Wolfgang Wirtz

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Pathogen recognition at the plant cell surface typically results in the initiation of a multicomponent defense response. Transient influx of Ca2+ across the plasma membrane is postulated to be part of the signaling chain leading to pathogen resistance. Patch-clamp analysis of parsley protoplasts revealed a novel Ca2+-permeable, La3+-sensitive plasma(More)
The aim of this work was to investigate whether sucrose synthesis in the cytosol of leaf cells is regulated in response to the supply of energy and organic carbon from the chloroplast. Fluxes into sucrose and metabolite levels in wheat (Triticum aestivum var Timmo) leaf protoplasts were compared in a range of light intensities and CO(2) concentrations,(More)
The light activation of photosynthesis has been investigated in spinach palisade cell protoplasts. (1) After a short induction period, maximal rates of photosynthesis are achieved. (2) [14C]Bicarbonate initially labels anionic compounds in the chloroplast and then in the extrachloroplast compartments. These pools saturate within 2-4 min and radioactivity(More)
Metabolite levels have been compared in the dark and during photosynthesis in leaves and protoplasts from spinach, pea, wheat and barley. In protoplasts the subcellular distribution was also studied. The levels of triose phosphates and sugar bisphosphates were high in the light and low in the dark. The hexose phosphates and 3-phosphoglycerate levels in the(More)
A method for determining the subcellular metabolite levels in spinach protoplasts is described. The protoplasts are disrupted by centrifugation through a nylon net, releasing intact chloroplasts which pass through a layer of silicone oil into perchloric acid while the remaining cytoplasmic components remain over the oil and are simultaneously quenched as(More)
An 85-kDa beta-glucosidase/xylosidase (BGX1) was purified from the axenically grown phytopathogenic oomycete, Phytophthora infestans. The bgx1 gene encodes a predicted 61-kDa protein product which, upon removal of a 21 amino acid leader peptide, accumulates in the apoplastic space. Extensive N-mannosylation accounts for part of the observed molecular mass(More)
The phosphatidylcholine exchange protein from bovine liver stimulates the specific transfer of phosphatidylcholine (PC) from rat liver microsomes to mitochondria or phospholipid vesicles (Wirtz, K.W.A., Kamp, H.H., and van Deenen, L.L.M. (1972), Biochim. Biophys. Acta 274, 606). In the present study, it has been established which components of the PC(More)
Disease resistance in plant/pathogen interactions requires sensitive and specific recognition mechanisms for pathogen-derived signals in plants. Cultured parsley (Petroselinum crispum) cells respond to treatment with a crude cell wall preparation derived from the phytopathogenic fungus Phytophthora sojae with transcriptional activation of the same set of(More)
Arylesterase (EC 3.1.1.2) activity in serum was specifically measured using thiophenyl acetate in a mechanized assay at 37 degrees C with 4-bromophenylboronic acid as inhibitor of cholinesterase and hexacyanoferrate-III as indicator. The systematic development of a routine method, apparent limitations of thiophenyl compounds as arylesterase substrates, some(More)