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Publikationen - Molekulare Signalverarbeitung

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Publikation

Wang, Q., Grubb, C.D. & Abel, S. Direct analysis of single leaf disks for chemopreventive glucosinolates Phytochem Anal 13, 152 - 157, (2002) DOI: 10.1002/pca.636

Natural isothiocyanates, produced during plant tissue damage from methionine-derived glucosinolates, are potent inducers of mammalian phase 2 detoxification enzymes such as quinone reductase (QR). A greatly simplified bioassay for glucosinolates based on induction and colorimetric detection of QR activity in murine hepatoma cells is described. It is demonstrated that excised leaf disks of Arabidopsis thaliana (ecotype Columbia) can directly and reproducibly substitute for cell-free leaf extracts as inducers of murine QR, which reduces sample preparation to a minimum and maximizes throughput. A comparison of 1 and 3 mm diameter leaf disks indicated that QR inducer potency was proportional to disk circumference (extent of tissue damage) rather than to area. When compared to the QR inducer potency of the corresponding amount of extract, 1 mm leaf disks were equally effective, whereas 3 mm disks were 70% as potent. The QR inducer potency of leaf disks correlated positively with the content of methionine-derived glucosinolates, as shown by the analysis of wild-type plants and mutant lines with lower or higher glucosinolate content. Thus, the microtitre plate-based assay of single leaf disks provides a robust and inexpensive visual method for rapidly screening large numbers of plants in mapping populations or mutant collections and may be applicable to other glucosinolate-producing species.

Publikation

Grubb, C.D., Gross, H.B., Chen, D.L. & Abel, S. Identification of Arabidopsis mutants with altered glucosinolate profiles based on isothiocyanate bioactivity Plant Sci 162, 143 - 152, (2002) DOI: 10.1016/S0168-9452(01)00550-7

Glucosinolates are a diverse class of nitrogen- and sulfur-containing secondary metabolites. They are rapidly hydrolyzed on tissue disruption to a number of biologically active compounds that are increasingly attracting interest as anticarcinogenic phytochemicals and crop protectants. Several glucosinolate-derived isothiocyanates are potent chemopreventive agents that favorably modulate carcinogen metabolism in mammals. Methylsulfinylalkyl isothiocyanates, in particular the 4-methylsulfinylbutyl derivative, are selective and potent inducers of mammalian detoxification enzymes such as quinone reductase (QR). Cruciferous plants including Arabidopsis thaliana (L.) Heyhn, synthesize methylsulfinylalkyl glucosinolates, which are derived from methionine. Using a colorimetric assay for QR activity in murine hepatoma cells and high performance liquid chromatography (HPLC) analysis of desulfoglucosinolates, we have demonstrated a strong positive correlation between leaf QR inducer potency and leaf content of methionine-derived glucosinolates in various A. thaliana ecotypes and available glucosinolate mutants. In a molecular genetic approach to glucosinolate biosynthesis, we screened 3000 chemically mutagenized M2 plants of the Columbia ecotype for altered leaf QR inducer potency. Subsequent HPLC analysis of progeny of putative mutants identified six lines with significant and heritable changes in leaf glucosinolate content and composition.

Bücher und Buchkapitel

Scheel, D. & Wasternack, C. Signal transduction in plants: Cross-talk with the environment. In: Plant Signal Transduction (Scheel, D., Wasternack, C.). University Press, Oxford, UK 1-5, (2002)

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Publikation

Feussner, I. & Wasternack, C. The lipoxygenase pathway Annu. Rev. Plant Biol. 53, 275-297, (2002)

Lipid peroxidation is common to all biological systems, both appearing in developmentally and environmentally regulated processes of plants. The hydroperoxy polyunsaturated fatty acids, synthesized by the action of various highly specialized forms of lipoxygenases, are substrates of at least seven different enzyme families. Signaling compounds such as jasmonates, antimicrobial and antifungal compounds such as leaf aldehydes or divinyl ethers, and a plant-specific blend of volatiles including leaf alcohols are among the numerous products. Cloning of many lipoxygenases and other key enzymes within the lipoxygenase pathway, as well as analyses by reverse genetic and metabolic profiling, revealed new reactions and the first hints of enzyme mechanisms, multiple functions, and regulation. These aspects are reviewed with respect to activation of this pathway as an initial step in the interaction of plants with pathogens, insects, or abiotic stress and at distinct stages of development.
Publikation

Ellis, C., Karafyllidis, I., Wasternack, C. & Turner, J.G. The Arabidopsis mutant cev1 links cell wall signaling to jasmonate and ethylene responses The Plant Cell 14, 1557-1566, (2002)

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Publikation

Vigliocco, A., Bonamico, M.B., Alemano, S., Miersch, O. & Abdala, G. Activation of jasmonic acid production in Zea mays L. infected by the maize rough dwarf virus-Río Cuarto. Reversion of symptoms by salicylic acid Biocell 26(3), 369-374, (2002)

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Publikation

Quint, M., Mihaljevic, R., Dussle, C.M., Xu, M.L., Melchinger, A.E. & Lübberstedt, T. Development of RGA-CAPS markers and genetic mapping of candidate genes for SCMV resistance in maize Theor Appl Genet 105, 355-366, (2002)

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Publikation

Schwechheimer, C. & Calderón Villalobos, L.I. Cullin-containing E3 ubiquitin ligases in plant development Curr. Opin. Plant Biol. 7(6), 677-686, (2002)

In eukaryotes, the ubiquitinproteasome system participates in the control of signal transduction events by selectively eliminating regulatory proteins. E3 ubiquitin ligases specifically bind degradation substrates and mediate their poly-ubiquitylation, a prerequisite for their degradation by the 26S proteasome. On the basis of the analysis of the Arabidopsis genome sequence, it is predicted that there are more than 1000 E3 ubiquitin ligases in plants. Several types of E3 ubiquitin ligases have already been characterized in eukaryotes. Recently, some of these E3 enzymes have been implicated in specific plant signaling pathways.

Publikation

Dussle, C.M., Quint, M., Xu, M.L., Melchinger, A.E. & Lübberstedt, T. Conversion of AFLP fragments tightly linked to Scmv1 and Scmv2 into simple PCR-based markers Theor Appl Genet 105, 1190-1195, (2002)

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Publikation

Weichert, H., Kolbe, A., Kraus, A., Wasternack, C. & Feussner, I. Metabolic profiling of oxylipins in germinating cucumber seedlings - lipoxygenase-dependent degradation of triacylglycerols and biosynthesis of volatile aldehydes Planta 215, 612-619, (2002)

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