Wilf Keller

Saskatchewan Research Council, Saskatoon, Saskatchewan, Canada

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Publications (25)98.76 Total impact

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    ABSTRACT: Background myo-Inositol (Ins) metabolism during early stages of seed development plays an important role in determining the distributional relationships of some seed storage components such as the antinutritional factors, sucrose galactosides (also known as raffinose oligosaccharides) and phytic acid (PhA) (myo-inositol 1,2,3,4,5,6-hexakisphosphate). The former is a group of oligosaccharides, which plays a role in desiccation at seed maturation. They are not easily digested by monogastric animals, hence their flatulence-causing properties. Phytic acid is highly negatively charged, which chelates positive ions of essential minerals and decreases their bioavailability. It is also a major cause of phosphate-related water pollution. Our aim was to investigate the influence of competitive diversion of Ins as common substrate on the biosynthesis of phytate and sucrose galactosides. Results We have studied the initial metabolic patterns of Ins in developing seeds of Brassica napus and determined that early stages of seed development are marked by rapid deployment of Ins into a variety of pathways, dominated by interconversion of polar (Ins phosphates) and non-polar (phospholipids) species. In a time course experiment at early stages of seed development, we show Ins to be a highly significant constituent of the endosperm and seed coat, but with no phytate biosynthesis occurring in either tissue. Phytate accumulation appears to be confined mainly within the embryo throughout seed development and maturation. In our approach, the gene for myo-inositol methyltransferase (IMT), isolated from Mesembryanthemum crystallinum (ice plant), was transferred to B. napus under the control of the seed-specific promoters, napin and phaseolin. Introduction of this new metabolic step during seed development prompted Ins conversion to the corresponding monomethyl ether, ononitol, and affected phytate accumulation. We were able to produce homozygous transgenic lines with 19% - 35% average phytate reduction. Additionally, changes in the raffinose content and related sugars occurred along with enhanced sucrose levels. Germination rates, viability and other seed parameters were unaffected by the IMT transgene over-expression. Conclusions Competitive methylation of Ins during seed development reduces seed antinutritional components and enhances its nutritional characteristics while maintaining adequate phosphate reserves. Such approach should potentially raise the canola market value and likely, that of other crops.
    BMC Plant Biology 05/2013; 13(1):84. DOI:10.1186/1471-2229-13-84 · 3.94 Impact Factor
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    ABSTRACT: The Brassica species occupies a large portion of the world's economically important cultivated crops. These include vegetables, oilseeds, condiments, and forages. These crops are grown globally under a wide range of climatic conditions. With current concerns for food and energy security, expanded use of crop products, and environmental stewardship, there is a pressing need to improve yield through greater efficiency of resource utilization. Water availability is the most limiting factor to crop productivity and with the predicted scarcity, due to climate change and increased nonagricultural demand, improving water use efficiency (WUE) in crop production is an imperative. Consequently, increased carbon assimilation per unit of water used by Brassica crops must not only be realized but this carbon must also be efficiently partitioned into the harvested product. Thus, these plants need to be equipped with the genetic capacity to extract more water from the soil under water-limited conditions, fix more carbon, and transpire less water. There is natural genetic variability for WUE and this can be used for screening germplasm to identify better genotypes. Evaporative demand is the driving force for water loss and WUE can be improved by increasing transpiration efficiency (TE), alteration in crop phenology, increased carbon fixation, and increased harvest index (HI) by greater partitioning of assimilates into harvestable product. Modification of root architecture, leaf morphology, and stomata conductance are important targets for developing cultivars with improved WUE. Drought tolerance is closely associated with WUE and factors contributing to maintenance of metabolic function under water-limited conditions contribute to improved WUE. Studies on Arabidopsis have contributed to significant advances in our understanding of WUE and drought tolerance. The use of genetic engineering and genomic tools has allowed for the incorporation of identified genetic factors for improving WUE and drought tolerance traits and will be vital to the development of new Brassica cultivars. The carbon fixation machinery, a vital component in yield, will require adjustments to deal with anticipated water deficits in order to take advantage of increases in atmospheric carbon dioxide as a result of climate change. Manipulation of assimilate partitioning and selection of genotypes with capacity to store water-soluble carbohydrates in stems that can be remobilized to harvestable structures are targets for improving WUE. To maintain high yields of Brassica crops with economic use of water will require substantial increases in our understanding of the biological processes associated with growth under water-limited conditions. The availability of potential gene targets from the present and future discoveries including rapid advances coming from application of genomic technologies may provide a valuable resource base for development of superior WUE Brassica crops in the coming years.
    Improving Crop Resistance to Abiotic Stress, 03/2012: pages 1301-1314; , ISBN: 9783527328406
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    ABSTRACT: Embryogenesis is central to the life cycle of most plant species. Despite its importance, because of the difficulty associated with embryo isolation, global gene expression programs involved in plant embryogenesis, especially the early events following fertilization, are largely unknown. To address this gap, we have developed methods to isolate whole live Arabidopsis (Arabidopsis thaliana) embryos as young as zygote and performed genome-wide profiling of gene expression. These studies revealed insights into patterns of gene expression relating to: maternal and paternal contributions to zygote development, chromosomal level clustering of temporal expression in embryogenesis, and embryo-specific functions. Functional analysis of some of the modulated transcription factor encoding genes from our data sets confirmed that they are critical for embryogenesis. Furthermore, we constructed stage-specific metabolic networks mapped with differentially regulated genes by combining the microarray data with the available Kyoto Encyclopedia of Genes and Genomes metabolic data sets. Comparative analysis of these networks revealed the network-associated structural and topological features, pathway interactions, and gene expression with reference to the metabolic activities during embryogenesis. Together, these studies have generated comprehensive gene expression data sets for embryo development in Arabidopsis and may serve as an important foundational resource for other seed plants. More information: http://www.cancer-systemsbiology.org/.
    Plant physiology 03/2011; 156(1):346-56. DOI:10.1104/pp.110.171702 · 7.39 Impact Factor
  • Canadian Journal of Plant Science 03/2011; 91(2):379-379. · 0.92 Impact Factor
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    ABSTRACT: Phosphatidylinositol-specific phospholipase C (PtdIns-PLC2) plays a central role in the phosphatidylinositol-specific signal transduction pathway. It catalyses the hydrolysis of membrane-bound phosphatidylinositol 4,5-bisphosphate to produce two second messengers, sn-1,2-diacylglycerol and inositol 1,4,5-trisphosphate. The former is a membrane activator of protein kinase C in mammalian systems, and the latter is a Ca(2+) modulator which induces distinctive oscillating bursts of cytosolic Ca(2+), resulting in regulation of gene expression and activation of proteins. Sustained over-expression of BnPtdIns-PLC2 in transgenic Brassica napus lines brought about an early shift from vegetative to reproductive phases, and shorter maturation periods, accompanied by notable alterations in hormonal distribution patterns in various tissues. The photosynthetic rate increased, while stomata were partly closed. Numerous gene expression changes that included induction of stress-related genes such as glutathione S-transferase, hormone-regulated and regulatory genes, in addition to a number of kinases, calcium-regulated factors and transcription factors, were observed. Other changes included increased phytic acid levels and phytohormone organization patterns. These results suggest the importance of PtdIns-PLC2 as an elicitor of a battery of events that systematically control hormone regulation, and plant growth and development in what may be a preprogrammed mode.
    Plant Cell and Environment 09/2009; 32(12):1664-81. DOI:10.1111/j.1365-3040.2009.02027.x · 5.91 Impact Factor
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    Wilf Keller, Faouzi Bekkaoui
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    ABSTRACT: Seed crops play a major role in the global food and feed supply industries. Cereals, oilseeds, and legumes are the predominant seed crops grown in Canada. Brassica napus L. (canola) is the most important oilseed, and currently contributes over $13 billion to the Canadian economy (Canola Council of Canada). The value of oilseed crops, canola in particular, is expected to grow owing to the increasing demand for food, feed, and bioproduct (including biodiesel) applications. In the last 6 years, the Plant Biotechnology Institute (PBI) of the National Research Council Canada, in partnership with several collaborators, has been involved in the study of oilseed crops genomics, in particular Brassica spp., to improve our understanding of this important crop. The research is providing insights into key gene function that can be applied to the improvement of crop performance, productivity, and quality, to meet the increased demand. PBI has focused its activities on two strategic areas. First, the generation of genomics resources that can be used for the study of B. napus and related species. The resources include the development of expressed sequence tags (ESTs), genomic DNA sequences, and the development of DNA arrays. Secondly, a systematic analysis of seed development and composition aimed at improving our understanding of the seed biology. Similar genomics tools developed in Brassica are now being developed in other crops including flax and legumes. Progressing from genomics to functional genomics, these research engagements will be a significant step towards understanding the molecular processes underlying seed composition, quality, yield, and stress resistance of plants thus facilitating the development of elite germplasm.
    Botany 05/2009; 87(6):519-525. DOI:10.1139/B09-029 · 1.04 Impact Factor
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    ABSTRACT: Brassica species represent several important crops including canola (Brassica napus). Understanding of genetic elements that contribute to seed-associated functions will impact future improvements in the canola crop. Brassica species share a very close taxonomic and molecular relationship with Arabidopsis thaliana. However, there are several subtle but distinct seed-associated agronomic characteristics that differ among the oil seed crop species. To address these, we have generated 67,535 ESTs predominately from Brassica seeds, analyzed these sequences, and identified 10,642 unigenes for the preparation of a targeted seed cDNA array. A set of 10,642 PCR primer pairs was designed and corresponding amplicons were produced for spotting, along with relevant controls. Critical quality control tests produced satisfactory results for use of this microarray in biological experiments. The microarray was also tested with specific RNA targets from embryos, germinating seeds, and leaf tissues. The hybridizations, signal intensities, and overall quality of these slides were consistent and reproducible. Additionally, there are 429 ESTs represented on the array that show no homology with any A. thaliana annotated gene or any gene in the Brassica genome databases or other plant databases; however, all of these probes hybridized to B. napus transcripts, indicating that the array also will be useful in defining expression patterns for genes so far unique to Brassica species.
    Genome 04/2008; 51(3):236-42. DOI:10.1139/G07-115 · 1.56 Impact Factor
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    ABSTRACT: Brassica napus cultivar Westar is non-embryogenic under all standard protocols for induction of microspore embryogenesis; however, the rare embryos produced in Westar microspore cultures, induced with added brassinosteroids, were found to develop into heritably stable embryogenic lines after chromosome doubling. One of the Westar-derived doubled haploid (DH) lines, DH-2, produced up to 30% the number of embryos as the highly embryogenic B. napus line, Topas DH4079. Expression analysis of marker genes for embryogenesis in Westar and the derived DH-2 line, using real-time reverse transcription-PCR, revealed that the timely expression of embryogenesis-related genes such as LEAFY COTYLEDON1 (LEC1), LEC2, ABSCISIC ACID INSENSITIVE3, and BABY BOOM1, and an accompanying down-regulation of pollen-related transcripts, were associated with commitment to embryo development in Brassica microspores. Microarray comparisons of 7 d cultures of Westar and Westar DH-2, using a B. napus seed-focused cDNA array (10 642 unigenes), identified highly expressed genes related to protein synthesis, translation, and response to stimulus (Gene Ontology) in the embryogenic DH-2 microspore-derived cell cultures. In contrast, transcripts for pollen-expressed genes were predominant in the recalcitrant Westar microspores. Besides being embryogenic, DH-2 plants showed alterations in morphology and architecture as compared with Westar, for example epinastic leaves, non-abscised petals, pale flower colour, and longer lateral branches. Auxin, cytokinin, and abscisic acid (ABA) profiles in young leaves, mature leaves, and inflorescences of Westar and DH-2 revealed no significant differences that could account for the alterations in embryogenic potential or phenotype. Various mechanisms accounting for the increased capacity for embryogenesis in Westar-derived DH lines are considered.
    Journal of Experimental Botany 02/2008; 59(10):2857-73. DOI:10.1093/jxb/ern149 · 5.79 Impact Factor
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    ABSTRACT: Fatty acyl esters of phytosterols are a major form of sterol conjugates distributed in many parts of plants. In this study we report an Arabidopsis (Arabidopsis thaliana) gene, AtSAT1 (At3g51970), which encodes for a novel sterol O-acyltransferase. When expressed in yeast (Saccharomyces cerevisiae), AtSAT1 mediated production of sterol esters enriched with lanosterol. Enzyme property assessment using cell-free lysate of yeast expressing AtSAT1 suggested the enzyme preferred cycloartenol as acyl acceptor and saturated fatty acyl-Coenyzme A as acyl donor. Taking a transgenic approach, we showed that Arabidopsis seeds overexpressing AtSAT1 accumulated fatty acyl esters of cycloartenol, accompanied by substantial decreases in ester content of campesterol and beta-sitosterol. Furthermore, fatty acid components of sterol esters from the transgenic lines were enriched with saturated and long-chain fatty acids. The enhanced AtSAT1 expression resulted in decreased level of free sterols, but the total sterol content in the transgenic seeds increased by up to 60% compared to that in wild type. We conclude that AtSAT1 mediates phytosterol ester biosynthesis, alternative to the route previously described for phospholipid:sterol acyltransferase, and provides the molecular basis for modification of phytosterol ester level in seeds.
    Plant physiology 12/2007; 145(3):974-84. DOI:10.1104/pp.107.106278 · 7.39 Impact Factor
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    ABSTRACT: The Polima (pol) system of cytoplasmic male sterility (CMS) and its fertility restorer gene Rfp are used in hybrid rapeseed production in Brassica napus. To facilitate map-based cloning of the Rfp gene, we have successfully transferred the pol cytoplasm and Rfp from the amphidiploid B. napus to the diploid species B. rapa and generated a doubled haploid pol cytoplasm B. rapa population that segregates for the Rfp gene. This was achieved through interspecific crosses, in vitro rescue of hybrid embryos, backcrosses, and microspore culture. Male fertility conditioned by Rfp was shown to co-segregate in this population with Rfp-specific mitochondrial transcript modifications and with DNA markers previously shown to be linked to Rfp in B. napus. The selfed-progeny of one doubled haploid plant were confirmed to be characteristic B. rapa diploids by cytogenetic analysis. Clones recovered from a genomic library derived from this plant line using the RFLP probe cRF1 fell into several distinct physical contigs, one of which contained Rfp-linked polymorphic restriction fragments detected by this probe. This indicates that chromosomal DNA segments anchored in the Rfp region can be recovered from this library and that the library may therefore prove to be a useful resource for the eventual isolation of the Rfp gene.
    Plant Molecular Biology 06/2006; 61(1-2):269-81. DOI:10.1007/s11103-006-0008-9 · 4.07 Impact Factor
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    ABSTRACT: The cloning and identification of full-length cDNA fragments coding for the Brassica napus phosphatidylinositol-specific phospholipase C2 (BnPLC2), phosphatidylinositol 3-kinase (BnVPS34) and phosphatidylinositol synthase (BnPtdIns S1) is described. In addition, two complementary fragments (120 nucleotides long) corresponding to Arabidopsis PtdIns 4-kinase (PtdIns 4-K) and PtdIns-4-phosphate 5-kinase (PtdIns4P 5-K) sequences were chemically synthesized. These, as well as the cDNA clones, were used as probes to study the corresponding steady state mRNA levels in different tissues and developmental stages of B. napus, as well as in response to different environmental conditions. Transcripts corresponding to BnPLC2, BnPtdIns S1, BnVPS34 and PtdIns 4-K were found constitutively expressed at different levels in most tissues, with young leaves, siliques, and developing seeds showing the lowest levels. No detectable PtdIns4P 5-K transcripts were found in buds or flowers. Up-regulation of BnPLC2 was seen in response to low temperature stress, which was notably accompanied by a parallel down-regulation of BnPtdIns S1, while BnVPS34 and PtdIns 4-K remained at control levels. A moderate increase in PtdIns4P 5-K levels was noted. In high salinity conditions BnPtdIns S1, BnVPS34 and BnPLC2 transcripts had similar responses but at different levels, with no major changes detected for PtdIns 4-K or PtdIns4P 5-K. Significantly, all five transcripts increased under drought stress conditions and all stressed plants clearly showed relatively higher levels of total inositol trisphosphate.
    Planta 04/2005; 220(5):777-84. DOI:10.1007/s00425-004-1389-0 · 3.38 Impact Factor
  • In Vitro Cellular & Developmental Biology - Plant 01/2005; 41(4):378-387. · 1.16 Impact Factor
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    ABSTRACT: Approximately 5000 plaques derived from a Brassica napus L. (canola) seed-cDNA library representing 15 days after pollination (DAP) were differentially screened for highly expressed genes at the early stages of seed development. Analysis of 104 differentially expressed sequence tags revealed 54 unique genes, of which 33 had putative homologues described in Arabidopsis thaliana (L.) Heynh. or B. napus. These encoded diverse proteins, ranging from proteins of unknown function to metabolic enzymes and proteins associated with cell structure and development. Twenty-five genes were only expressed in seeds, and 11 of these started to express as early as 5 or 10 DAP. The majority of the seed-specific genes that are expressed at early stages of seed development encoded proteins with high similarity to hypothetical Arabidopsis proteins. Tissue-specificity determined by Northern analysis revealed that four seed-specific genes were expressed only in seed coats and another five in both embryos and seed coats. Analysis of transcript profiles of seed-abundant as well as seed-specific genes, and their expression patterns, implies that the B. napus seed is undergoing an active cell proliferation during 10-20 DAP, while establishing metabolic networks for subsequent seed maturation.
    Planta 02/2004; 218(3):483-91. DOI:10.1007/s00425-003-1124-2 · 3.38 Impact Factor
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    ABSTRACT: We have previously isolated a CCAAT-binding factor B subunit gene ( BnCBF-B) from Brassica napus that is widely expressed in different plant tissues and whose role is still unknown. To investigate the importance of this transcription factor subunit in plant reproductive tissues, we targeted antisense BnCBF-B transcripts to the tapetum of transgenic B. napus plants. Of the 24 independent transformants, 13 yielded reduced quantities of viable pollen, of which five were unable to produce the elongated siliques indicative of normal seed set. The decrease in pollen viability probably resulted from the precocious degeneration of the tapetal cell layer observed in these plants. Surprisingly, the male-sterile phenotype was also accompanied by a decrease in female fertility, which could be due to the expression of the antisense BnCBF-B transcripts in the female reproductive structures of the transgenic plants. These results suggest that the BnCBF-B gene plays a critical non-redundant role in plant reproductive tissues.
    Plant Cell Reports 05/2003; 21(8):804-8. DOI:10.1007/s00299-003-0588-7 · 2.94 Impact Factor
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    ABSTRACT: Flowering plants display a remarkable range of inflorescence architecture, and pedicel characteristics are one of the key contributors to this diversity. However, very little is known about the genes or the pathways that regulate pedicel development. The brevipedicellus (bp) mutant of Arabidopsis thaliana displays a unique phenotype with defects in pedicel development causing downward-pointing flowers and a compact inflorescence architecture. Cloning and molecular analysis of two independent mutant alleles revealed that BP encodes the homeodomain protein KNAT1, a member of the KNOX family. bp-1 is a null allele with deletion of the entire locus, whereas bp-2 has a point mutation that is predicted to result in a truncated protein. In both bp alleles, the pedicels and internodes were compact because of fewer cell divisions; in addition, defects in epidermal and cortical cell differentiation and elongation were found in the affected regions. The downward-pointing pedicels were produced by an asymmetric effect of the bp mutation on the abaxial vs. adaxial sides. Cell differentiation, elongation, and growth were affected more severely on the abaxial than adaxial side, causing the change in the pedicel growth angle. In addition, bp plants displayed defects in cell differentiation and radial growth of the style. Our results show that BP plays a key regulatory role in defining important aspects of the growth and cell differentiation of the inflorescence stem, pedicel, and style in Arabidopsis.
    Proceedings of the National Academy of Sciences 05/2002; 99(7):4730-5. DOI:10.1073/pnas.072626099 · 9.81 Impact Factor
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    ABSTRACT: CYP84 is a recently identified family of cytochrome P450-dependent mono-oxygenases defined by a putative ferulate-5-hydroxylase (F5H) from Arabidopsis. Until recently F5H has been thought to catalyze the hydroxylation of ferulate to 5-OH ferulate en route to sinapic acid. Sinapine, a sinapate-derived ester in the seeds, is antinutritional and a target for elimination in canola meal. We have isolated three F5H-like genes (BNF5H1-3) from a cultivated Brassica napus, whose amphidiploid progenitor is considered to have arisen from a fusion of the diploids Brassica rapa and Brassica oleracea. Two cultivated varieties of the diploids were also found to contain BNF5H3 and additionally either BNF5H1 or BNF5H2, respectively. Whereas all three are >90% identical in their coding sequence, BNF5H1 and BNF5H2 are closer to each other than to BNF5H3. This and additional data suggest that the two groups of genes have diverged in an ancestor of the diploids. B. napus showed maximal F5H expression in the stems, least in the seeds, and subtle differences among the expression profiles of the three genes elsewhere. Transgenic B. napus with cauliflower mosaic virus 35S-antisense BNF5H contained up to 40% less sinapine, from 9.0 +/- 0.3 mg in the controls to 5.3 +/- 0.3 mg g(-1) seed. F5H from Arabidopsis and a similar enzyme from sweetgum (Liquidamber styraciflua) has recently been shown to have coniferaldehyde hydroxylase activity instead of F5H activity. Thus the supply of 5-OH coniferaldehyde or 5-OH ferulate has a bearing on sinapine accumulation in canola seeds.
    Plant physiology 08/2000; 123(4):1623-34. · 7.39 Impact Factor
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    ABSTRACT: CYP84 is a recently identified family of cytochrome P450-dependent mono-oxygenases defined by a putative ferulate-5- hydroxylase (F5H) from Arabidopsis. Until recently F5H has been thought to catalyze the hydroxylation of ferulate to 5-OH ferulate en route to sinapic acid. Sinapine, a sinapate-derived ester in the seeds, is antinutritional and a target for elimination in canola meal. We have isolated three F5H-like genes (BNF5H1-3) from a cultivated Brassica napus, whose amphidiploid progenitor is considered to have arisen from a fusion of the diploids Brassica rapa and Brassica oleracea. Two cultivated varieties of the diploids were also found to contain BNF5H3 and additionally either BNF5H1 or BNF5H2, respectively. Whereas all three are .90% identical in their coding sequence, BNF5H1 and BNF5H2 are closer to each other than to BNF5H3. This and additional data suggest that the two groups of genes have diverged in an ancestor of the diploids. B. napus showed maximal F5H expression in the stems, least in the seeds, and subtle differences among the expression profiles of the three genes elsewhere. Transgenic B. napus with cauliflower mosaic virus 35S-antisense BNF5H contained up to 40% less sinapine, from 9.0 6 0.3 mg in the controls to 5.3 6 0.3 mg g21 seed. F5H from Arabidopsis and a similar enzyme from sweetgum (Liquidamber styraciflua) has recently been shown to have coniferaldehyde hydroxylase activity instead of F5H activity. Thus the supply of 5-OH coniferaldehyde or 5-OH ferulate has a bearing on sinapine accumulation in canola seeds. Secondary metabolism is indeed essential to the form and function of plants and also to the survival of these sessile members in their diverse and dy- namic ecosystems. The products range from rela- tively simple phenolic esters to the complex, hetero- geneous polymers of lignin. These metabolites have a wide range of often disparate functions ranging from providing mechanical strength to pest deterrence to
    Plant physiology 08/2000; 123(4):1623-1634. DOI:10.1104/pp.123.4.1623 · 7.39 Impact Factor
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    ABSTRACT: Glycinebetaine (betaine) affords osmoprotection in bacteria, plants and animals, and protects cell components against harsh conditions in vitro. This and a compelling body of other evidence have encouraged the engineering of betaine production in plants lacking it. We have installed the metabolic step for oxidation of choline, a ubiquitous substance, to betaine in three diverse species, Arabidopsis, Brassica napus, and tobacco (Nicotiana tabacum), by constitutive expression of a bacterial choline oxidase gene. The highest levels of betaine in independent transgenics were 18.6, 12.8, and 13 micromol g(-1) dry weight, respectively, values 10- to 20-fold lower than the levels found in natural betaine producers. However, choline-fed transgenic plants synthesized substantially more betaine. Increasing the choline supplementation further enhanced betaine synthesis, up to 613 micromol g(-1) dry weight in Arabidopsis, 250 micromol g(-1) dry weight in B. napus, and 80 micromol g(-1) dry weight in tobacco. These studies demonstrate the need to enhance the endogenous choline supply to support accumulation of physiologically relevant amounts of betaine. A moderate stress tolerance was noted in some but not all betaine-producing transgenic lines based on relative shoot growth. Furthermore, the responses to stresses such as salinity, drought, and freezing were variable among the three species.
    Plant physiology 04/2000; 122(3):747-56. · 7.39 Impact Factor
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    ABSTRACT: A genomic clone, Pis G363, containing the Brassica napus stigma-expressed gene Pis 63-2 was isolated and sequenced. The coding region of Pis G363 does not possess introns and shows 82% identity to the nucleotide sequence of a gene from Arabidopsis BAC clone T01B08. A 2-kb promoter fragment from Pis G363 was fused to the coding sequence of the marker enzyme β-glucuronidase (GUS) and introduced into tobacco via Agrobacterium-mediated transformation. The promoter fragment directed expression of the GUS gene in the stigma of transgenic tobacco. Some transformants also showed relatively low GUS activity in the pollen.
    Plant Cell Reports 12/1998; 18(5):357-362. DOI:10.1007/s002990050586 · 2.94 Impact Factor