Displaying publications 41 - 60 of 148 in total

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  1. Fulltext Evaluation of reference genes for quantitative real-time PCR in oil palm elite planting materials propagated by tissue culture
    Chan PL, Rose RJ, Abdul Murad AM, Zainal Z, Low ET, Ooi LC, et al.
    PLoS One, 2014;9(6):e99774.
    PMID: 24927412 DOI: 10.1371/journal.pone.0099774
    The somatic embryogenesis tissue culture process has been utilized to propagate high yielding oil palm. Due to the low callogenesis and embryogenesis rates, molecular studies were initiated to identify genes regulating the process, and their expression levels are usually quantified using reverse transcription quantitative real-time PCR (RT-qPCR). With the recent release of oil palm genome sequences, it is crucial to establish a proper strategy for gene analysis using RT-qPCR. Selection of the most suitable reference genes should be performed for accurate quantification of gene expression levels.
    Matched MeSH terms: Gene Expression Regulation, Plant
  2. A Comprehensive Gene Inventory for Glucosinolate Biosynthetic Pathway in Arabidopsis thaliana
    Harun S, Abdullah-Zawawi MR, Goh HH, Mohamed-Hussein ZA
    J Agric Food Chem, 2020 Jul 15;68(28):7281-7297.
    PMID: 32551569 DOI: 10.1021/acs.jafc.0c01916
    Glucosinolates (GSLs) are plant secondary metabolites comprising sulfur and nitrogen mainly found in plants from the order of Brassicales, such as broccoli, cabbage, and Arabidopsis thaliana. The activated forms of GSL play important roles in fighting against pathogens and have health benefits to humans. The increasing amount of data on A. thaliana generated from various omics technologies can be investigated more deeply in search of new genes or compounds involved in GSL biosynthesis and metabolism. This review describes a comprehensive inventory of A. thaliana GSLs identified from published literature and databases such as KNApSAcK, KEGG, and AraCyc. A total of 113 GSL genes encoding for 23 transcription components, 85 enzymes, and five protein transporters were experimentally characterized in the past two decades. Continuous efforts are still on going to identify all molecules related to the production of GSLs. A manually curated database known as SuCCombase (http://plant-scc.org) was developed to serve as a comprehensive GSL inventory. Realizing lack of information on the regulation of GSL biosynthesis and degradation mechanisms, this review also includes relevant information and their connections with crosstalk among various factors, such as light, sulfur metabolism, and nitrogen metabolism, not only in A. thaliana but also in other crucifers.
    Matched MeSH terms: Gene Expression Regulation, Plant
  3. Genetic diversity and in silico evidence of target-site mutation in the EPSPS gene in endowing glyphosate resistance in Eleusine indica (L.) from Malaysia
    Franci J, Lam KW, Chuah TS, Cha TS
    Pestic Biochem Physiol, 2020 May;165:104556.
    PMID: 32359543 DOI: 10.1016/j.pestbp.2020.104556
    Glyphosate-resistant populations of Eleusine indica are widespread in several states of Malaysia. A whole-plant bioassay confirmed that eight out of the 17 populations tested were resistant to glyphosate at double the recommended rate of 2.44 kg ha-1. Screening with allele-specific PCR (AS-PCR) revealed that resistant plants contained an EPSPS gene with either the homozygous S/S-106 or the heterozygous P/S-106 alleles. All susceptible plants contained only the homozygous P/P-106 allele. In addition, DNA sequences of the full-length EPSPS gene from one susceptible (SB) and four resistant (R2, R6, R8 and R11) populations revealed an amino acid substitution of T102I in all the resistant plants, while another substitution of P381L was only found in resistant populations R6 and R11. The significance of the P381L mutation was examined by Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) and residue interaction network (RIN) analyses, which suggests the P381L mutation may contribute to resistance. Mutations at 102 and 106 occur widely in the EPSPS gene of glyphosate-resistant E. indica populations from Malaysia with the TIPS mutation. In addition, the P381L mutation could also contribute to resistance.
    Matched MeSH terms: Gene Expression Regulation, Plant
  4. An Overview of Molecular Basis and Genetic Modification of Floral Organs Genes: Impact of Next-Generation Sequencing
    Patil RV, Hadawale KN, Ramli ANM, Wadkar SS, Bhuyar P
    Mol Biotechnol, 2023 Jun;65(6):833-848.
    PMID: 36544065 DOI: 10.1007/s12033-022-00633-7
    In plant development, flowering is the most widely studied process. Floral forms show large diversity in different species due to simple variations in basic architecture. To determine the floral gene expression during the past decade, MADS-box genes have identified as key regulators in both reproductive and vegetative plant development. Traditional genetics and functional genomics tools are now available to elucidate the expression and function of this complex gene family on a much larger scale. Moreover, comparative analysis of the MADS-box genes in diverse flowering and non-flowering plants, boosted by various molecular technologies such as ChIP and next-generation DNA sequencing, contributes to our understanding of how this important gene family has expanded during the evolution of land plants. Likewise, the big data analysis revealed combined activity of transcriptional regulators and floral organ identity factors regulate the flower developmental programs. Thus, with the help of cutting-edge technologies like RNA-Sequencing, sex determination is now better understood in few non-model plants Therefore, the recent advances in next-generation sequencing (NGS) should enable researchers to identify the full range of floral gene functions, which will significantly help to understand plant development and evolution. This review summarizes the floral homeotic genes in model and non-model species to understand the flower development genes and dioecy evolution.
    Matched MeSH terms: Gene Expression Regulation, Plant
  5. Fulltext DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium hybrid
    Khairul-Anuar MA, Mazumdar P, Othman RY, Harikrishna JA
    Ann Bot, 2022 Sep 26;130(4):579-594.
    PMID: 35980362 DOI: 10.1093/aob/mcac103
    BACKGROUND: Flower pigment and shape are determined by the coordinated expression of a set of structural genes during flower development. R2R3-MYB transcription factors are known regulators of structural gene expression. The current study focused on two members of this large family of transcription factors that were predicted to have roles in pigment biosynthesis and organ shape development in orchids.

    METHODS: Phylogenetic analysis was used to identify candidate Dendrobium catenatum R2R3-MYB (DcaMYB) sequences associated with pigment and cell shape development. Gene silencing of candidate DhMYBs in Dendrobium hybrid by direct application of dsRNA to developing flowers was followed by observation of gene expression level and flower phenotypes. Silencing of the structural gene chalcone synthase was used as a comparative control.

    KEY RESULTS: Ten candidate flower-associated DcaMYBs were identified. Flowers treated with dsRNA of DhMYB22 and DhMYB60 sequences were less pigmented and had relatively low expression of anthocyanin biosynthetic genes (F3'H and DFR), lower total anthocyanin concentration and markedly lower levels of cyanidin-3-glucoside and cyanidin-3-rutinoside. Petals of DhMYB22-treated flowers and sepals of DhMYB60-treated flowers showed the greatest colour difference relative to the same organs in untreated flowers. DhMYB22-treated flowers had relatively narrow and constricted lips, while DhMYB60-treated flowers had narrow and constricted sepals. No significant difference in shape was observed for DhCHS-treated or untreated flowers.

    CONCLUSIONS: Our results demonstrate that DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium. This is a first report of MYB regulation of floral organ shape in orchids.

    Matched MeSH terms: Gene Expression Regulation, Plant
  6. Variable expansin expression in Arabidopsis leads to different growth responses
    Goh HH, Sloan J, Malinowski R, Fleming A
    J Plant Physiol, 2014 Feb 15;171(3-4):329-39.
    PMID: 24144490 DOI: 10.1016/j.jplph.2013.09.009
    Expansins have long been implicated in the control of cell wall extensibility. However, despite ample evidence supporting a role for these proteins in the endogenous mechanism of plant growth, there are also examples in the literature where the outcome of altered expansin gene expression is difficult to reconcile with a simplistic causal linkage to growth promotion. To investigate this problem, we report on the analysis of transgenic Arabidopsis plants in which a heterologous cucumber expansin can be inducibly overexpressed. Our results indicate that the effects of expansin expression on growth depend on the degree of induction of expansin expression and the developmental pattern of organ growth. They support the role of expansin in directional cell expansion. They are also consistent with the idea that excess expansin might itself impede normal activities of cell wall modifications, culminating in both growth promotion and repression depending on the degree of expression.
    Matched MeSH terms: Gene Expression Regulation, Plant
  7. Fulltext Expression of the Arabidopsis redox-related LEA protein, SAG21 is regulated by ERF, NAC and WRKY transcription factors
    Evans KV, Ransom E, Nayakoti S, Wilding B, Mohd Salleh F, Gržina I, et al.
    Sci Rep, 2024 Apr 02;14(1):7756.
    PMID: 38565965 DOI: 10.1038/s41598-024-58161-0
    SAG21/LEA5 is an unusual late embryogenesis abundant protein in Arabidopsis thaliana, that is primarily mitochondrially located and may be important in regulating translation in both chloroplasts and mitochondria. SAG21 expression is regulated by a plethora of abiotic and biotic stresses and plant growth regulators indicating a complex regulatory network. To identify key transcription factors regulating SAG21 expression, yeast-1-hybrid screens were used to identify transcription factors that bind the 1685 bp upstream of the SAG21 translational start site. Thirty-three transcription factors from nine different families bound to the SAG21 promoter, including members of the ERF, WRKY and NAC families. Key binding sites for both NAC and WRKY transcription factors were tested through site directed mutagenesis indicating the presence of cryptic binding sites for both these transcription factor families. Co-expression in protoplasts confirmed the activation of SAG21 by WRKY63/ABO3, and SAG21 upregulation elicited by oligogalacturonide elicitors was partially dependent on WRKY63, indicating its role in SAG21 pathogen responses. SAG21 upregulation by ethylene was abolished in the erf1 mutant, while wound-induced SAG21 expression was abolished in anac71 mutants, indicating SAG21 expression can be regulated by several distinct transcription factors depending on the stress condition.
    Matched MeSH terms: Gene Expression Regulation, Plant
  8. Fulltext Comparative transcriptome analysis of leaves and roots in response to sudden increase in salinity in Brassica napus by RNA-seq
    Yong HY, Zou Z, Kok EP, Kwan BH, Chow K, Nasu S, et al.
    Biomed Res Int, 2014;2014:467395.
    PMID: 25177691 DOI: 10.1155/2014/467395
    Amphidiploid species in the Brassicaceae family, such as Brassica napus, are more tolerant to environmental stress than their diploid ancestors.A relatively salt tolerant B. napus line, N119, identified in our previous study, was used. N119 maintained lower Na(+) content, and Na(+)/K(+) and Na(+)/Ca(2+) ratios in the leaves than a susceptible line. The transcriptome profiles of both the leaves and the roots 1 h and 12 h after stress were investigated. De novo assembly of individual transcriptome followed by sequence clustering yielded 161,537 nonredundant sequences. A total of 14,719 transcripts were differentially expressed in either organs at either time points. GO and KO enrichment analyses indicated that the same 49 GO terms and seven KO terms were, respectively, overrepresented in upregulated transcripts in both organs at 1 h after stress. Certain overrepresented GO term of genes upregulated at 1 h after stress in the leaves became overrepresented in genes downregulated at 12 h. A total of 582 transcription factors and 438 transporter genes were differentially regulated in both organs in response to salt shock. The transcriptome depicting gene network in the leaves and the roots regulated by salt shock provides valuable information on salt resistance genes for future application to crop improvement.
    Matched MeSH terms: Gene Expression Regulation, Plant/physiology
  9. Fulltext The oil palm VIRESCENS gene controls fruit colour and encodes a R2R3-MYB
    Singh R, Low ET, Ooi LC, Ong-Abdullah M, Nookiah R, Ting NC, et al.
    Nat Commun, 2014 Jun 30;5:4106.
    PMID: 24978855 DOI: 10.1038/ncomms5106
    Oil palm, a plantation crop of major economic importance in Southeast Asia, is the predominant source of edible oil worldwide. We report the identification of the virescens (VIR) gene, which controls fruit exocarp colour and is an indicator of ripeness. VIR is a R2R3-MYB transcription factor with homology to Lilium LhMYB12 and similarity to Arabidopsis production of anthocyanin pigment1 (PAP1). We identify five independent mutant alleles of VIR in over 400 accessions from sub-Saharan Africa that account for the dominant-negative virescens phenotype. Each mutation results in premature termination of the carboxy-terminal domain of VIR, resembling McClintock's C1-I allele in maize. The abundance of alleles likely reflects cultural practices, by which fruits were venerated for magical and medicinal properties. The identification of VIR will allow selection of the trait at the seed or early-nursery stage, 3-6 years before fruits are produced, greatly advancing introgression into elite breeding material.
    Matched MeSH terms: Gene Expression Regulation, Plant*
  10. Fulltext Characterization of microRNAs expressed during secondary wall biosynthesis in Acacia mangium
    Ong SS, Wickneswari R
    PLoS One, 2012;7(11):e49662.
    PMID: 23251324 DOI: 10.1371/journal.pone.0049662
    MicroRNAs (miRNAs) play critical regulatory roles by acting as sequence specific guide during secondary wall formation in woody and non-woody species. Although thousands of plant miRNAs have been sequenced, there is no comprehensive view of miRNA mediated gene regulatory network to provide profound biological insights into the regulation of xylem development. Herein, we report the involvement of six highly conserved amg-miRNA families (amg-miR166, amg-miR172, amg-miR168, amg-miR159, amg-miR394, and amg-miR156) as the potential regulatory sequences of secondary cell wall biosynthesis. Within this highly conserved amg-miRNA family, only amg-miR166 exhibited strong differences in expression between phloem and xylem tissue. The functional characterization of amg-miR166 targets in various tissues revealed three groups of HD-ZIP III: ATHB8, ATHB15, and REVOLUTA which play pivotal roles in xylem development. Although these three groups vary in their functions, -psRNA target analysis indicated that miRNA target sequences of the nine different members of HD-ZIP III are always conserved. We found that precursor structures of amg-miR166 undergo exhaustive sequence variation even within members of the same family. Gene expression analysis showed three key lignin pathway genes: C4H, CAD, and CCoAOMT were upregulated in compression wood where a cascade of miRNAs was downregulated. This study offers a comprehensive analysis on the involvement of highly conserved miRNAs implicated in the secondary wall formation of woody plants.
    Matched MeSH terms: Gene Expression Regulation, Plant*
  11. Transcriptome profiling of genes induced by salicylic acid and methyl jasmonate in Polygonum minus
    Ee SF, Oh JM, Mohd Noor N, Kwon TR, Mohamed-Hussein ZA, Ismail I, et al.
    Mol Biol Rep, 2013 Mar;40(3):2231-41.
    PMID: 23187733 DOI: 10.1007/s11033-012-2286-4
    The importance of plant secondary metabolites for both mankind and the plant itself has long been established. However, despite extensive research on plant secondary metabolites, plant secondary metabolism and its regulation still remained poorly characterized. In this present study, cDNA-amplified fragment length polymorphism (cDNA-AFLP) transcript profiling was applied to generate the expression profiles of Polygonum minus in response to salicylic acid (SA) and methyl jasmonate (MeJA) elicitations. This study reveals two different sets of genes induced by SA and MeJA, respectively where stress-related genes were proved to lead to the expression of genes involved in plant secondary metabolite biosynthetic pathways. A total of 98 transcript-derived fragments (TDFs) were up-regulated, including 46 from SA-treated and 52 from MeJA-treated samples. The cDNA-AFLP transcripts generated using 64 different Mse1/Taq1 primer combinations showed that treatments with SA and MeJA induced genes mostly involved in scavenging reactive oxygen species, including zeaxanthin epoxidase, cytosolic ascorbate peroxidase 1 and peroxidase. Of these stress-related genes, 15 % of other annotated TDFs are involved mainly in secondary metabolic processes where among these, two genes encoding (+)-delta cadinene synthase and cinnamoyl-CoA reductase were highlighted.
    Matched MeSH terms: Gene Expression Regulation, Plant/drug effects*
  12. Fulltext Identification of four functionally important microRNA families with contrasting differential expression profiles between drought-tolerant and susceptible rice leaf at vegetative stage
    Cheah BH, Nadarajah K, Divate MD, Wickneswari R
    BMC Genomics, 2015;16:692.
    PMID: 26369665 DOI: 10.1186/s12864-015-1851-3
    Developing drought-tolerant rice varieties with higher yield under water stressed conditions provides a viable solution to serious yield-reduction impact of drought. Understanding the molecular regulation of this polygenic trait is crucial for the eventual success of rice molecular breeding programmes. microRNAs have received tremendous attention recently due to its importance in negative regulation. In plants, apart from regulating developmental and physiological processes, microRNAs have also been associated with different biotic and abiotic stresses. Hence here we chose to analyze the differential expression profiles of microRNAs in three drought treated rice varieties: Vandana (drought-tolerant), Aday Sel (drought-tolerant) and IR64 (drought-susceptible) in greenhouse conditions via high-throughput sequencing.
    Matched MeSH terms: Gene Expression Regulation, Plant*
  13. Metabolomics and its role in understanding cellular responses in plants
    Bhalla R, Narasimhan K, Swarup S
    Plant Cell Rep, 2005 Dec;24(10):562-71.
    PMID: 16220342
    A natural shift is taking place in the approaches being adopted by plant scientists in response to the accessibility of systems-based technology platforms. Metabolomics is one such field, which involves a comprehensive non-biased analysis of metabolites in a given cell at a specific time. This review briefly introduces the emerging field and a range of analytical techniques that are most useful in metabolomics when combined with computational approaches in data analyses. Using cases from Arabidopsis and other selected plant systems, this review highlights how information can be integrated from metabolomics and other functional genomics platforms to obtain a global picture of plant cellular responses. We discuss how metabolomics is enabling large-scale and parallel interrogation of cell states under different stages of development and defined environmental conditions to uncover novel interactions among various pathways. Finally, we discuss selected applications of metabolomics.
    Matched MeSH terms: Gene Expression Regulation, Plant/genetics
  14. Leaf transcriptomic signatures for somatic embryogenesis potential of Elaeis guineensis
    Ooi SE, Feshah I, Nuraziyan A, Sarpan N, Ata N, Lim CC, et al.
    Plant Cell Rep, 2021 Jul;40(7):1141-1154.
    PMID: 33929599 DOI: 10.1007/s00299-021-02698-1
    KEY MESSAGE: Potentially embryogenic oil palms can be identified through leaf transcriptomic signatures. Differential expression of genes involved in flowering time, and stress and light responses may associate with somatic embryogenesis potential. Clonal propagation is an attractive approach for the mass propagation of high yielding oil palms. A major issue hampering the effectiveness of oil palm tissue culture is the low somatic embryogenesis rate. Previous studies have identified numerous genes involved in oil palm somatic embryogenesis, but their association with embryogenic potential has not been determined. In this study, differential expression analysis of leaf transcriptomes from embryogenic and non-embryogenic mother palms revealed that transcriptome profiles from non- and poor embryogenic mother palms were more similar than highly embryogenic palms. A total of 171 genes exhibiting differential expression in non- and low embryogenesis groups could also discriminate high from poor embryogenesis groups of another tissue culture agency. Genes related to flowering time or transition such as FTIP, FRIGIDA-LIKE, and NF-YA were up-regulated in embryogenic ortets, suggesting that reproduction timing of the plant may associate with somatic embryogenesis potential. Several light response or photosynthesis-related genes were down-regulated in embryogenic ortets, suggesting a link between photosynthesis activity and embryogenic potential. As expression profiles of the differentially expressed genes are very similar between non- and low embryogenic groups, machine learning approaches with several candidate genes may generate a more sensitive model to better discriminate non-embryogenic from embryogenic ortets.
    Matched MeSH terms: Gene Expression Regulation, Plant*
  15. Fulltext 'Movers and shakers' in the regulation of fruit ripening: a cross-dissection of climacteric versus non-climacteric fruit
    Cherian S, Figueroa CR, Nair H
    J Exp Bot, 2014 Sep;65(17):4705-22.
    PMID: 24994760 DOI: 10.1093/jxb/eru280
    Fruit ripening is a complex and highly coordinated developmental process involving the expression of many ripening-related genes under the control of a network of signalling pathways. The hormonal control of climacteric fruit ripening, especially ethylene perception and signalling transduction in tomato has been well characterized. Additionally, great strides have been made in understanding some of the major regulatory switches (transcription factors such as RIPENING-INHIBITOR and other transcriptional regulators such as COLOURLESS NON-RIPENING, TOMATO AGAMOUS-LIKE1 and ETHYLENE RESPONSE FACTORs), that are involved in tomato fruit ripening. In contrast, the regulatory network related to non-climacteric fruit ripening remains poorly understood. However, some of the most recent breakthrough research data have provided several lines of evidences for abscisic acid- and sucrose-mediated ripening of strawberry, a non-climacteric fruit model. In this review, we discuss the most recent research findings concerning the hormonal regulation of fleshy fruit ripening and their cross-talk and the future challenges taking tomato as a climacteric fruit model and strawberry as a non-climacteric fruit model. We also highlight the possible contribution of epigenetic changes including the role of plant microRNAs, which is opening new avenues and great possibilities in the fields of fruit-ripening research and postharvest biology.
    Matched MeSH terms: Gene Expression Regulation, Plant*
  16. Fulltext Solar rhythm in the regulation of photoperiodic flowering of long-day and short-day plants
    Yeang HY
    J Exp Bot, 2013 Jul;64(10):2643-52.
    PMID: 23645867 DOI: 10.1093/jxb/ert130
    In photoperiodic flowering, long-day (LD) plants are induced to flower seasonally when the daylight hours are long, whereas flowering in short-day (SD) plants is promoted under short photoperiods. According to the widely accepted external coincidence model, flowering occurs in LD Arabidopsis when the circadian rhythm of the gene CONSTANS (CO) peaks in the afternoon, when it is light during long days but dark when the days are short. Nevertheless, extending this explanation to SD flowering in rice, Oriza sativa, requires LD and SD plants to have 'opposite light requirements' as the CO orthologue in rice, HEADING-DATE1 (Hd1), promotes flowering only under short photoperiods. This report proposes a role of the plant's solar rhythm in promoting seasonal flowering. The interaction between rhythmic genes entrained to the solar clock and those entrained to the circadian clock form the basis of an internal coincidence model that explains both LD and SD flowering equally well. The model invokes no presumption of opposite light requirements between LD and SD plants, and further argues against any specific requirement of either light or darkness for SD flowering. Internal coincidence predicts the inhibition of SD flowering of the rice plant by a night break (a brief interruption of light), while it also provides a plausible explanation for how a judiciously timed night break promotes Arabidopsis flowering even on short days. It is the timing of the light transitions (sunrise and sunset) rather than the duration of light or darkness per se that regulates photoperiod-controlled flowering.
    Matched MeSH terms: Gene Expression Regulation, Plant/radiation effects
  17. Fulltext Comparative transcriptome analysis to identify candidate genes involved in 2-methoxy-1,4-naphthoquinone (MNQ) biosynthesis in Impatiens balsamina L
    Foong LC, Chai JY, Ho ASH, Yeo BPH, Lim YM, Tam SM
    Sci Rep, 2020 09 30;10(1):16123.
    PMID: 32999341 DOI: 10.1038/s41598-020-72997-2
    Impatiens balsamina L. is a tropical ornamental and traditional medicinal herb rich in natural compounds, especially 2-methoxy-1,4-naphthoquinone (MNQ) which is a bioactive compound with tested anticancer activities. Characterization of key genes involved in the shikimate and 1,4-dihydroxy-2-naphthoate (DHNA) pathways responsible for MNQ biosynthesis and their expression profiles in I. balsamina will facilitate adoption of genetic/metabolic engineering or synthetic biology approaches to further increase production for pre-commercialization. In this study, HPLC analysis showed that MNQ was present in significantly higher quantities in the capsule pericarps throughout three developmental stages (early-, mature- and postbreaker stages) whilst its immediate precursor, 2-hydroxy-1,4-naphthoquinone (lawsone) was mainly detected in mature leaves. Transcriptomes of I. balsamina derived from leaf, flower, and three capsule developmental stages were generated, totalling 59.643 Gb of raw reads that were assembled into 94,659 unigenes (595,828 transcripts). A total of 73.96% of unigenes were functionally annotated against seven public databases and 50,786 differentially expressed genes (DEGs) were identified. Expression profiles of 20 selected genes from four major secondary metabolism pathways were studied and validated using qRT-PCR method. Majority of the DHNA pathway genes were found to be significantly upregulated in early stage capsule compared to flower and leaf, suggesting tissue-specific synthesis of MNQ. Correlation analysis identified 11 candidate unigenes related to three enzymes (NADH-quinone oxidoreductase, UDP-glycosyltransferases and S-adenosylmethionine-dependent O-methyltransferase) important in the final steps of MNQ biosynthesis based on genes expression profiles consistent with MNQ content. This study provides the first molecular insight into the dynamics of MNQ biosynthesis and accumulation across different tissues of I. balsamina and serves as a valuable resource to facilitate further manipulation to increase production of MNQ.
    Matched MeSH terms: Gene Expression Regulation, Plant/genetics
  18. Molecular cloning, modeling, and site-directed mutagenesis of type III polyketide synthase from Sargassum binderi (Phaeophyta)
    Baharum H, Morita H, Tomitsuka A, Lee FC, Ng KY, Rahim RA, et al.
    Mar Biotechnol (NY), 2011 Oct;13(5):845-56.
    PMID: 21181422 DOI: 10.1007/s10126-010-9344-5
    Type III polyketide synthases (PKSs) produce an array of metabolites with diverse functions. In this study, we have cloned the complete reading frame encoding type III PKS (SbPKS) from a brown seaweed, Sargassum binderi, and characterized the activity of its recombinant protein biochemically. The deduced amino acid sequence of SbPKS is 414 residues in length, sharing a higher sequence similarity with bacterial PKSs (38% identity) than with plant PKSs. The Cys-His-Asn catalytic triad of PKS is conserved in SbPKS with differences in some of the residues lining the active and CoA binding sites. The wild-type SbPKS displayed broad starter substrate specificity to aliphatic long-chain acyl-CoAs (C(6)-C(14)) to produce tri- and tetraketide pyrones. Mutations at H(331) and N(364) caused complete loss of its activity, thus suggesting that these two residues are the catalytic residues for SbPKS as in other type III PKSs. Furthermore, H227G, H227G/L366V substitutions resulted in increased tetraketide-forming activity, while wild-type SbPKS produces triketide α-pyrone as a major product. On the other hand, mutant H227G/L366V/F93A/V95A demonstrated a dramatic decrease of tetraketide pyrone formation. These observations suggest that His(227) and Leu(366) play an important role for the polyketide elongation reaction in SbPKS. The conformational changes in protein structure especially the cavity of the active site may have more significant effect to the activity of SbPKS compared with changes in individual residues.
    Matched MeSH terms: Gene Expression Regulation, Plant/physiology*
  19. Chemical-Induced Inhibition of Blue Light-Mediated Seedling Development Caused by Disruption of Upstream Signal Transduction Involving Cryptochromes in Arabidopsis thaliana
    Ong WD, Okubo-Kurihara E, Kurihara Y, Shimada S, Makita Y, Kawashima M, et al.
    Plant Cell Physiol, 2017 01 01;58(1):95-105.
    PMID: 28011868 DOI: 10.1093/pcp/pcw181
    Plants have a remarkable ability to perceive and respond to various wavelengths of light and initiate regulation of different cascades of light signaling and molecular components. While the perception of red light and the mechanisms of its signaling involving phytochromes are largely known, knowledge of the mechanisms of blue light signaling is still limited. Chemical genetics involves the use of diverse small active or synthetic molecules to evaluate biological processes. By combining chemicals and analyzing the effects they have on plant morphology, we identified a chemical, 3-bromo-7-nitroindazole (3B7N), that promotes hypocotyl elongation of wild-type Arabidopsis only under continuous blue light. Further evaluation with loss-of-function mutants confirmed that 3B7N inhibits photomorphogenesis through cryptochrome-mediated light signaling. Microarray analysis demonstrated that the effect of 3B7N treatment on gene expression in cry1cry2 is considerably smaller than that in the wild type, indicating that 3B7N specifically interrupts cryptochrome function in the control of seedling development in a light-dependent manner. We demonstrated that 3B7N directly binds to CRY1 protein using an in vitro binding assay. These results suggest that 3B7N is a novel chemical that directly inhibits plant cryptochrome function by physical binding. The application of 3B7N can be used on other plants to study further the blue light mechanism and the genetic control of cryptochromes in the growth and development of plant species.
    Matched MeSH terms: Gene Expression Regulation, Plant/drug effects; Gene Expression Regulation, Plant/radiation effects
  20. Fulltext Size dependent effects of antifungal phytogenic silver nanoparticles on germination, growth and biochemical parameters of rice (Oryza sativa L), maize (Zea mays L) and peanut (Arachis hypogaea L)
    Prasad TNVKV, Adam S, Visweswara Rao P, Ravindra Reddy B, Giridhara Krishna T
    IET Nanobiotechnol, 2017 Apr;11(3):277-285.
    PMID: 28476985 DOI: 10.1049/iet-nbt.2015.0122
    Advancement in materials synthesis largely depends up on their diverse applications and commercialisation. Antifungal effects of phytogenic silver nanoparticles (AgNPs) were evident, but the reports on the effects of the same on agricultural crops are scant. Herein, we report for the first time, size dependent effects of phytogenic AgNPs (synthesised using Stevia rebaudiana leaf extract) on the germination, growth and biochemical parameters of three important agricultural crops viz., rice (Oryza sativa L), maize (Zea mays L) and peanut (Arachis hypogaea L). AgNPs with varied sizes were prepared by changing the concentration and quantity of the Stevia rebaudiana leaf extract. As prepared AgNPs were characterized using the techniques, such as high-resolution transmission electron microscopy, particle size and zeta potential analyser. The measured (dynamic light scattering technique) average sizes of particles are ranging from 68.5 to 116 nm. Fourier transform infrared studies confirmed the participation of alcohols, aldehydes and amides in the reduction and stabilisation of the AgNPs. Application of these AgNPs to three agricultural crop seeds (rice, maize and peanut) resulted in size dependent effects on their germination, growth and biochemical parameters such as, chlorophyll content, carotenoid and protein content. Further, antifungal activity of AgNPs also evaluated against fungi, Aspergillus niger.
    Matched MeSH terms: Gene Expression Regulation, Plant/drug effects; Gene Expression Regulation, Plant/physiology
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