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排序方式: 共有73条查询结果,搜索用时 15 毫秒
61.
Natural products and plant disease resistance. 总被引:74,自引:0,他引:74
Plants elaborate a vast array of natural products, many of which have evolved to confer selective advantage against microbial attack. Recent advances in molecular technology, aided by the enormous power of large-scale genomics initiatives, are leading to a more complete understanding of the enzymatic machinery that underlies the often complex pathways of plant natural product biosynthesis. Meanwhile, genetic and reverse genetic approaches are providing evidence for the importance of natural products in host defence. Metabolic engineering of natural product pathways is now a feasible strategy for enhancement of plant disease resistance. 相似文献
62.
A putative lipid transfer protein involved in systemic resistance signalling in Arabidopsis 总被引:5,自引:0,他引:5
Localized attack by a necrotizing pathogen induces systemic acquired resistance (SAR) to subsequent attack by a broad range of normally virulent pathogens. Salicylic acid accumulation is required for activation of local defenses, such as pathogenesis-related protein accumulation, at the initial site of attack, and for subsequent expression of SAR upon secondary, distant challenge. Although salicylic acid moves through the plant, it is apparently not an essential mobile signal. We screened Agrobacterium tumefaciens transfer DNA (tDNA) tagged lines of Arabidopsis thaliana for mutants specifically compromized in SAR. Here we show that Defective in induced resistance 1-1 (dir1-1) exhibits wild-type local resistance to avirulent and virulent Pseudomonas syringae, but that pathogenesis-related gene expression is abolished in uninoculated distant leaves and dir1-1 fails to develop SAR to virulent Pseudomonas or Peronospora parasitica. Petiole exudate experiments indicate that dir1-1 is defective in the production or transmission from the inoculated leaf of an essential mobile signal. DIR1 encodes a putative apoplastic lipid transfer protein and we propose that DIR1 interacts with a lipid-derived molecule to promote long distance signalling. 相似文献
63.
A substantial uncertainty in the Earth's global geochemical water cycle is the amount of water that enters the deep mantle through the subduction and recycling of hydrated oceanic lithosphere. Here we address the question of recycling of water into the deep mantle by characterizing the volatile contents of different mantle components as sampled by ocean island basalts and mid-ocean-ridge basalts. Although all mantle plume (ocean island) basalts seem to contain more water than mid-ocean-ridge basalts, we demonstrate that basalts associated with mantle plume components containing subducted lithosphere--'enriched-mantle' or 'EM-type' basalts--contain less water than those associated with a common mantle source. We interpret this depletion as indicating that water is extracted from the lithosphere during the subduction process, with greater than 92 per cent efficiency. 相似文献
64.
Gilman AG Simon MI Bourne HR Harris BA Long R Ross EM Stull JT Taussig R Bourne HR Arkin AP Cobb MH Cyster JG Devreotes PN Ferrell JE Fruman D Gold M Weiss A Stull JT Berridge MJ Cantley LC Catterall WA Coughlin SR Olson EN Smith TF Brugge JS Botstein D Dixon JE Hunter T Lefkowitz RJ Pawson AJ Sternberg PW Varmus H Subramaniam S Sinkovits RS Li J Mock D Ning Y Saunders B Sternweis PC Hilgemann D Scheuermann RH DeCamp D Hsueh R Lin KM Ni Y Seaman WE Simpson PC O'Connell TD Roach T Simon MI 《Nature》2002,420(6916):703-706
The Alliance for Cellular Signaling is a large-scale collaboration designed to answer global questions about signalling networks. Pathways will be studied intensively in two cells--B lymphocytes (the cells of the immune system) and cardiac myocytes--to facilitate quantitative modelling. One goal is to catalyse complementary research in individual laboratories; to facilitate this, all alliance data are freely available for use by the entire research community. 相似文献
65.
Zusammenfassung Es wird nachgewiesen, dass die menschliche Plazenta enzymatisch Cortisol in ein?
4-3-Ketosteroid mit Glycerol-Seitenkette, welches mehr polar ist als die 20α- und 20β-Derivate des 6-β-OH-Cortisols, umwandeln
kann. Es scheint, dass die Plazenta dieses Steroid das aus dem Urin schwangerer Frauen isoliert wurde, selbst bildet.
相似文献
66.
Precursors to regulatory peptides: their proteolytic processing 总被引:3,自引:0,他引:3
Precursors to regulatory peptides undergo maturation processes which include proteolytic processing. The enzymes involved in this process remove the hydrophobic peptide located at the amino-terminus of the precursor. Endoprotease cleavage also occurs at single and two adjacent basic residues, this is followed by a removal of basic residues located at the C-terminus of the peptides by a carboxypeptidase-like enzyme. 相似文献
67.
M A Duchosal S A Eming P Fischer D Leturcq C F Barbas P J McConahey R H Caothien G B Thornton F J Dixon D R Burton 《Nature》1992,355(6357):258-262
Antibodies are usually prepared from recently boosted animals and reflect ongoing immune responses. In humans, this is restrictive as ethical constraints generally prevent antigen-boosting. Therefore the rich memory compartment of human antibody responses remains largely untapped. Severe combined immune deficiency (SCID) mice populated with human cells allow the stimulation of human antibody memory without the usual constraints. Here we show how peripheral blood lymphocytes can be stimulated by antigen to produce large secondary responses after transfer to SCID mice. Specific monoclonal human Fab fragments can then be isolated from the mice by repertoire cloning even when the human donor's last contact with antigen was more than 17 years ago. 相似文献
68.
69.
Elvin CM Carr AG Huson MG Maxwell JM Pearson RD Vuocolo T Liyou NE Wong DC Merritt DJ Dixon NE 《Nature》2005,437(7061):999-1002
Resilin is a member of a family of elastic proteins that includes elastin, as well as gluten, gliadin, abductin and spider silks. Resilin is found in specialized regions of the cuticle of most insects, providing low stiffness, high strain and efficient energy storage; it is best known for its roles in insect flight and the remarkable jumping ability of fleas and spittle bugs. Previously, the Drosophila melanogaster CG15920 gene was tentatively identified as one encoding a resilin-like protein (pro-resilin). Here we report the cloning and expression of the first exon of the Drosophila CG15920 gene as a soluble protein in Escherichia coli. We show that this recombinant protein can be cast into a rubber-like biomaterial by rapid photochemical crosslinking. This observation validates the role of the putative elastic repeat motif in resilin function. The resilience (recovery after deformation) of crosslinked recombinant resilin was found to exceed that of unfilled synthetic polybutadiene, a high resilience rubber. We believe that our work will greatly facilitate structural investigations into the functional properties of resilin and shed light on more general aspects of the structure of elastomeric proteins. In addition, the ability to rapidly cast samples of this biomaterial may enable its use in situ for both industrial and biomedical applications. 相似文献
70.
P. A. Dixon 《Cellular and molecular life sciences : CMLS》1958,14(1):37-38
Résumé Une chambre humide pour la micromanipulation a été construite en Perspex. Elle est munie d'un plancher inférieur mobile en verre, qui facilite l'inoculation initiale, la macromanipulation intermédiaire et l'isolement final.
Plexiglas. 相似文献
Plexiglas. 相似文献