potential therapeutic target.IMPORTANCE Recent years have seen a rapid spread of mosquito-borne diseases caused by flaviviruses. The flavivirus family includes West Nile, dengue, Japanese encephalitis, and Zika viruses, which are major threats to public health with potential to become global pathogens. JEV is the major cause of viral encephalitis in several parts of Southeast Asia, affecting a predominantly pediatric population with a high mortality rate. This study is focused on identification of crucial host factors that could be targeted to cripple virus infection and ultimately lead to development of effective antivirals. We have identified a cellular protein, GRP78, that plays a dual role in virus entry and virus replication, two crucial steps of the virus life cycle, and thus is a novel host factor that could be a potential therapeutic target.


Subject(s)
Encephalitis Virus, Japanese/physiology , Heat-Shock Proteins/metabolism , Host-Pathogen Interactions , Virus Internalization , Virus Replication , Animals , Cell Line , Endoplasmic Reticulum Chaperone BiP , Humans , Mass Spectrometry , Mice , Microscopy, Confocal , Microscopy, Fluorescence , Neurons/virology , Protein Binding , Viral Envelope Proteins/metabolism
3.
Environ Toxicol ; 30(11): 1285-96, 2015 Nov.
Article in English | MEDLINE | ID: mdl-24771359

ABSTRACT

With the advancement of human race, different anthropogenic activities have heaped the environment with chemicals that can cause alteration in the immune system of exposed organism. As a first line of barrier, the evolutionary conserved innate immunity is crucial for the health of an organism. However, there is paucity of information regarding in vivo assessment of the effect of environmental chemicals on innate immunity. Therefore, we examined the effect of a widely used environmental chemical, Cr(VI), on humoral innate immune response using Drosophila melanogaster. The adverse effect of Cr(VI) on host humoral response was characterized by decreased gene expression of antimicrobial peptides (AMPs) in the exposed organism. Concurrently, a significantly decreased transcription of humoral pathway receptors (Toll and PGRP) and triglyceride level along with inhibition of antioxidant enzyme activities were observed in exposed organism. This in turn weakened the immune response of exposed organism that was manifested by their reduced resistance against bacterial infection. In addition, overexpression of the components of humoral immunity particularly Diptericin benefits Drosophila from Cr(VI)-induced humoral immune-suppressive effect. To our knowledge, this is the first report regarding negative impact of an environmental chemical on humoral innate immune response of Drosophila along with subsequent protection by AMPs, which may provide novel insight into host-chemical interactions. Also, our data validate the utility and sensitivity of Drosophila as a model that could be used for screening the possible risk of environmental chemicals on innate immunity with minimum ethical concern that can be further extrapolated to higher organisms.


Subject(s)
Chromium/toxicity , Drosophila melanogaster/drug effects , Environmental Pollutants/toxicity , Immunity, Humoral/drug effects , Immunity, Innate/drug effects , Animals , Antioxidants/metabolism , Chromium/pharmacokinetics , Dose-Response Relationship, Drug , Drosophila melanogaster/genetics , Drosophila melanogaster/immunology , Environmental Pollutants/pharmacokinetics , Gene Expression/drug effects , Humans , Immunity, Humoral/genetics , Immunity, Innate/genetics , Oxidative Stress/drug effects , Oxidative Stress/genetics , Oxidative Stress/immunology , Real-Time Polymerase Chain Reaction , Toxicity Tests
4.
Biochem Biophys Res Commun ; 445(1): 138-44, 2014 Feb 28.
Article in English | MEDLINE | ID: mdl-24491547

ABSTRACT

Morphological transition (yeast-hyphal and white-opaque) is an important biological process in the life cycle of pathogenic yeast, Candida albicans and is a major determinant of virulence. Earlier reports show that the amino sugar, N-acetylglucosamine (GlcNAc) induces white to opaque switching in this pathogen. We report here a new contributor to this switching phenomenon, namely N-acetylglucosamine kinase or HXK1, the first enzyme of the GlcNAc catabolic cascade. Microarray profile analysis of wild type vs. hxk1 mutant cells grown under switching inducing condition showed upregulation of opaque specific and cell wall specific genes along genes involved in the oxidative metabolism. Further, our qRT-PCR and immunoblot analysis revealed that the expression levels of Wor1, a master regulator of the white-opaque switching phenomenon remained unaltered during this HXK1 mediated transition. Thus the derepression of opaque specific gene expression observed in hxk1 mutant could be uncoupled to the expression of WOR1. Moreover, this regulation via HXK1 is independent of Ras1, a major regulator of morphogenetic transition and probably independent of MTL locus too. These results extend our understanding of multifarious roles of metabolic enzymes like Hxk1 and suggest an adaptive mechanism during host-pathogen interactions.


Subject(s)
Candida albicans/genetics , Fungal Proteins/genetics , Phosphotransferases (Alcohol Group Acceptor)/genetics , Transcriptome , Candida albicans/enzymology , Candida albicans/physiology , Cell Wall/genetics , Cell Wall/metabolism , Fungal Proteins/metabolism , Gene Expression Regulation, Fungal , Immunoblotting , Mutation , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Up-Regulation
5.
Mol Biol Rep ; 41(9): 5607-25, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24893599

ABSTRACT

Lentil (Lens culinaris Medik.) is an economically important grain legume, yet the genetic and genomic resources remain largely uncharacterized and unexploited in this crop. Microsatellites have become markers of choice for crop improvement applications. Hence, simple sequence repeat (SSR) markers were developed for lentil through the construction of genomic library enriched for GA/CT motifs. As a result 122 functional SSR primer pairs were developed from 151 microsatellite loci and validated in L. culinaris cv. Precoz. Thirty three SSR markers were utilized for the analysis of genetic relationships between cultivated and wild species of Lens and related legumes. A total of 123 alleles were amplified at 33 loci ranging from 2-5 alleles with an average of 3.73 alleles per locus. Polymorphic information content (PIC) for all the loci ranged from 0.13 to 0.99 with an average of 0.66 per locus. Varied levels of cross genera transferability were obtained ranging from 69.70 % across Pisum sativum to 12.12 % across Vigna radiata. The UPGMA based dendrogram was able to establish the uniqueness of each genotype and grouped them into two major clusters clearly resolving the genetic relationships within lentil and related species. The new set of SSR markers reported here were efficient and highly polymorphic and would add to the existing repertoire of lentil SSR markers to be utilized in molecular breeding. Moreover, the improved knowledge about intra- and inter-specific genetic relationships would facilitate germplasm utilization for lentil improvement.


Subject(s)
Genetic Variation , Genome, Plant , Lens Plant/classification , Lens Plant/genetics , Microsatellite Repeats , Alleles , DNA Primers , DNA, Plant/genetics , Genetic Loci , Genomic Library , Genomics , Multigene Family , Polymorphism, Genetic , Sequence Analysis, DNA , Species Specificity
6.
Plant Sci ; 346: 112167, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38925476

ABSTRACT

The secondary plant metabolites are of enormous importance because of their extensive medicinal, nutraceutical, and industrial applications. In plants, these secondary metabolites are often found in extremely small amounts, therefore, following the discovery of any prospective metabolite, the main constraining element is the ability to generate enough material for use in both industrial and therapeutic settings. In order to satisfy the rising demand for value-added metabolites, researchers prefer to use different molecular approaches for scalable and sustainable production of these phytocompounds. Here, we discuss the emerging regulatory trends in engineering these bioactive-phytocompounds and provide recommendation on successful employment of these state-of-the-art technologies for translation of these academic researches into novel process and products.

7.
3 Biotech ; 12(11): 311, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36276443

ABSTRACT

MicroRNAs play a central role in gene regulation and emerge as novel targets for secondary metabolites improvement in plants. The crops thus can be improved through knowledge obtained by the study of miRNAs because of their conserved nature in gene regulation. The present study has been carried out on Tinospora cordifolia (T. cordifolia), because of its illimitable application for the treatment of various diseases. This plant has tremendous medicinal properties, yet unexplored at the molecular level, and has not received much recognition in the scientific field. Thus, here computational analysis was performed to identify T. cordifolia miRNAs using EST database. Using these miRNAs, we predicted their targets which were found to be associated with the regulation of diverse gene networks including 433 berberine biosynthesis genes in T. cordifolia. Further, selected miRNAs were validated and their expression was detected in different T. cordifolia tissues followed by expression analysis of their target mRNAs. These data were then compared with the metabolic profile of T. cordifolia with an emphasis on therapeutically important compound berberine. In this study, we did simultaneous miRNA/target gene expression and metabolome analysis which opens a new way for initiating new proposition and prioritization of miRNAs/genes/metabolites for targeted follow­up metabolic engineering experimentations. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03342-9.

8.
J Appl Genet ; 63(2): 237-263, 2022 May.
Article in English | MEDLINE | ID: mdl-35106708

ABSTRACT

Lagenaria siceraria (Molina) Standley is an important cultivated crop with its immense importance in pharmaceutical industry and as vegetable. Its seed, root, stem, leaves, flower, and fruit are used as an ointment for ailment of various diseases throughout Asia. Despite its worldwide importance, informative co-dominant microsatellite markers in the bottle gourd crop are very restricted, impeding genetic improvement, cultivar identification, and phylogenetic studies. Next-generation sequencing has revolutionized the approaches for discovery, assessment, and validation of molecular markers. We conducted a genome-wide analysis, for developing SSR markers by utilizing restriction site-associated DNA sequencing (RAD-Seq) data obtained from NCBI. By performing in silico mining of microsatellite repeat motifs, we developed 45,066 perfect SSR markers. Of which 207 markers were successfully validated and 120 (57.97%) polymorphic primer pairs were utilized for an in-depth genetic diversity and population structure analysis of 96 accessions from the National Genebank of India. Tetranucleotide repeats (∼34.3%) were the most prevalent followed by trinucleotide repeats (∼30.73%), further 21.03%, 9.6%, and 4.3% of di-, penta-, and hexa-nucleotide repeats in the bottle gourd genome, respectively. Synteny of SSR markers on 11 bottle gourd linkage groups was correlated with the 7 chromosomes of cucumber (93.2%), 12 chromosomes of melon (87.4%), and 11 of watermelon (90.8%). The generated SSR markers provide a valuable tool for germplasm characterization, genetic linkage map construction, studying synteny, gene discovery, and for breeding in bottle gourd and other cucurbits species. KEY MESSAGE: Development of 45,066 perfect microsatellite markers as a valuable tool for marker assisted selection (MAS) in plant breeding.


Subject(s)
Genome, Plant , Plant Breeding , Genetic Variation , Microsatellite Repeats , Phylogeny , Synteny
9.
Biotechnol Rep (Amst) ; 36: e00761, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36159743

ABSTRACT

The therapeutic efficacy of Artemisia annua L. is governed by artemisinin (ART), prevalently produced by A. annua extraction. Due to the modest amount of ART (0.01-1 %dw) in this plant, commercialization of ACTs is difficult. In this study, the floral-dip based transformation protocol for A. annua was developed to enhance expression of artemisinin biosynthesis genes and ART content. For dipping, the effective infiltration media components were optimized, and to obtain high transformation (26.9%) partially open bud stage capitulum of floral development was used. Hygromycin phospho-transferase (hptII) selection marker was used to validate the transformed T1 progenies. The copy numbers of the transgene (hptII) in T1 progenies were determined using a sensitive, high-throughput SYBR Green based quantitative RT-PCR. The results of the hptII transgene were compared with those of the low copy number, internal standard (hmgr). Using optimised PCR conditions, one, two and three transgene copies in T1 transformants were achieved.

10.
3 Biotech ; 12(2): 53, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35127308

ABSTRACT

Panicle blast is the most severe type of rice blast disease. Screening of rice genotypes for panicle blast resistance at the field level requires an efficient and robust method of inoculation. Here, we standardized a method that can be utilized for both small- and large-scale screening and assessment of panicle blast infection and disease reaction. The method involves inoculation of Magnaporthe oryzae spore culture in the neck of the rice panicle using a syringe and covering the inoculation site with wet cotton wrapped with aluminum foil to provide the required humidity for spore germination. The method was standardized using panicle blast-resistant cv. Tetep and susceptible cv. HP2216 inoculated with Mo-ni-025 isolate of M. oryzae. The method was evaluated at phenotypic as well as molecular level by expression analysis of disease responsive pathogenesis-related (PR) genes. We found this method simple, robust, reliable, and highly efficient for screening of large germplasm sets of rice for panicle blast. This was validated by screening the wild rice germplasm for panicle blast response in the field using three M. oryzae strains and subsequently with the most virulent strain in 45 EMS-induced mutants of Nagina 22 shortlisted based on field screening in a blast hotspot region. We identified five novel blast disease-resistant wild rice genotypes and 15 Nagina 22 mutants that can be used in breeding programmes.

11.
Plant Cell Rep ; 30(10): 1919-28, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21655998

ABSTRACT

Artemisinin, an endoperoxide sesquiterpene lactone, is a novel antimalarial natural product isolated from Artemisia annua L. plants. The low concentrations (0.01-1.1%) of this compound in A. annua L. plants is, however, a major constraint for commercialization of artemisinin-based combination therapies (ACTs) recommended by WHO for treating malaria caused by multidrug-resistant P. falciparum sp. In this context, in vivo yield improvement programs were undertaken by us. In the present study, HMG-Co A reductase gene (hmgr) from Catharanthus roseus (L) G. Don and amorpha-4,11-diene synthase (ads) gene from A. annua L. were over-expressed in A. annua L. plants to study their effects on artemisinin yields. The transgenic lines developed from putative transgenic regenerants were evaluated for integration and copy number of the transgenes using hptII gene probe, as it was a part of the expression cassette. The transgenic lines showed positive bands of hptII gene on Southern blots confirming the integration of transgenes. Some of the transgenic lines had single copy of the transgenes, while others had multiple copies. The expressions of hmgr and ads at the transcriptional level were also confirmed in each transgenic line employing RT-PCR assays. The HPLC analyses showed that the artemisinin contents were significantly increased in these transgenics. One of the transgenic lines, TR4, was found to contain 7.65-fold higher (1.73 mg/gDW) artemisinin than the non-transgenic plant (W). The increased artemisinin levels were found to be correlated with HMG-Co A reductase and amorpha-4,11-diene synthase enzymatic activities in the biochemical analyses.


Subject(s)
Alkyl and Aryl Transferases/metabolism , Artemisia annua/genetics , Artemisinins/metabolism , Hydroxymethylglutaryl CoA Reductases/metabolism , Alkyl and Aryl Transferases/genetics , Artemisia annua/enzymology , Gene Dosage , Gene Expression Regulation, Plant , Genetic Engineering/methods , Hydroxymethylglutaryl CoA Reductases/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified/enzymology , Plants, Genetically Modified/genetics , Transformation, Genetic , Transgenes
12.
J Environ Biol ; 32(1): 51-5, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21888232

ABSTRACT

A broad screening protocol, covering the most general phytochemical groups of compounds, was developed on the basis of high performance thin layer chromatography (HPTLC). A total of six TLC systems, comprising three derivatization reagents, two stationary phases and two mobile phases, were included. The screening method was applied for the identification of biomarkers in the chickpea plant exposed to cadmium and chromium. The biomarkers were selected on the basis of significant changes (0.26-4.6 fold) in concentration levels of phytochemicals. Totally, five different amino acids, three organic acids, one sulphur containing compound and one sugar were identified as biomarkers in chickpea exposed heavy metal.


Subject(s)
Biomarkers/metabolism , Cadmium/toxicity , Chromium/toxicity , Cicer/drug effects , Cicer/metabolism
13.
Front Plant Sci ; 12: 663943, 2021.
Article in English | MEDLINE | ID: mdl-34163503

ABSTRACT

Exogenous application of salicylic acid (SA) has been known for delaying ripening in many fruit and vegetables. But the function of endogenous SA in relation to postharvest fruit performance is still unexplored. To understand the role of endogenous SA in postharvest fruit ripening of tomato, 33 tomato lines were examined for their endogenous SA content, membrane stability index (MSI), and shelf life (SL) at turning and red stages of tomato fruit ripening. Six tomato lines having contrasting shelf lives from these categories were subjected further for ethylene (ET) evolution, 1-aminocyclopropane-1-carboxylic acid synthase (ACS), 1-aminocyclopropane-1-carboxylic acid oxidase (ACO), polygalacturonase (PG), pectin methyl esterase (PME), antioxidant assays and lipid peroxidation. It was found that high endogenous SA has a direct association with low ET evolution, which leads to the high SL of fruit. High lycopene content was also found to be correlated with high SA. Total antioxidants, PG, and PME decreased and lipid peroxidation increased from turning to red stage of tomato fruit development. Furthermore, these lines were subjected to expression analysis for SA biosynthesis enzymes viz. Solanum lycopersicum Isochorismate Synthase (SlICS) and SlPAL. Real-time PCR data revealed that high SL lines have high SlPAL4 expression and low SL lines have high SlPAL6 expression. Based on the results obtained in this study, it was concluded that endogenous SA regulates ET evolution and SL with the aid of the antioxidative defense system, and SlPAL4 and SlPAL6 genes play significant but opposite roles during fruit ripening.

14.
CNS Neurol Disord Drug Targets ; 20(2): 125-144, 2021.
Article in English | MEDLINE | ID: mdl-33138766

ABSTRACT

Amongst the various diseases on a global scale, the second leading cause of mortality and morbidity is ischemic stroke due to the unavailability of an effective therapy. With the growing occurrence and its related health risks along with the absence of effective therapeutics, ischemic stroke demands the continued and intensive research to explore effective and safe therapeutics. These therapies may positively affect the numerous pathways associated with neuroprotection, thus, extending the advantages to a larger population of stroke patients. Several preclinical studies employing neuroprotectants have shown promising outcomes, but failed in clinical trials either because of the lack of safety or efficacy. The Blood-Brain Barrier (BBB) restricts the delivery of various potent neuroprotectants to the specific areas of the brain. The application of nanovehicles for the delivery of drugs in the brain, however, could revolutionize the treatment of ischemic stroke. These nanovehicles loaded with the drug could readily traverse the BBB via carrier, receptor and adsorptive-mediated endocytosis into the brain without compromising the integrity of the BBB. Recent advances in neuronanotherapeutics have resulted in improved neuronal regeneration and recovery after ischemic stroke. In this review, we have attempted to discuss unexploited neuronanotherapeutics potentials to treat and manage ischemic stroke.


Subject(s)
Brain Ischemia/drug therapy , Ischemic Stroke/drug therapy , Nanomedicine/methods , Animals , Blood-Brain Barrier/metabolism , Brain/metabolism , Disease Management , Humans , Neuroprotection/drug effects , Neuroprotective Agents/pharmacology
15.
Arch Microbiol ; 192(6): 409-25, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20358179

ABSTRACT

Filamentous cosmopolitan fungi of the genus Aspergillus can be harmful in two ways, directly they can be opportunistic pathogens causing aspergillosis and indirectly due to aflatoxin production on food products which can lead to aflatoxicosis. Therefore, a number of methods have been proposed so far for detection of the fungi with lowest possible concentration at the earliest. Molecular methods such as PCR and/or in combination with certain techniques have been found to be useful for Aspergillus detection. We discuss here various technologies that have emerged in recent years and can possibly be used for the molecular detection of Aspergillus in an efficient way. These methods like RSIC, C-probe, and inversion probe with pyrosequencing or direct ss/dsDNA detection have been used for the identification of fungal or bacterial pathogens and thus formulate a 'gold standard' for Aspergillus detection.


Subject(s)
Aspergillosis/diagnosis , Aspergillus/classification , Aspergillus/isolation & purification , Food Microbiology , Mycological Typing Techniques/methods , Aflatoxins/metabolism , Animals , Aspergillosis/microbiology , Aspergillus/genetics , DNA Fingerprinting , DNA, Fungal/analysis , DNA, Fungal/genetics , Genetic Techniques , Mycology/methods , Oligonucleotide Array Sequence Analysis , Polymerase Chain Reaction/methods , Retroelements
16.
J Environ Biol ; 29(5): 661-8, 2008 Sep.
Article in English | MEDLINE | ID: mdl-19295061

ABSTRACT

Field-grown Psoralea corylifolia plants were exposed to 0.5 ppm and 1.0 ppm concentrations of sulphur dioxide gas and sampled for observation at the pre-flowering, flowering and post-flowering stages of plant ontogeny. One ppm SO2 concentration caused a significant decline in leaf number and leaf area per plant, total leaf dry weight, and the size and amount of midrib vasculature. The density and size of stomata decreased and many stomata were damaged. Interestingly new epidermis developed oversome of the damaged leaf stomata, thus showing a unique defence strategy against SO2 stress through dedifferentiation of the epidermal cells. Decline in the concentrations of leafchlorophylls and carotenoids in treated plants were up to 20% and 29% respectively. Stomatal conductance, intercellular CO2 content and net photosynthetic rate lowered byover 52%, 20% and 35%, respectively under the SO2 stress. Concentration of psoralen, a basic linear furanocoumarin known for its use in the treatment of dermal diseases, was highest (5.32%) in seeds and lowest (0.28%) in roots. It was heavily reduced in SO2 treated plants, the maximum decline occurring in seeds (86.70%) and leaves (56.27%). In the roots and shoots of the treated plants, it was low in pre-flowering stage, compared with the control, but showed a recovery during the post-flowering phase of plant growth.


Subject(s)
Ficusin/metabolism , Psoralea/drug effects , Sulfur Dioxide/pharmacology , Carotenoids/metabolism , Cell Differentiation/drug effects , Chlorophyll/metabolism , Ficusin/isolation & purification , Photosynthesis/drug effects , Plant Leaves/anatomy & histology , Plant Leaves/drug effects , Plant Leaves/physiology , Plant Stomata/drug effects , Plant Stomata/ultrastructure , Psoralea/anatomy & histology , Psoralea/physiology
18.
J Ethnopharmacol ; 113(3): 503-9, 2007 Sep 25.
Article in English | MEDLINE | ID: mdl-17720339

ABSTRACT

Phyllanthus amarus Schum. et Thonn. (Bhuia amla; Euphorbiacae) is a herb common to central and southern India. It is an ayurvedic herb and has a wide range of traditional uses in different diseases. The aim of this work was to evaluate the hepatoprotective effect of ethanolic extract of Phyllanthus amarus (Phyllanthus amarus) on aflatoxin B(1)-induced liver damage in mice using different biochemical parameters and histopathological studies. Aflatoxin was administered orally (66.6 microg kg(-1)BW 0.2 ml(-1)day(-1)) to the mice of each group except control to which normal saline and ascorbic acid (0.1g kg(-1)BW 0.2 ml(-1)day(-1)) were given, respectively. Ethanolic extract of Phyllanthus amarus (0.3g kg(-1)BW 0.2 ml(-1)day(-1)) was given to all groups except control groups (gp. I and gp. V) after 30 min of aflatoxin administration. The entire study was carried out for 3 months and animals were sacrificed after an interval of 30 days till the completion of study. Phyllanthus amarus extract was found to show hepatoprotective effect by lowering down the content of thiobarbituric acid reactive substances (TBARS) and enhancing the reduced glutathione level and the activities of antioxidant enzymes, glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT). Histopathological analyses of liver samples also confirmed the hepatoprotective value and antioxidant activity of the ethanolic extract of the herb, which was comparable to the standard antioxidant, ascorbic acid. The overall data indicated that Phyllanthus amarus possesses a potent protective effect against aflatoxin B(1)-induced hepatic damage, and the main mechanism involved in the protection could be associated with its strong capability to reduce the intracellular level of reactive oxygen species by enhancing the level of both enzymatic and non-enzymatic antioxidants.


Subject(s)
Liver Diseases/prevention & control , Phyllanthus/chemistry , Phytotherapy , Protective Agents/therapeutic use , Aflatoxin B1 , Animals , Catalase/metabolism , Chemical and Drug Induced Liver Injury , Ethanol/chemistry , Glutathione/metabolism , Glutathione Peroxidase/metabolism , Glutathione Transferase/metabolism , Liver Diseases/metabolism , Liver Diseases/pathology , Male , Mice , Plant Extracts/therapeutic use , Superoxide Dismutase/metabolism , Thiobarbituric Acid Reactive Substances/metabolism
19.
Nat Prod Res ; 31(14): 1713-1716, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28278673

ABSTRACT

Determination of endogenous levels of jasmonic acid (JA) is essential, as it plays a pivotal role in the physiological processes during a plant's life cycle. A high performance thin layer chromatography (HPTLC) method was developed for the detection and quantification of JA in leaf extracts of medicinal plant, Stevia rebaudiana (Bertoni) Bertoni. The separation was achieved using the solvents ethyl acetate-benzene (1:1, v/v) as the mobile phase, followed by scanning and quantification at 295 nm. Densitometric analysis of leaf extract resulted in compact spots for JA at Rf = 0.45 ± 0.02. The linear regression analysis showed good relationship with r value. The recovery rate of JA indicated good reproducibility and repeatability of the assay. The statistical analysis proved the reproducibility of the method; therefore, it can be employed for routine quantification of JA in different tissue samples of S. rebaudiana and may also be extrapolated to other biological samples.


Subject(s)
Cyclopentanes/analysis , Oxylipins/analysis , Stevia/chemistry , Acetates , Benzene , Chromatography, Thin Layer/methods , Cyclopentanes/standards , Oxylipins/standards , Plant Extracts/analysis , Plant Leaves/chemistry , Reproducibility of Results
20.
Front Plant Sci ; 8: 2049, 2017.
Article in English | MEDLINE | ID: mdl-29312363

ABSTRACT

The root-knot nematode (RKN), Meloidogyne incognita, is an obligate, sedentary endoparasite that infects a large number of crops and severely affects productivity. The commonly used nematode control strategies have their own limitations. Of late, RNA interference (RNAi) has become a popular approach for the development of nematode resistance in plants. Transgenic crops capable of expressing dsRNAs, specifically in roots for disrupting the parasitic process, offer an effective and efficient means of producing resistant crops. We identified nematode-responsive and root-specific (NRRS) promoters by using microarray data from the public domain and known conserved cis-elements. A set of 51 NRRS genes was identified which was narrowed down further on the basis of presence of cis-elements combined with minimal expression in the absence of nematode infection. The comparative analysis of promoters from the enriched NRRS set, along with earlier reported nematode-responsive genes, led to the identification of specific cis-elements. The promoters of two candidate genes were used to generate transgenic plants harboring promoter GUS constructs and tested in planta against nematodes. Both promoters showed preferential expression upon nematode infection, exclusively in the root in one and galls in the other. One of these NRRS promoters was used to drive the expression of splicing factor, a nematode-specific gene, for generating host-delivered RNAi-mediated nematode-resistant plants. Transgenic lines expressing dsRNA of splicing factor under the NRRS promoter exhibited upto a 32% reduction in number of galls compared to control plants.

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