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Selective desensitization of jasmonate- and pH-dependent signaling in the induction of benzophenanthridine biosynthesis in cells of Eschscholzia californica

Item Type:Article
Title:Selective desensitization of jasmonate- and pH-dependent signaling in the induction of benzophenanthridine biosynthesis in cells of Eschscholzia californica
Creators Name:Faerber, K. and Schumann, B. and Miersch, O. and Roos, W.
Abstract:The biosynthesis of benzophenanthridine alkaloids, phytoalexins of Eschscholzia californica, in cultured cells can be induced by a glycoprotein preparation from yeast, methyljasmonate, artificial acidification with permeant acids, or mild osmotic stress. Each of these stimuli strongly attenuated the subsequent response to the same stimulus (homologous desensitization). Elicitor contact and artificial acidification mutually desensitized the cells for either signal. In contrast, elicitor-treated cells maintained their responsiveness to methyljasmonate or hyperosmolarity (sorbitol). Elicitor concentrations that nearly saturated the alkaloid response did not cause a detectable increase of jasmonate content. Transient acidification of the cytoplasm is a necessary step of signaling by low elicitor concentrations but was not detectable after jasmonate treatment. Seen together, the data indicate the existence of a jasmonate-dependent and jasmonate-independent (ApH controlled) signal pathway towards the expression of benzophenanthridine biosynthesis. Selective desensitization allows either stimulus to activate a distinct share of the biosynthetic capacity of the cell and limits the accumulation of toxic defense metabolites.
Keywords:Eschscholzia Californica, Papaveraceae, Cell Biology, Benzophenanthridine Alkaloids, Jasmonates, Signal Transduction, PH Signaling, Desensitization
Source:Phytochemistry
ISSN:0031-9422
Publisher:Pergamon-Elsevier Science Ltd (England)
Volume:62
Number:3
Page Range:491-500
Date:February 2003
Official Publication:https://doi.org/10.1016/S0031-9422(02)00562-9
PubMed:View item in PubMed

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