Displaying publications 21 - 40 of 91 in total

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  1. Song BK, Hein I, Druka A, Waugh R, Marshall D, Nadarajah K, et al.
    Funct Integr Genomics, 2009 Feb;9(1):97-108.
    PMID: 18633654 DOI: 10.1007/s10142-008-0091-x
    Common wild rice (Oryza rufipogon) plays an important role by contributing to modern rice breeding. In this paper, we report the sequence and analysis of a 172-kb genomic DNA region of wild rice around the RM5 locus, which is associated with the yield QTL yld1.1. Comparative sequence analysis between orthologous RM5 regions from Oryza sativa ssp. japonica, O. sativa ssp. indica and O. rufipogon revealed a high level of conserved synteny in the content, homology, structure, orientation, and physical distance of all 14 predicted genes. Twelve of the putative genes were supported by matches to proteins with known function, whereas two were predicted by homology to rice and other plant expressed sequence tags or complementary DNAs. The remarkably high level of conservation found in coding, intronic and intergenic regions may indicate high evolutionary selection on the RM5 region. Although our analysis has not defined which gene(s) determine the yld1.1 phenotype, allelic variation and the insertion of transposable elements, among other nucleotide changes, represent potential variation responsible for the yield QTL. However, as suggested previously, two putative receptor-like protein kinase genes remain the key suspects for yld1.1.
    Matched MeSH terms: Genes, Plant
  2. Cui Y, Song BK, Li LF, Li YL, Huang Z, Caicedo AL, et al.
    G3 (Bethesda), 2016 Dec 07;6(12):4105-4114.
    PMID: 27729434 DOI: 10.1534/g3.116.035881
    Weedy rice is a conspecific form of cultivated rice (Oryza sativa L.) that infests rice fields and results in severe crop losses. Weed strains in different world regions appear to have originated multiple times from different domesticated and/or wild rice progenitors. In the case of Malaysian weedy rice, a multiple-origin model has been proposed based on neutral markers and analyses of domestication genes for hull color and seed shattering. Here, we examined variation in pericarp (bran) color and its molecular basis to address how this trait evolved in Malaysian weeds and its possible role in weed adaptation. Functional alleles of the Rc gene confer proanthocyanidin pigmentation of the pericarp, a trait found in most wild and weedy Oryzas and associated with seed dormancy; nonfunctional rc alleles were strongly favored during rice domestication, and most cultivated varieties have nonpigmented pericarps. Phenotypic characterizations of 52 Malaysian weeds revealed that most strains are characterized by the pigmented pericarp; however, some weeds have white pericarps, suggesting close relationships to cultivated rice. Phylogenetic analyses indicate that the Rc haplotypes present in Malaysian weeds likely have at least three distinct origins: wild O. rufipogon, white-pericarp cultivated rice, and red-pericarp cultivated rice. These diverse origins contribute to high Rc nucleotide diversity in the Malaysian weeds. Comparison of Rc allelic distributions with other rice domestication genes suggests that functional Rc alleles may confer particular fitness benefits in weedy rice populations, for example, by conferring seed dormancy. This may promote functional Rc introgression from local wild Oryza populations.
    Matched MeSH terms: Genes, Plant
  3. Golestan Hashemi FS, Rafii MY, Ismail MR, Mohamed MT, Rahim HA, Latif MA, et al.
    Gene, 2015 Jan 25;555(2):101-7.
    PMID: 25445269 DOI: 10.1016/j.gene.2014.10.048
    MRQ74, a popular aromatic Malaysian landrace, allows for charging considerably higher prices than non-aromatic landraces. Thus, breeding this profitable trait has become a priority for Malaysian rice breeding. Despite many studies on aroma genetics, ambiguities considering its genetic basis remain. It has been observed that identifying quantitative trait loci (QTLs) based on anchor markers, particularly candidate genes controlling a trait of interest, can increase the power of QTL detection. Hence, this study aimed to locate QTLs that influence natural variations in rice scent using microsatellites and candidate gene-based sequence polymorphisms. For this purpose, an F2 mapping population including 189 individual plants was developed by MRQ74 crosses with 'MR84', a non-scented Malaysian accession. Additionally, qualitative and quantitative approaches were applied to obtain a phenotype data framework. Consequently, we identified two QTLs on chromosomes 4 and 8. These QTLs explained from 3.2% to 39.3% of the total fragrance phenotypic variance. In addition, we could resolve linkage group 8 by adding six gene-based primers in the interval harboring the most robust QTL. Hence, we could locate a putative fgr allele in the QTL found on chromosome 8 in the interval RM223-SCU015RM (1.63cM). The identified QTLs represent an important step toward recognition of the rice flavor genetic control mechanism. In addition, this identification will likely accelerate the progress of the use of molecular markers for gene isolation, gene-based cloning, and marker-assisted selection breeding programs aimed at improving rice cultivars.
    Matched MeSH terms: Genes, Plant
  4. Ngu MS, Thomson MJ, Bhuiyan MA, Ho C, Wickneswari R
    Genet. Mol. Res., 2014;13(4):9477-88.
    PMID: 25501158 DOI: 10.4238/2014.November.11.13
    Grain weight is a major component of rice grain yield and is controlled by quantitative trait loci. Previously, a rice grain weight quantitative trait locus (qGW6) was detected near marker RM587 on chromosome 6 in a backcross population (BC2F2) derived from a cross between Oryza rufipogon IRGC105491 and O. sativa cv. MR219. Using a BC2F5 population, qGW6 was validated and mapped to a region of 4.8 cM (1.2 Mb) in the interval between RM508 and RM588. Fine mapping using a series of BC4F3 near isogenic lines further narrowed the interval containing qGW6 to 88 kb between markers RM19268 and RM19271.1. According to the Duncan multiple range test, 8 BC4F4 near isogenic lines had significantly higher 100-grain weight (4.8 to 7.5% over MR219) than their recurrent parent, MR219 (P < 0.05). According to the rice genome automated annotation database, there are 20 predicted genes in the 88-kb target region, and 9 of them have known functions. Among the genes with known functions in the target region, in silico gene expression analysis showed that 9 were differentially expressed during the seed development stage(s) from gene expression series GSE6893; however, only 3 of them have known functions. These candidates provide targets for further characterization of qGW6, which will assist in understanding the genetic control of grain weight in rice.
    Matched MeSH terms: Genes, Plant
  5. Ng CY, Wickneswari R, Choong CY
    Genet. Mol. Res., 2014;13(3):6037-49.
    PMID: 25117361 DOI: 10.4238/2014.August.7.18
    Calamus palustris Griff. is an economically important dioecious rattan species in Southeast Asia. However, dioecy and onset of flowering at 3-4 years old render uncertainties in desired female:male seedling ratios to establish a productive seed orchard for this rattan species. We constructed a subtractive library for male floral tissue to understand the genetic mechanism for gender determination in C. palustris. The subtractive library produced 1536 clones with 1419 clones of high quality. Reverse Northern screening showed 313 clones with differential expression, and sequence analyses clustered them into 205 unigenes, including 32 contigs and 173 singletons. The subtractive library was further validated with reverse transcription-quantitative polymerase chain reaction analysis. Homology identification classified the unigenes into 12 putative functional proteins with 83% unigenes showing significant match to proteins in databases. Functional annotations of these unigenes revealed genes involved in male flower development, including MADS-box genes, pollen-related genes, phytohormones for flower development, and male flower organ development. Our results showed that the male floral genes may play a vital role in sex determination in C. palustris. The identified genes can be exploited to understand the molecular basis of sex determination in C. palustris.
    Matched MeSH terms: Genes, Plant*
  6. Hasan N, Rafii MY, Abdul Rahim H, Nusaibah SA, Mazlan N, Abdullah S
    Genet. Mol. Res., 2017 Jan 23;16(1).
    PMID: 28128411 DOI: 10.4238/gmr16019280
    Rice (Oryza sativa L.) blast disease is one of the most destructive rice diseases in the world. The fungal pathogen, Magnaporthe oryzae, is the causal agent of rice blast disease. Development of resistant cultivars is the most preferred method to achieve sustainable rice production. However, the effectiveness of resistant cultivars is hindered by the genetic plasticity of the pathogen genome. Therefore, information on genetic resistance and virulence stability are vital to increase our understanding of the molecular basis of blast disease resistance. The present study set out to elucidate the resistance pattern and identify potential simple sequence repeat markers linked with rice blast disease. A backcross population (BC2F1), derived from crossing MR264 and Pongsu Seribu 2 (PS2), was developed using marker-assisted backcross breeding. Twelve microsatellite markers carrying the blast resistance gene clearly demonstrated a polymorphic pattern between both parental lines. Among these, two markers, RM206 and RM5961, located on chromosome 11 exhibited the expected 1:1 testcross ratio in the BC2F1 population. The 195 BC2F1 plants inoculated against M. oryzae pathotype P7.2 showed a significantly different distribution in the backcrossed generation and followed Mendelian segregation based on a single-gene model. This indicates that blast resistance in PS2 is governed by a single dominant gene, which is linked to RM206 and RM5961 on chromosome 11. The findings presented in this study could be useful for future blast resistance studies in rice breeding programs.
    Matched MeSH terms: Genes, Plant*
  7. Cheng A, Ismail I, Osman M, Hashim H, Mohd Zainual NS
    Genome, 2017 Dec;60(12):1045-1050.
    PMID: 28813631 DOI: 10.1139/gen-2017-0100
    While it is crucial for developing countries like Malaysia to achieve self-sufficiency in rice (Oryza sativa L.), it is equally critical to be able to produce high-quality rice, specifically fragrant rice, which demands are often met through importation. The present study was aimed at developing high-yielding fragrant rice, in a timely and cost-effective manner. A marker-assisted backcross (MABC) approach was optimised to introgress the fragrance gene (fgr) into two high-yielding Malaysian varieties, MR84 and MR219, within two years utilising less than 50 molecular markers. Coupled with phenotypic screening, one single foreground marker (fgr-SNP) and 48 background markers were selected and utilised, revealing recovery of at least 90% of recurrent parent genome (RPG) in merely two backcross generations. Collectively, the yield potential of the developed BC2F2 lines (BLs) was higher (P > 0.05) than the donor parent, MRQ74, and similar (P < 0.05) to both the recurrent parents, MR84 and MR219. In addition, some of the developed BLs showed good grain quality, such as having long grain. We believe that this is the first report comprising the validation and utilisation of the single functional marker system (fgr-SNP) in introgressing the fgr gene into different rice varieties.
    Matched MeSH terms: Genes, Plant
  8. Chang Y, Liu H, Liu M, Liao X, Sahu SK, Fu Y, et al.
    Gigascience, 2019 03 01;8(3).
    PMID: 30535374 DOI: 10.1093/gigascience/giy152
    BACKGROUND: The expanding world population is expected to double the worldwide demand for food by 2050. Eighty-eight percent of countries currently face a serious burden of malnutrition, especially in Africa and south and southeast Asia. About 95% of the food energy needs of humans are fulfilled by just 30 species, of which wheat, maize, and rice provide the majority of calories. Therefore, to diversify and stabilize the global food supply, enhance agricultural productivity, and tackle malnutrition, greater use of neglected or underutilized local plants (so-called orphan crops, but also including a few plants of special significance to agriculture, agroforestry, and nutrition) could be a partial solution.

    RESULTS: Here, we present draft genome information for five agriculturally, biologically, medicinally, and economically important underutilized plants native to Africa: Vigna subterranea, Lablab purpureus, Faidherbia albida, Sclerocarya birrea, and Moringa oleifera. Assembled genomes range in size from 217 to 654 Mb. In V. subterranea, L. purpureus, F. albida, S. birrea, and M. oleifera, we have predicted 31,707, 20,946, 28,979, 18,937, and 18,451 protein-coding genes, respectively. By further analyzing the expansion and contraction of selected gene families, we have characterized root nodule symbiosis genes, transcription factors, and starch biosynthesis-related genes in these genomes.

    CONCLUSIONS: These genome data will be useful to identify and characterize agronomically important genes and understand their modes of action, enabling genomics-based, evolutionary studies, and breeding strategies to design faster, more focused, and predictable crop improvement programs.

    Matched MeSH terms: Genes, Plant
  9. Harada K, Kinoshita A, Shukor NA, Tachida H, Yamazaki T
    Jpn. J. Genet., 1994 Dec;69(6):713-8.
    PMID: 7857675
    Three species of Shorea (S. leprosula, S. acuminata and S. cursitii) were collected from a natural forest reserve of Malaysia and analyzed for genetic variation using the technique of random amplification of polymorphic DNA (RAPD) by the polymerase chain reaction (PCR). The average number of nucleotide substitutions was estimated. The nucleotide diversities within species were very similar and larger than those found in Drosophila melanogaster. The nucleotide divergences between these species are about 1.5 times the nucleotide diversities within the species, indicating that these species diverged from a common ancestor relatively recently.
    Matched MeSH terms: Genes, Plant
  10. Roslan ND, Yusop JM, Baharum SN, Othman R, Mohamed-Hussein ZA, Ismail I, et al.
    Int J Mol Sci, 2012;13(3):2692-706.
    PMID: 22489118 DOI: 10.3390/ijms13032692
    P. minus is an aromatic plant, the leaf of which is widely used as a food additive and in the perfume industry. The leaf also accumulates secondary metabolites that act as active ingredients such as flavonoid. Due to limited genomic and transcriptomic data, the biosynthetic pathway of flavonoids is currently unclear. Identification of candidate genes involved in the flavonoid biosynthetic pathway will significantly contribute to understanding the biosynthesis of active compounds. We have constructed a standard cDNA library from P. minus leaves, and two normalized full-length enriched cDNA libraries were constructed from stem and root organs in order to create a gene resource for the biosynthesis of secondary metabolites, especially flavonoid biosynthesis. Thus, large-scale sequencing of P. minus cDNA libraries identified 4196 expressed sequences tags (ESTs) which were deposited in dbEST in the National Center of Biotechnology Information (NCBI). From the three constructed cDNA libraries, 11 ESTs encoding seven genes were mapped to the flavonoid biosynthetic pathway. Finally, three flavonoid biosynthetic pathway-related ESTs chalcone synthase, CHS (JG745304), flavonol synthase, FLS (JG705819) and leucoanthocyanidin dioxygenase, LDOX (JG745247) were selected for further examination by quantitative RT-PCR (qRT-PCR) in different P. minus organs. Expression was detected in leaf, stem and root. Gene expression studies have been initiated in order to better understand the underlying physiological processes.
    Matched MeSH terms: Genes, Plant
  11. Song AA, Abdullah JO, Abdullah MP, Shafee N, Rahim RA
    Int J Mol Sci, 2012;13(2):1582-97.
    PMID: 22408409 DOI: 10.3390/ijms13021582
    Vanda Mimi Palmer (VMP), an orchid hybrid of Vanda tesselata and Vanda Tan Chay Yan is a highly scented tropical orchid which blooms all year round. Previous studies revealed that VMP produces a variety of isoprenoid volatiles during daylight. Isoprenoids are well known to contribute significantly to the scent of most fragrant plants. They are a large group of secondary metabolites which may possess valuable characteristics such as flavor, fragrance and toxicity and are produced via two pathways, the mevalonate (MVA) pathway or/and the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway. In this study, a sesquiterpene synthase gene denoted VMPSTS, previously isolated from a floral cDNA library of VMP was cloned and expressed in Lactococcus lactis to characterize the functionality of the protein. L. lactis, a food grade bacterium which utilizes the mevalonate pathway for isoprenoid production was found to be a suitable host for the characterization of plant terpene synthases. Through recombinant expression of VMPSTS, it was revealed that VMPSTS produced multiple sesquiterpenes and germacrene D dominates its profile.
    Matched MeSH terms: Genes, Plant*
  12. Zimisuhara B, Valdiani A, Shaharuddin NA, Qamaruzzaman F, Maziah M
    Int J Mol Sci, 2015 Jun 24;16(7):14369-94.
    PMID: 26114389 DOI: 10.3390/ijms160714369
    Genetic structure and biodiversity of the medicinal plant Ficus deltoidea have rarely been scrutinized. To fill these lacunae, five varieties, consisting of 30 F. deltoidea accessions were collected across the country and studied on the basis of molecular and morphological data. Molecular analysis of the accessions was performed using nine Inter Simple Sequence Repeat (ISSR) markers, seven of which were detected as polymorphic markers. ISSR-based clustering generated four clusters supporting the geographical distribution of the accessions to some extent. The Jaccard's similarity coefficient implied the existence of low diversity (0.50-0.75) in the studied population. STRUCTURE analysis showed a low differentiation among the sampling sites, while a moderate varietal differentiation was unveiled with two main populations of F. deltoidea. Our observations confirmed the occurrence of gene flow among the accessions; however, the highest degree of this genetic interference was related to the three accessions of FDDJ10, FDTT16 and FDKT25. These three accessions may be the genetic intervarietal fusion points of the plant's population. Principal Components Analysis (PCA) relying on quantitative morphological characteristics resulted in two principal components with Eigenvalue >1 which made up 89.96% of the total variation. The cluster analysis performed by the eight quantitative characteristics led to grouping the accessions into four clusters with a Euclidean distance ranged between 0.06 and 1.10. Similarly, a four-cluster dendrogram was generated using qualitative traits. The qualitative characteristics were found to be more discriminating in the cluster and PCA analyses, while ISSRs were more informative on the evolution and genetic structure of the population.
    Matched MeSH terms: Genes, Plant
  13. Zhu W, Zhong Z, Liu S, Yang B, Komatsu S, Ge Z, et al.
    Int J Mol Sci, 2019 Jan 16;20(2).
    PMID: 30654535 DOI: 10.3390/ijms20020365
    Morus alba is an important medicinal plant that is used to treat human diseases. The leaf, branch, and root of Morus can be applied as antidiabetic, antioxidant, and anti-inflammatory medicines, respectively. To explore the molecular mechanisms underlying the various pharmacological functions within different parts of Morus, organ-specific proteomics were performed. Protein profiles of the Morus leaf, branch, and root were determined using a gel-free/label-free proteomic technique. In the Morus leaf, branch, and root, a total of 492, 414, and 355 proteins were identified, respectively, including 84 common proteins. In leaf, the main function was related to protein degradation, photosynthesis, and redox ascorbate/glutathione metabolism. In branch, the main function was related to protein synthesis/degradation, stress, and redox ascorbate/glutathione metabolism. In root, the main function was related to protein synthesis/degradation, stress, and cell wall. Additionally, organ-specific metabolites and antioxidant activities were analyzed. These results revealed that flavonoids were highly accumulated in Morus root compared with the branch and leaf. Accordingly, two root-specific proteins named chalcone flavanone isomerase and flavonoid 3,5-hydroxylase were accumulated in the flavonoid pathway. Consistent with this finding, the content of the total flavonoids was higher in root compared to those detected in branch and leaf. These results suggest that the flavonoids in Morus root might be responsible for its biological activity and the root is the main part for flavonoid biosynthesis in Morus.
    Matched MeSH terms: Genes, Plant
  14. Dek MSP, Padmanabhan P, Sherif S, Subramanian J, Paliyath AG
    Int J Mol Sci, 2017 Jul 15;18(7).
    PMID: 28714880 DOI: 10.3390/ijms18071533
    Phosphatidylinositol 3-kinase (PI3K) is a key enzyme that phosphorylates phosphatidylinositol at 3'-hydroxyl position of the inositol head group initiating the generation of several phosphorylated phosphatidylinositols, collectively referred to as phosphoinositides. The function of PI3K in plant senescence and ethylene signal transduction process was studied by expression ofSolanum lycopersicumPI3K in transgenicNicotiana tabacum, and delineating its effect on flower senescence. Detached flowers of transgenic tobacco plants with overexpressedSl-PI3K(OX) displayed accelerated senescence and reduced longevity, when compared to the flowers of wild type plants. Flowers from PI3K-overexpressing plants showed enhanced ethylene production and upregulated expression of 1-aminocyclopropane-1-carboxylic acid oxidase 1 (ACO1). Real time polymerase chain reaction (PCR) analysis showed thatPI3Kwas expressed at a higher level in OX flowers than in the control. Seedlings of OX-lines also demonstrated a triple response phenotype with characteristic exaggerated apical hook, shorter hypocotyls and increased sensitivity to 1-aminocyclopropane-1-carboxylate than the control wild type seedlings. In floral tissue from OX-lines,Solanum lycopersicumphosphatidylinositol 3-kinase green fluorescent protein (PI3K-GFP) chimera protein was localized primarily in stomata, potentially in cytoplasm and membrane adjacent to stomatal pores in the guard cells. Immunoblot analysis of PI3K expression in OX lines demonstrated increased protein level compared to the control. Results of the present study suggest that PI3K plays a crucial role in senescence by enhancing ethylene biosynthesis and signaling.
    Matched MeSH terms: Genes, Plant
  15. Law YS, Gudimella R, Song BK, Ratnam W, Harikrishna JA
    Int J Mol Sci, 2012;13(7):9343-9362.
    PMID: 22942769 DOI: 10.3390/ijms13079343
    Many of the plant leucine rich repeat receptor-like kinases (LRR-RLKs) have been found to regulate signaling during plant defense processes. In this study, we selected and sequenced an LRR-RLK gene, designated as Oryza rufipogon receptor-like protein kinase 1 (OrufRPK1), located within yield QTL yld1.1 from the wild rice Oryza rufipogon (accession IRGC105491). A 2055 bp coding region and two exons were identified. Southern blotting determined OrufRPK1 to be a single copy gene. Sequence comparison with cultivated rice orthologs (OsI219RPK1, OsI9311RPK1 and OsJNipponRPK1, respectively derived from O. sativa ssp. indica cv. MR219, O. sativa ssp. indica cv. 9311 and O. sativa ssp. japonica cv. Nipponbare) revealed the presence of 12 single nucleotide polymorphisms (SNPs) with five non-synonymous substitutions, and 23 insertion/deletion sites. The biological role of the OrufRPK1 as a defense related LRR-RLK is proposed on the basis of cDNA sequence characterization, domain subfamily classification, structural prediction of extra cellular domains, cluster analysis and comparative gene expression.
    Matched MeSH terms: Genes, Plant/physiology*
  16. Nejat N, Vadamalai G, Dickinson M
    Int J Mol Sci, 2012;13(2):2301-2313.
    PMID: 22408455 DOI: 10.3390/ijms13022301
    Madagascar periwinkle is an ornamental and a medicinal plant, and is also an indicator plant that is highly susceptible to phytoplasma and spiroplasma infections from different crops. Periwinkle lethal yellows, caused by Spiroplasma citri, is one of the most devastating diseases of periwinkle. The response of plants to S. citri infection is very little known at the transcriptome level. In this study, quantitative real-time PCR (RT-qPCR) was used to investigate the expression levels of four selected genes involved in defense and stress responses in naturally and experimentally Spiroplasma citri infected periwinkles. Strictosidine β-glucosidase involved in terpenoid indole alkaloids (TIAs) biosynthesis pathway showed significant upregulation in experimentally and naturally infected periwinkles. The transcript level of extensin increased in leaves of periwinkles experimentally infected by S. citri in comparison to healthy ones. A similar level of heat shock protein 90 and metallothionein expression was observed in healthy, naturally and experimentally spiroplasma-diseased periwinkles. Overexpression of Strictosidine β-glucosidase demonstrates the potential utility of this gene as a host biomarker to increase the fidelity of S. citri detection and can also be used in breeding programs to develop stable disease-resistance varieties.
    Matched MeSH terms: Genes, Plant
  17. Lau ET, Khew CY, Hwang SS
    J Biotechnol, 2020 May 20;314-315:53-62.
    PMID: 32302654 DOI: 10.1016/j.jbiotec.2020.03.014
    Black pepper is an important commodity crop in Malaysia that generates millions of annual revenue for the country. However, black pepper yield is affected by slow decline disease caused by a soil-borne fungus Fusarium solani. RNA sequencing transcriptomics approach has been employed in this study to explore the differential gene expression in susceptible Piper nigrum L. and resistant Piper colubrinum Link. Gene expression comparative analysis of the two pepper species has yielded 2,361 differentially expressed genes (DEGs). Among them, higher expression of 1,426 DEGs was detected in resistant plant. These DEGs practically demonstrated the major branches of plant-pathogen interaction pathway (Path: ko04626). We selected five groups of defence-related DEGs for downstream qRT-PCR analysis. Cf-9, the gene responsible for recognizing fungal avirulence protein activity was found inexpressible in susceptible plant. However, this gene exhibited promising expression in resistant plant. Inactivation of Cf-9 could be the factor that causes susceptible plant fail in recognition of F. solani and subsequently delay activation of adaptive response to fungal invasion. This vital study advance the understanding of pepper plant defence in response to F. solani and aid in identifying potential solution to manage slow decline disease in black pepper cultivation.
    Matched MeSH terms: Genes, Plant/genetics
  18. Chow KS, Mat-Isa MN, Bahari A, Ghazali AK, Alias H, Mohd-Zainuddin Z, et al.
    J Exp Bot, 2012 Mar;63(5):1863-71.
    PMID: 22162870 DOI: 10.1093/jxb/err363
    The cytosolic mevalonate (MVA) pathway in Hevea brasiliensis latex is the conventionally accepted pathway which provides isopentenyl diphosphate (IPP) for cis-polyisoprene (rubber) biosynthesis. However, the plastidic 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway may be an alternative source of IPP since its more recent discovery in plants. Quantitative RT-PCR (qRT-PCR) expression profiles of genes from both pathways in latex showed that subcellular compartmentalization of IPP for cis-polyisoprene synthesis is related to the degree of plastidic carotenoid synthesis. From this, the occurrence of two schemes of IPP partitioning and utilization within one species is proposed whereby the supply of IPP for cis-polyisoprene from the MEP pathway is related to carotenoid production in latex. Subsequently, a set of latex unique gene transcripts was sequenced and assembled and they were then mapped to IPP-requiring pathways. Up to eight such pathways, including cis-polyisoprene biosynthesis, were identified. Our findings on pre- and post-IPP metabolic routes form an important aspect of a pathway knowledge-driven approach to enhancing cis-polyisoprene biosynthesis in transgenic rubber trees.
    Matched MeSH terms: Genes, Plant/genetics
  19. Ng CH, Lee SL, Ng KK, Muhammad N, Ratnam W
    J Genet, 2009 Apr;88(1):25-31.
    PMID: 19417541
    The mating system and seed variation of Acacia hybrid (A. mangium x A. auriculiformis) were studied using allozymes and random amplified polymorphic DNA (RAPD) markers, respectively. Multi-locus outcrossing rate estimations indicated that the hybrid was predominantly outcrossed (mean+/- s.e. t(m) = 0.86+/-0.01). Seed variation was investigated using 35 polymorphic RAPD fragments. An analysis of molecular variance (AMOVA) revealed the highest genetic variation among seeds within a pod (66%-70%), followed by among pods within inflorescence (29%-37%), and the least variation among inflorescences within tree (1%). In addition, two to four RAPD profiles could be detected among seeds within pod. Therefore, the results suggest that a maximum of four seeds per pod could be sampled for the establishment of a mapping population for further studies.
    Matched MeSH terms: Genes, Plant
  20. Sultana S, Khew CY, Morshed MM, Namasivayam P, Napis S, Ho CL
    J Plant Physiol, 2012 Feb 15;169(3):311-8.
    PMID: 22024734 DOI: 10.1016/j.jplph.2011.09.004
    Monodehydroascorbate reductase (MDHAR), an important enzyme of the ascorbate-glutathione cycle, is involved in salt tolerance of plants through scavenging of reactive oxygen species (ROS). In this study, a cDNA encoding MDHAR from the mangrove plant Acanthus ebracteatus was introduced into rice to examine its role in salt tolerance. Three stable transgenic lines (MT22, MT24 and MT25) overexpressing AeMDHAR were selected in vitro using hygromycin and confirmed by PCR, quantitative reverse-transcription (qRT) PCR and enzyme assay. The transgenic line MT24 was predicted to possess a single copy of the transgene while the other two transgenic lines were predicted to have multiple transgene integrations. The AeMDHAR transcripts were detected only in transgenic rice lines but not in untransformed rice. The abundance of AeMDHAR transcripts in transgenic lines MT22 and MT25 was approximately 2.75 times the amount found in MT24. The transgenic rice lines overexpressing AeMDHAR showed a significant increase in MDHAR enzyme activity compared to untransformed plants under both NaCl and control conditions. All transgenic lines showed better yield attributes such as a higher tiller number and increased 1000-grain weight compared to non-transgenics. They also showed tolerance to salt at germination and seedling stages. The transgenic line MT24, which harbors a single copy of AeMDHAR, displayed a lower rate of sterility, a higher number of tillers and longer panicle compared to untransformed plants when subjected to salt stress.
    Matched MeSH terms: Genes, Plant
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