Displaying publications 61 - 80 of 109 in total

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  1. Sim YY, Nyam KL
    Food Chem, 2021 May 15;344:128582.
    PMID: 33199120 DOI: 10.1016/j.foodchem.2020.128582
    The electronic database was searched up to July 2020, using keywords, kenaf and roselle, chemical constituents of kenaf and roselle, therapeutic uses of kenaf and roselle. Journals, books and conference proceedings were also searched. Investigations of pharmacological activities of kenaf revealed that this edible plant exhibits a broad range of therapeutic potential including antioxidant, antimicrobial, antityrosinase, anticancer, antihyperlipidemia, antiulcer, anti-inflammatory, and hepatoprotective activities. Kenaf also showed versatile utility as a functional ingredient in food, folk medicine, and animal nutritions, as well as in nanotechnology processes. The exploitation of underexploited kenaf by-products can be a significant part of waste management from an economic and environmental point of view. In addition, kenaf showed comparable nutritional, phytochemical, and pharmacological properties with Hibiscus sabdariffa (Roselle). This review has important implications for further investigations and applications of kenaf in food and pharmaceuticals industry.
    Matched MeSH terms: Plant Proteins/metabolism
  2. Seman-Kamarulzaman AF, Mohamed-Hussein ZA, Ng CL, Hassan M
    PLoS One, 2016;11(8):e0161707.
    PMID: 27560927 DOI: 10.1371/journal.pone.0161707
    Juvenile Hormone III is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. Thus, the elucidation of enzymes involved JH III biosynthetic pathway has become increasing important in recent years. One of the enzymes in the JH III biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. A novel NAD+-farnesal dehydrogenase of Polygonum minus was purified (315-fold) to apparent homogeneity in five chromatographic steps. The purification procedures included Gigacap S-Toyopearl 650M, Gigacap Q-Toyopearl 650M, and AF-Blue Toyopearl 650ML, followed by TSK Gel G3000SW chromatographies. The enzyme, with isoelectric point of 6.6 is a monomeric enzyme with a molecular mass of 70 kDa. The enzyme was relatively active at 40°C, but was rapidly inactivated above 45°C. The optimal temperature and pH of the enzyme were found to be 35°C and 9.5, respectively. The enzyme activity was inhibited by sulfhydryl agent, chelating agent, and metal ion. The enzyme was highly specific for farnesal and NAD+. Other terpene aldehydes such as trans- cinnamaldehyde, citral and α- methyl cinnamaldehyde were also oxidized but in lower activity. The Km values for farnesal, citral, trans- cinnamaldehyde, α- methyl cinnamaldehyde and NAD+ were 0.13, 0.69, 0.86, 1.28 and 0.31 mM, respectively. The putative P. minus farnesal dehydrogenase that's highly specific towards farnesal but not to aliphatic aldehydes substrates suggested that the enzyme is significantly different from other aldehyde dehydrogenases that have been reported. The MALDI-TOF/TOF-MS/MS spectrometry further identified two peptides that share similarity to those of previously reported aldehyde dehydrogenases. In conclusion, the P. minus farnesal dehydrogenase may represent a novel plant farnesal dehydrogenase that exhibits distinctive substrate specificity towards farnesal. Thus, it was suggested that this novel enzyme may be functioning specifically to oxidize farnesal in the later steps of JH III pathway. This report provides a basic understanding for recombinant production of this particular enzyme. Other strategies such as adding His-tag to the protein makes easy the purification of the protein which is completely different to the native protein. Complete sequence, structure and functional analysis of the enzyme will be important for developing insect-resistant crop plants by deployment of transgenic plant.
    Matched MeSH terms: Plant Proteins/metabolism
  3. 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: Plant Proteins/metabolism
  4. Liew YJM, Lee YK, Khalid N, Rahman NA, Tan BC
    Mol Biotechnol, 2021 Apr;63(4):316-326.
    PMID: 33565047 DOI: 10.1007/s12033-021-00304-z
    Prenylation of aromatic natural products by membrane-bound prenyltransferases (PTs) is an important biosynthesis step of many bioactive compounds. At present, only a few plant flavonoid-related PT genes have been functionally characterized, mainly due to the difficulties of expressing these membrane proteins. Rapid and effective methods to produce functional plant membrane proteins are thus indispensable. Here, we evaluated expression systems through cell-based and cell-free approaches to express Boesenbergia rotunda BrPT2 encoding a membrane-bound prenyltransferase. We attempted to express BrPT2 in Escherichia coli and tobacco plants but failed to detect this protein using the Western-blot technique, whereas an intact single band of 43 kDa was detected when BrPT2 was expressed using a cell-free protein synthesis system (PURE). Under in vitro enzymatic condition, the synthesized BrPT2 successfully catalyzed pinostrobin chalcone to pinostrobin. Molecular docking analysis showed that pinostrobin chalcone interacts with BrPT2 at two cavities: (1) the main binding site at the central cavity and (2) the allosteric binding site located away from the central cavity. Our findings suggest that cell-free protein synthesis could be an alternative for rapid production of valuable difficult-to-express membrane proteins.
    Matched MeSH terms: Plant Proteins/metabolism
  5. Shultana R, Kee Zuan AT, Yusop MR, Saud HM, El-Shehawi AM
    PLoS One, 2021;16(12):e0260869.
    PMID: 34898612 DOI: 10.1371/journal.pone.0260869
    Soil salinity exert negative impacts on agricultural production and regarded as a crucial issue in global wetland rice production (Oryza sativa L.). Indigenous salt-tolerant plant growth-promoting rhizobacteria (Bacillus sp.) could be used for improving rice productivity under salinity stress. This study screened potential salt-tolerant plant growth-promoting rhizobacteria (PGPR) collected from coastal salt-affected rice cultivation areas under laboratory and glasshouse conditions. Furthermore, the impacts of these PGPRs were tested on biochemical attributes and nutrient contents in various rice varieties under salt stress. The two most promising PGPR strains, i.e., 'UPMRB9' (Bacillus tequilensis 10b) and 'UPMRE6' (Bacillus aryabhattai B8W22) were selected for glasshouse trial. Results indicated that 'UPMRB9' improved osmoprotectant properties, i.e., proline and total soluble sugar (TSS), antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT). Moreover, 'UPMRB9' inoculated rice plants accumulated higher amount of nitrogen and calcium in tissues. Therefore, the indigenous salt-tolerant PGPR strain 'UPMRB9' could be used as a potential bio-augmentor for improving biochemical attributes and nutrient uptake in rice plants under salinity stress. This study could serve as a preliminary basis for future large-scale trials under glasshouse and field conditions.
    Matched MeSH terms: Plant Proteins/metabolism
  6. Chen J, Jiang C, Huang H, Wei S, Huang Z, Wang H, et al.
    Pestic Biochem Physiol, 2017 Nov;143:201-206.
    PMID: 29183593 DOI: 10.1016/j.pestbp.2017.09.012
    The evolution of weed-resistant species threatens the sustainable use of glyphosate, which is the most important herbicide widely used in agriculture worldwide. Moreover, the high glyphosate resistance (>180-fold based on LD50) of Eleusine indica found in Malaysia, which carries a double mutation in its 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), made the control of this species more difficult. By contrast, the same species carrying the same double mutation in EPSPS (T102I+P106S) but found in China only shows a resistance level of not more than 14-fold based on GR50. The resistance level of this population is four times higher than that of the population carrying a single mutation (P106L). Although the members of this population survive under a high glyphosate dosage of 10,080gaeha-1, their growth was significantly inhibited by glyphosate under the recommend dose (840gaeha-1), where in the fresh weight was 85.4% of the control. EPSPS expression, relative copy number, and EPSPS activity in this population were similar to those of the susceptible population. In addition, the expression of two glutathione transferase (GST) genes (GST-U8 and GST-23) and the enzyme activity of the GST in this population did not significantly differ from those of the susceptible population. This finding is important in elucidating the resistance of the naturally evolved glyphosate-resistant (GR) weed species carrying a double mutation in EPSPS to glyphosate.
    Matched MeSH terms: Plant Proteins/metabolism
  7. Wong GR, Mazumdar P, Lau SE, Harikrishna JA
    J Plant Physiol, 2018 Dec;231:219-233.
    PMID: 30292098 DOI: 10.1016/j.jplph.2018.09.018
    Genetic improvement is an important approach for crop improvement towards yield stability in stress-prone areas. Functional analysis of candidate stress response genes can provide key information to allow the selection and modification of improved crop varieties. In this study, the constitutive expression of a banana cDNA, MaRHD3 in Arabidopsis improved the ability of transgenic lines to adapt to drought conditions. Transgenic Arabidopsis plants expressing MaRHD3 had roots with enhanced branching and more root hairs when challenged with drought stress. The MaRHD3 plants had higher biomass accumulation, higher relative water content, higher chlorophyll content and an increase in activity of reactive oxygen species (ROS) scavenging enzymes; SOD, CAT, GR, POD and APX with reduced water loss rates compared to control plants. The analysis of oxidative damage indicated lower cell membrane damage in transgenic lines compared to control plants. These findings, together with data from higher expression of ABF-3 and higher ABA content of drought-stressed transgenic MaRHD3 expressing plants, support the involvement of the ABA signal pathway and ROS scavenging enzyme systems in MaRHD3 mediated drought tolerance.
    Matched MeSH terms: Plant Proteins/metabolism
  8. Tan YC, Yeoh KA, Wong MY, Ho CL
    J Plant Physiol, 2013 Nov 01;170(16):1455-60.
    PMID: 23769496 DOI: 10.1016/j.jplph.2013.05.009
    Basal stem rot (BSR) is a major disease of oil palm caused by a pathogenic fungus, Ganoderma boninense. However, the interaction between the host plant and its pathogen is not well characterized. To better understand the response of oil palm to G. boninense, transcript profiles of eleven putative defence-related genes from oil palm were measured by quantitative reverse-transcription (qRT)-PCR in the roots of oil palms treated with G. boninense from 3 to 12 weeks post infection (wpi). These transcripts encode putative Bowman-Birk serine protease inhibitors (EgBBI1 and 2), defensin (EgDFS), dehydrin (EgDHN), early methionine-labeled polypeptides (EgEMLP1 and 2), glycine-rich RNA binding protein (EgGRRBP), isoflavone reductase (EgIFR), metallothionein-like protein (EgMT), pathogenesis-related-1 protein (EgPRP), and type 2 ribosome-inactivating protein (EgT2RIP). The transcript abundance of EgBBI2 increased in G. boninense-treated roots at 3 and 6wpi compared to those of controls; while the transcript abundance of EgBBI1, EgDFS, EgEMLP1, EgMT, and EgT2RIP increased in G. boninense-treated roots at 6 or 12wpi. Meanwhile, the gene expression of EgDHN was up-regulated at all three time points in G. boninense-treated roots. The expression profiles of the eleven transcripts were also studied in leaf samples upon inoculation of G. boninense and Trichoderma harzianum to identify potential biomarkers for early detection of BSR. Two candidate genes (EgEMLP1 and EgMT) that have different profiles in G. boninense-treated leaves compared to those infected by T. harzianum may have the potential to be developed as biomarkers for early detection of G. boninense infection.
    Matched MeSH terms: Plant Proteins/metabolism
  9. Brennan M, Paterson L, Baharudin AAA, Stanisz-Migal M, Hoebe PN
    J Plant Physiol, 2019 Dec;243:153054.
    PMID: 31648109 DOI: 10.1016/j.jplph.2019.153054
    Adhesion of the barley husk to the underlying caryopsis requires the development of a cuticular cementing layer on the caryopsis surface. Differences in adhesion quality among genotypes have previously been correlated with cementing layer composition, which is thought to influence caryopsis cuticle permeability, the hypothesised mechanism of adhesion mediation. It is not yet known whether differences in adhesion quality among genotypes are determined by changes in caryopsis cuticle permeability. We examined changes in candidate cementing layer biosynthetic and regulatory genes to investigate the genetic mechanisms behind husk adhesion quality. We used both commercially relevant UK malting cultivars and older European lines to ensure phenotypic diversity in adhesion quality. An ethylene responsive transcription factor (NUD) is required for the development of the cementing layer. To examine correlations between gene expression, cementing layer permeability and husk adhesion quality we also treated cultivars with ethephon (2-chloroethylphosphonic acid) which breaks down to ethylene, and silver thiosulphate which inhibits ethylene reception, and measured caryopsis cuticle permeability. Differential adhesion qualities among genotypes are not determined by NUD expression during development of the cementing material alone, but could result from differences in biosynthetic gene expression during cementing layer development in response to longer-term NUD expression patterns. Altered caryopsis cuticle permeability does result in altered adhesion quality, but the correlation is not consistently positive or negative. Cuticle permeability is therefore not the mechanism that determines husk adhesion quality, but is likely a consequence of the required cuticular compositional changes that determine adhesion.
    Matched MeSH terms: Plant Proteins/metabolism
  10. Yeap WC, Lee FC, Shabari Shan DK, Musa H, Appleton DR, Kulaveerasingam H
    Plant J, 2017 Jul;91(1):97-113.
    PMID: 28370622 DOI: 10.1111/tpj.13549
    The oil biosynthesis pathway must be tightly controlled to maximize oil yield. Oil palm accumulates exceptionally high oil content in its mesocarp, suggesting the existence of a unique fruit-specific fatty acid metabolism transcriptional network. We report the complex fruit-specific network of transcription factors responsible for modulation of oil biosynthesis genes in oil palm mesocarp. Transcriptional activation of EgWRI1-1 encoding a key master regulator that activates expression of oil biosynthesis genes, is activated by three ABA-responsive transcription factors, EgNF-YA3, EgNF-YC2 and EgABI5. Overexpression of EgWRI1-1 and its activators in Arabidopsis accelerated flowering, increased seed size and oil content, and altered expression levels of oil biosynthesis genes. Protein-protein interaction experiments demonstrated that EgNF-YA3 interacts directly with EgWRI1-1, forming a transcription complex with EgNF-YC2 and EgABI5 to modulate transcription of oil biosynthesis pathway genes. Furthermore, EgABI5 acts downstream of EgWRKY40, a repressor that interacts with EgWRKY2 to inhibit the transcription of oil biosynthesis genes. We showed that expression of these activators and repressors in oil biosynthesis can be induced by phytohormones coordinating fruit development in oil palm. We propose a model highlighting a hormone signaling network coordinating fruit development and fatty acid biosynthesis.
    Matched MeSH terms: Plant Proteins/metabolism
  11. Heskes AM, Sundram TCM, Boughton BA, Jensen NB, Hansen NL, Crocoll C, et al.
    Plant J, 2018 03;93(5):943-958.
    PMID: 29315936 DOI: 10.1111/tpj.13822
    Vitex agnus-castus L. (Lamiaceae) is a medicinal plant historically used throughout the Mediterranean region to treat menstrual cycle disorders, and is still used today as a clinically effective treatment for premenstrual syndrome. The pharmaceutical activity of the plant extract is linked to its ability to lower prolactin levels. This feature has been attributed to the presence of dopaminergic diterpenoids that can bind to dopamine receptors in the pituitary gland. Phytochemical analyses of V. agnus-castus show that it contains an enormous array of structurally related diterpenoids and, as such, holds potential as a rich source of new dopaminergic drugs. The present work investigated the localisation and biosynthesis of diterpenoids in V. agnus-castus. With the assistance of matrix-assisted laser desorption ionisation-mass spectrometry imaging (MALDI-MSI), diterpenoids were localised to trichomes on the surface of fruit and leaves. Analysis of a trichome-specific transcriptome database, coupled with expression studies, identified seven candidate genes involved in diterpenoid biosynthesis: three class II diterpene synthases (diTPSs); three class I diTPSs; and a cytochrome P450 (CYP). Combinatorial assays of the diTPSs resulted in the formation of a range of different diterpenes that can account for several of the backbones of bioactive diterpenoids observed in V. agnus-castus. The identified CYP, VacCYP76BK1, was found to catalyse 16-hydroxylation of the diol-diterpene, peregrinol, to labd-13Z-ene-9,15,16-triol when expressed in Saccharomyces cerevisiae. Notably, this product is a potential intermediate in the biosynthetic pathway towards bioactive furan- and lactone-containing diterpenoids that are present in this species.
    Matched MeSH terms: Plant Proteins/metabolism*
  12. Tiwari GJ, Liu Q, Shreshtha P, Li Z, Rahman S
    BMC Plant Biol, 2016 08 31;16(1):189.
    PMID: 27581494 DOI: 10.1186/s12870-016-0881-6
    BACKGROUND: The bran from polished rice grains can be used to produce rice bran oil (RBO). High oleic (HO) RBO has been generated previously through RNAi down-regulation of OsFAD2-1. HO-RBO has higher oxidative stability and could be directly used in the food industry without hydrogenation, and is hence free of trans fatty acids. However, relative to a classic oilseed, lipid metabolism in the rice grain is poorly studied and the genetic alteration in the novel HO genotype remains unexplored.

    RESULTS: Here, we have undertaken further analysis of role of OsFAD2-1 in the developing rice grain. The use of Illumina-based NGS transcriptomics analysis of developing rice grain reveals that knockdown of Os-FAD2-1 gene expression was accompanied by the down regulation of the expression of a number of key genes in the lipid biosynthesis pathway in the HO rice line. A slightly higher level of oil accumulation was also observed in the HO-RBO.

    CONCLUSION: Prominent among the down regulated genes were those that coded for FatA, LACS, SAD2, SAD5, caleosin and steroleosin. It may be possible to further increase the oleic acid content in rice oil by altering the expression of the lipid biosynthetic genes that are affected in the HO line.

    Matched MeSH terms: Plant Proteins/metabolism
  13. Ee SF, Mohamed-Hussein ZA, Othman R, Shaharuddin NA, Ismail I, Zainal Z
    ScientificWorldJournal, 2014;2014:840592.
    PMID: 24678279 DOI: 10.1155/2014/840592
    Polygonum minus is an aromatic plant, which contains high abundance of terpenoids, especially the sesquiterpenes C15H24. Sesquiterpenes were believed to contribute to the many useful biological properties in plants. This study aimed to functionally characterize a full length sesquiterpene synthase gene from P. minus. P. minus sesquiterpene synthase (PmSTS) has a complete open reading frame (ORF) of 1689 base pairs encoding a 562 amino acid protein. Similar to other sesquiterpene synthases, PmSTS has two large domains: the N-terminal domain and the C-terminal metal-binding domain. It also consists of three conserved motifs: the DDXXD, NSE/DTE, and RXR. A three-dimensional protein model for PmSTS built clearly distinguished the two main domains, where conserved motifs were highlighted. We also constructed a phylogenetic tree, which showed that PmSTS belongs to the angiosperm sesquiterpene synthase subfamily Tps-a. To examine the function of PmSTS, we expressed this gene in Arabidopsis thaliana. Two transgenic lines, designated as OE3 and OE7, were further characterized, both molecularly and functionally. The transgenic plants demonstrated smaller basal rosette leaves, shorter and fewer flowering stems, and fewer seeds compared to wild type plants. Gas chromatography-mass spectrometry analysis of the transgenic plants showed that PmSTS was responsible for the production of β -sesquiphellandrene.
    Matched MeSH terms: Plant Proteins/metabolism*
  14. Hakim MA, Juraimi AS, Hanafi MM, Ismail MR, Selamat A, Rafii MY, et al.
    Biomed Res Int, 2014;2014:208584.
    PMID: 24579076 DOI: 10.1155/2014/208584
    Five Malaysian rice (Oryza sativa L.) varieties, MR33, MR52, MR211, MR219, and MR232, were tested in pot culture under different salinity regimes for biochemical response, physiological activity, and grain yield. Three different levels of salt stresses, namely, 4, 8, and 12 dS m(-1), were used in a randomized complete block design with four replications under glass house conditions. The results revealed that the chlorophyll content, proline, sugar content, soluble protein, free amino acid, and yield per plant of all the genotypes were influenced by different salinity levels. The chlorophyll content was observed to decrease with salinity level but the proline increased with salinity levels in all varieties. Reducing sugar and total sugar increased up to 8 dS m(-1) and decreased up to 12 dS m(-1). Nonreducing sugar decreased with increasing the salinity levels in all varieties. Soluble protein and free amino acid also decreased with increasing salinity levels. Cortical cells of MR211 and MR232 did not show cell collapse up to 8 dS m(-1) salinity levels compared to susceptible checks (IR20 and BRRI dhan29). Therefore, considering all parameters, MR211 and MR232 showed better salinity tolerance among the tested varieties. Both cluster and principal component analyses depict the similar results.
    Matched MeSH terms: Plant Proteins/metabolism
  15. Al-Obaidi JR, Mohd-Yusuf Y, Razali N, Jayapalan JJ, Tey CC, Md-Noh N, et al.
    Int J Mol Sci, 2014;15(3):5175-92.
    PMID: 24663087 DOI: 10.3390/ijms15035175
    Basal stem rot is a common disease that affects oil palm, causing loss of yield and finally killing the trees. The disease, caused by fungus Ganoderma boninense, devastates thousands of hectares of oil palm plantings in Southeast Asia every year. In the present study, root proteins of healthy oil palm seedlings, and those infected with G. boninense, were analyzed by 2-dimensional gel electrophoresis (2-DE). When the 2-DE profiles were analyzed for proteins, which exhibit consistent significant change of abundance upon infection with G. boninense, 21 passed our screening criteria. Subsequent analyses by mass spectrometry and database search identified caffeoyl-CoA O-methyltransferase, caffeic acid O-methyltransferase, enolase, fructokinase, cysteine synthase, malate dehydrogenase, and ATP synthase as among proteins of which abundances were markedly altered.
    Matched MeSH terms: Plant Proteins/metabolism*
  16. Cha TS, Najihah MG, Sahid IB, Chuah TS
    Pestic Biochem Physiol, 2014 May;111:7-13.
    PMID: 24861927 DOI: 10.1016/j.pestbp.2014.04.011
    Eleusine indica (goosegrass) populations resistant to fluazifop, an acetyl-CoA carboxylase (ACCase: EC6.4.1.2)-inhibiting herbicide, were found in several states in Malaysia. Dose-response assay indicated a resistance factor of 87.5, 62.5 and 150 for biotypes P2, P3 and P4, respectively. DNA sequencing and allele-specific PCR revealed that both biotypes P2 and P3 exhibit a single non-synonymous point mutation from TGG to TGC that leads to a well known Trp-2027-Cys mutation. Interestingly, the highly resistant biotype, P4, did not contain any of the known mutation except the newly discovered target point Asn-2097-Asp, which resulted from a nucleotide change in the codon AAT to GAT. ACCase gene expression was found differentially regulated in the susceptible biotype (P1) and highly resistant biotype P4 from 24 to 72h after treatment (HAT) when being treated with the recommended field rate (198gha(-1)) of fluazifop. However, the small and erratic differences of ACCase gene expression between biotype P1 and P4 does not support the 150-fold resistance in biotype P4. Therefore, the involvement of the target point Asn-2097-Asp and other non-target-site-based resistance mechanisms in the biotype P4 could not be ruled out.
    Matched MeSH terms: Plant Proteins/metabolism
  17. Omidvar V, Abdullah SN, Ho CL, Mahmood M, Al-Shanfari AB
    Mol Biol Rep, 2012 Sep;39(9):8907-18.
    PMID: 22722992 DOI: 10.1007/s11033-012-1758-x
    Abscisic acid (ABA) is an important phytohormone involved in the abiotic stress resistance in plants. The ABA-responsive element (ABRE) binding factors play significant roles in the plant development and response to abiotic stresses, but none so far have been isolated and characterized from the oil palm. Two ABA-responsive cDNA clones, named EABF and EABF1, were isolated from the oil palm fruits using yeast one-hybrid system. The EABF had a conserved AP2/EREBP DNA-binding domain (DNA-BD) and a potential nuclear localization sequence (NLS). No previously known DNA-BD was identified from the EABF1 sequence. The EABF and EABF1 proteins were classified as DREB/CBF and bZIP family members based on the multiple sequence alignment and phylogenetic analysis. Both proteins showed ABRE-binding and transcriptional activation properties in yeast. Furthermore, both proteins were able to trans-activate the down-stream expression of the LacZ reporter gene in yeast. An electrophoretic mobility shift assay revealed that in addition to the ABRE sequence, both proteins could bind to the DRE sequence as well. Transcriptional analysis revealed that the expression of EABF was induced in response to the ABA in the oil palm fruits and leaves, but not in roots, while the EABF1 was constitutively induced in all tissues. The expressions of both genes were strongly induced in fruits in response to the ABA, ethylene, methyl jasmonate, drought, cold and high-salinity treatments, indicating that the EABF and EABF1 might act as connectors among different stress signal transduction pathways. Our results indicate that the EABF and EABF1 are novel stress-responsive transcription factors, which are involved in the abiotic stress response and ABA signaling in the oil palm and could be used for production of stress-tolerant transgenic crops.
    Matched MeSH terms: Plant Proteins/metabolism*
  18. Zakaria II, Rahman RN, Salleh AB, Basri M
    Appl Biochem Biotechnol, 2011 Sep;165(2):737-47.
    PMID: 21633820 DOI: 10.1007/s12010-011-9292-1
    Flavonoids are secondary metabolites synthesized by plants shown to exhibit health benefits such as anti-inflammatory, antioxidant, and anti-tumor effects. Thus, due to the importance of this compound, several enzymes involved in the flavonoid pathway have been cloned and characterized in Escherichia coli. However, the formation of inclusion bodies has become a major disadvantage of this approach. As an alternative, chalcone synthase from Physcomitrella patens was secreted into the medium using a bacteriocin release protein expression vector. Secretion of P. patens chalcone synthase into the culture media was achieved by co-expression with a psW1 plasmid encoding bacteriocin release protein in E. coli Tuner (DE3) plysS. The optimized conditions, which include the incubation of cells for 20 h with 40 ng/ml mitomycin C at OD(600) induction time of 0.5 was found to be the best condition for chalcone synthase secretion.
    Matched MeSH terms: Plant Proteins/metabolism*
  19. Ibrahim MH, Jaafar HZ, Rahmat A, Rahman ZA
    Int J Mol Sci, 2011;12(8):5238-54.
    PMID: 21954355 DOI: 10.3390/ijms12085238
    A split plot 3 by 4 experiment was designed to examine the impact of 15-week variable levels of nitrogen fertilization (0, 90, 180 and 270 kg N/ha) on the characteristics of total flavonoids (TF), total phenolics (TP), total non structurable carbohydrate (TNC), net assimilation rate, leaf chlorophyll content, carbon to nitrogen ratio (C/N), phenyl alanine lyase activity (PAL) and protein content, and their relationships, in three varieties of Labisia pumila Blume (alata, pumila and lanceolata). The treatment effects were solely contributed by nitrogen application; there was neither varietal nor interaction effect observed. As nitrogen levels increased from 0 to 270 kg N/ha, the production of TNC was found to decrease steadily. Production of TF and TP reached their peaks under 0 followed by 90, 180 and 270 kg N/ha treatment. However, net assimilation rate was enhanced as nitrogen fertilization increased from 0 to 270 kg N/ha. The increase in production of TP and TF under low nitrogen levels (0 and 90 kg N/ha) was found to be correlated with enhanced PAL activity. The enhancement in PAL activity was followed by reduction in production of soluble protein under low nitrogen fertilization indicating more availability of amino acid phenyl alanine (phe) under low nitrogen content that stimulate the production of carbon based secondary metabolites (CBSM). The latter was manifested by high C/N ratio in L. pumila plants.
    Matched MeSH terms: Plant Proteins/metabolism
  20. Teh OK, Ramli US
    Mol Biotechnol, 2011 Jun;48(2):97-108.
    PMID: 21113689 DOI: 10.1007/s12033-010-9350-x
    As the world population grows, the demand for food increases. Although vegetable oils provide an affordable and rich source of energy, the supply of vegetable oils available for human consumption is limited by the "fuel vs food" debate. To increase the nutritional value of vegetable oil, metabolic engineering may be used to produce oil crops of desirable fatty acid composition. We have isolated and characterized β-ketoacyl ACP-synthase II (KASII) cDNA from a high-oleic acid palm, Jessenia bataua. Jessenia KASII (JbKASII) encodes a 488-amino acid polypeptide that possesses conserved domains that are necessary for condensing activities. When overexpressed in E. coli, recombinant His-tagged JbKASII was insoluble and non-functional. However, Arabidopsis plants expressing GFP-JbKASII fusions had elevated levels of arachidic acid (C20:0) and erucic acid (C22:1) at the expense of stearic acid (C18:0) and oleic acid (C18:1). Furthermore, JbKASII failed to complement the Arabidopsis KASII mutant, fab1-2. This suggests that the substrate specificity of JbKASII is similar to that of ketoacyl-CoA synthase (KCS), which preferentially elongates stearic and oleic acids, and not palmitic acid. Our results suggest that the KCS-like JbKASII may elongate C18:0 and C18:1 to yield C20:0 and C22:1, respectively. JbKASII may, therefore, be an interesting candidate gene for promoting the production of very long chain fatty acids in transgenic oil crops.
    Matched MeSH terms: Plant Proteins/metabolism*
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