82 research outputs found

    Insect pest management with sex pheromone precursors from engineered oilseed plants

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    Pheromones have become an environmentally friendly alternative to conventional insecticides for pest control. Most current pheromone-based pest control products target lepidopteran pests of high-value crops, as today’s manufacturing processes cannot yet produce pheromones at low enough costs to enable their use for lower-value crops, especially commodity crops. Camelina sativa seeds genetically modified to express (Z)-11-hexadecenoic acid, a sex pheromone precursor of several moth species, provided the oil from which the precursor was isolated, purified and transformed into the final pheromone. Trap lures containing this pheromone were then assessed for their capacity to manage moth pests in the field. Plant-derived pheromone lures proved equally effective as synthetic pheromone lures in monitoring the diamondback moth, Plutella xylostella, in cabbage and disrupting mating of cotton bollworm, Helicoverpa armigera, in common bean fields. Our study demonstrates the biological efficacy and economic feasibility of pheromone production in plant factories by metabolic engineering of an oilseed crop

    Identification and functional analysis of the genes encoding Δ6-desaturase from Ribes nigrum†

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    Gamma-linolenic acid (γ-linolenic acid, GLA; C18:3 Δ6, 9, 12) belongs to the omega-6 family and exists primarily in several plant oils, such as evening primrose oil, blackcurrant oil, and borage oil. Δ6-desaturase is a key enzyme involved in the synthesis of GLA. There have been no previous reports on the genes encoding Δ6-desaturase in blackcurrant (Ribes nigrum L.). In this research, five nearly identical copies of Δ6-desaturase gene-like sequences, named RnD8A, RnD8B, RnD6C, RnD6D, and RnD6E, were isolated from blackcurrant. Heterologous expression in Saccharomyces cerevisiae and/or Arabidopsis thaliana confirmed that RnD6C/D/E were Δ6-desaturases that could use both α-linolenic acids (ALA; C18:3 Δ9,12,15) and linoleic acid (LA; C18:2 Δ9,12) precursors in vivo, whereas RnD8A/B were Δ8-sphlingolipid desaturases. Expression of GFP tagged with RnD6C/D/E showed that blackcurrant Δ6-desaturases were located in the mitochondrion (MIT) in yeast and the endoplasmic reticulum (ER) in tobacco. GC-MS results showed that blackcurrant accumulated GLA and octadecatetraenoic acids (OTA; C18:4 Δ6,9,12,15) mainly in seeds and a little in other organs and tissues. RT-PCR results showed that RnD6C and RnD6E were expressed in all the tissues at a low level, whereas RnD6D was expressed at a high level only in seeds, leading to the accumulation of GLA and OTA in seeds. This research provides new insights to our understanding of GLA synthesis and accumulation in plants and the evolutionary relationship of this class of desaturases, and new clues as to the amino acid determinants which define precise enzyme activity

    Production of very long chain polyunsaturated omega-3 and omega-6 fatty acids in plants

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    We report the production of two very long chain polyunsaturated fatty acids, arachidonic acid (AA) and eicosapentaenoic acid (EPA), in substantial quantities in a higher plant. This was achieved using genes encoding enzymes participating in the ω3/6 Δ8-desaturation biosynthetic pathways for the formation of C20 polyunsaturated fatty acids. Arabidopsis thaliana was transformed sequentially with genes encoding a Δ9-specific elongating activity from Isochrysis galbana, a Δ8-desaturase from Euglena gracilis and a Δ5-desaturase from Mortierella alpina. Instrumental in the successful reconstitution of these C20 polyunsaturated fatty acid biosynthetic pathways was the I. galbana C18-Δ9-elongating activity, which may bypass rate-limiting steps present in the conventional Δ6-desaturase/elongase pathways. The accumulation of EPA and AA in transgenic plants is a breakthrough in the search for alternative sustainable sources of fish oils.&nbsp

    Handbook of Collaborative Management Research

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    As editors of the Handbook of Collaborative Management Research, we began this project with a firm belief based on our experience that broader and deeper collaboration between managers of organizations and academic researchers could yield significant benefits for both parties. Managers would learn much more about how organizations function and new approaches to managing complex systems, thereby improving their individual and orga- nizational performance. Researchers would have access to organizations to discover and test new theories and hypotheses, thereby advancing knowledge and using it to enhance undergraduate, graduate, and executive education. What we didn’t realize at the time was how much we would learn about colla- borative management research from each other and from our colleagues who have con- tributed papers to this volume. As we began work on the editorial statement and guide- lines for the book, we quickly realized that we held different ideas of what collaborative management research entailed

    The Promise of Collaborative Management Research

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    As editors of the Handbook of Collaborative Management Research, we began this project with a firm belief based on our experience that broader and deeper collaboration between managers of organizations and academic researchers could yield significant benefits for both parties. Managers would learn much more about how organizations function and new approaches to managing complex systems, thereby improving their individual and orga- nizational performance. Researchers would have access to organizations to discover and test new theories and hypotheses, thereby advancing knowledge and using it to enhance undergraduate, graduate, and executive education
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