zur Suche springenzur Navigation springenzum Inhalt springen

Publikationen - Molekulare Signalverarbeitung

Sortieren nach: Erscheinungsjahr Typ der Publikation

Zeige Ergebnisse 1 bis 10 von 16.

Publikation

Lee, C-W., Efetova, M., Engelmann, J.C., Kramell, R., Wasternack, C., Ludwig- Müller, J., Hedrich, R. & Deeken, R. Agrobacterium tumefaciens promotes tumor induction by modulating pathogen defense in Arabidopsis thaliana. The Plant Cell 21, 2948 - 2962, (2009) DOI: 10.1105/tpc.108.064576

Agrobacterium tumefaciens causes crown gall disease by transferring and integrating bacterial DNA (T-DNA) into the plant genome. To examine the physiological changes and adaptations during Agrobacterium-induced tumor development, we compared the profiles of salicylic acid (SA), ethylene (ET), jasmonic acid (JA), and auxin (indole-3-acetic acid [IAA]) with changes in the Arabidopsis thaliana transcriptome. Our data indicate that host responses were much stronger toward the oncogenic strain C58 than to the disarmed strain GV3101 and that auxin acts as a key modulator of the Arabidopsis–Agrobacterium interaction. At initiation of infection, elevated levels of IAA and ET were associated with the induction of host genes involved in IAA, but not ET signaling. After T-DNA integration, SA as well as IAA and ET accumulated, but JA did not.

This did not correlate with SA-controlled pathogenesis-related gene expression in the host, although high SA levels in mutant plants prevented tumor development, while low levels promoted it. Our data are consistent with a scenario in which ET and later on SA control virulence of agrobacteria, whereas ET and auxin stimulate neovascularization during tumor formation. We suggest that crosstalk among IAA, ET, and SA balances pathogen defense launched by the host and tumorgrowth initiated by agrobacteria.

Bücher und Buchkapitel

Wasternack, C. Jasmonates in Stress, Growth, and Development. In: Plant Stress Biology (H. Hirt). WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 91 - 118, (2009) ISBN: 978-3-527-32290-9

0
Bücher und Buchkapitel

Dorka, R., Miersch, O., Hause, B., Weik, P. & Wasternack, C. Chronobiologische Phänomene und Jasmonatgehalt bei Viscum album L.. In: Die Mistel in der Tumortherapie 2 (Scheer, R.; Bauer, R.; Bekker, A.; Berg, P. A.; Fintelmann, V.). KVC-Verlag Essen 49-56, (2009) ISBN: 978-3-933351-82

0
Publikation

Flores, R., Gas, M.E., Molina-Serrano, D., Nohales, M.A., Carbonell, A., Gago, S., de la Peña, M. & Daròs, J.A. Viroid replication: rolling-circles, enzymes and ribozymes Viruses 1, 317-334, (2009) DOI: 10.3390/v1020317

0
Publikation

Quint, M., Barkawi, L.S., Fan, K.T., Cohen, J.D. & Gray, W.M. Arabidopsis IAR4 modulates auxin response by regulating auxin homeostasis Plant Physiol 150, 748-758, (2009)

In a screen for enhancers of tir1-1 auxin resistance, we identified two novel alleles of the putative mitochondrial pyruvate dehydrogenase E1α-subunit, IAA-Alanine Resistant4 (IAR4). In addition to enhancing the auxin response defects of tir1-1, iar4 single mutants exhibit numerous auxin-related phenotypes including auxin-resistant root growth and reduced lateral root development, as well as defects in primary root growth, root hair initiation, and root hair elongation. Remarkably, all of these iar4 mutant phenotypes were rescued when endogenous indole-3-acetic acid (IAA) levels were increased by growth at high temperature or overexpression of the YUCCA1 IAA biosynthetic enzyme, suggesting that iar4 mutations may alter IAA homeostasis rather than auxin response. Consistent with this possibility, iar4 mutants exhibit increased Aux/IAA stability compared to wild type under basal conditions, but not in response to an auxin treatment. Measurements of free IAA levels detected no significant difference between iar4-3 and wild-type controls. However, we consistently observed significantly higher levels of IAA-amino acid conjugates in the iar4-3 mutant. Furthermore, using stable isotope-labeled IAA precursors, we observed a significant increase in the relative utilization of the Trp-independent IAA biosynthetic pathway in iar4-3. We therefore suggest that the auxin phenotypes of iar4 mutants are the result of altered IAA homeostasis.

Publikation

Serra, P., Hashemian, S.M.B., Pensabene-Bellavia, G., Gago, S. & Durán-Vila, N. An artifical chimeric derivative of Citrus viroid V involves the terminal left domain in pathogenicity Molecular Plant Pathology 10, 515-522, (2009)

0
Publikation

Weigelt, K., Küster, H., Rutten, T., Fait, A., Fernie, A.R., Miersch, O., Wasternack, C., Emery, R.J.N., Desel, C., Hosein, F., Müller, M., Saalbach, I. & Weber, H. ADP-glucose pyrophosphorylase-deficient pea embryos reveal specific transcriptional and metabolic changes of carbon-nitrogen metabolism and stress responses Plant Physiol 149, 395-411, (2009)

We present a comprehensive analysis of ADP-glucose pyrophosphorylase (AGP)-repressed pea (Pisum sativum) seeds using transcript and metabolite profiling to monitor the effects that reduced carbon flow into starch has on carbon-nitrogen metabolism and related pathways. Changed patterns of transcripts and metabolites suggest that AGP repression causes sugar accumulation and stimulates carbohydrate oxidation via glycolysis, tricarboxylic acid cycle, and mitochondrial respiration. Enhanced provision of precursors such as acetyl-coenzyme A and organic acids apparently support other pathways and activate amino acid and storage protein biosynthesis as well as pathways fed by cytosolic acetyl-coenzyme A, such as cysteine biosynthesis and fatty acid elongation/metabolism. As a consequence, the resulting higher nitrogen (N) demand depletes transient N storage pools, specifically asparagine and arginine, and leads to N limitation. Moreover, increased sugar accumulation appears to stimulate cytokinin-mediated cell proliferation pathways. In addition, the deregulation of starch biosynthesis resulted in indirect changes, such as increased mitochondrial metabolism and osmotic stress. The combined effect of these changes is an enhanced generation of reactive oxygen species coupled with an up-regulation of energy-dissipating, reactive oxygen species protection, and defense genes. Transcriptional activation of mitogen-activated protein kinase pathways and oxylipin synthesis indicates an additional activation of stress signaling pathways. AGP-repressed embryos contain higher levels of jasmonate derivatives; however, this increase is preferentially in nonactive forms. The results suggest that, although metabolic/osmotic alterations in iAGP pea seeds result in multiple stress responses, pea seeds have effective mechanisms to circumvent stress signaling under conditions in which excessive stress responses and/or cellular damage could prematurely initiate senescence or apoptosis.

Publikation

Hause, B., Wasternack, C. & Strack, D. Jasmonates in stress responses and development Phytochemistry 70, 1483 - 1484, (2009)

0
Publikation

Clarke, S.M., Cristescu, S.M., Miersch, O., Harren, F.J.M., Wasternack, C. & Mur, L.A.J. Jasmonates act with salicylic acid to confer basal thermotolerance in Arabidopsis thaliana New Phytol 182, 175-187, (2009)

The cpr5-1 Arabidopsis thaliana mutant exhibits constitutive activation of salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) signalling pathways and displays enhanced tolerance of heat stress (HS). cpr5-1 crossed with jar1-1 (a JA-amino acid synthetase) was compromised in basal thermotolerance, as were the mutants opr3 (mutated in OPDA reductase3) and coi1-1 (affected in an E3 ubiquitin ligase F-box; a key JA-signalling component). In addition, heating wild-type Arabidopsis led to the accumulation of a range of jasmonates: JA, 12-oxophytodienoic acid (OPDA) and a JA-isoleucine (JA-Ile) conjugate. Exogenous application of methyl jasmonate protected wild-type Arabidopsis from HS. Ethylene was rapidly produced during HS, with levels being modulated by both JA and SA. By contrast, the ethylene mutant ein2-1 conferred greater thermotolerance. These data suggest that JA acts with SA, conferring basal thermotolerance while ET may act to promote cell death.

Publikation

Wasternack, C. & Hause, B. Emerging complexity: jasmonate-induced volatiles affect parasitoid choice J Exp Bot 60, 2451-2453, (2009)

0
IPB Mainnav Search