Metabolism of stilbene phytoalexins in grapevines: Oxidation of resveratrol in single-cell cultures

Authors

  • G. Hoos
  • R. Blaich

DOI:

https://doi.org/10.5073/vitis.1988.27.1-12

Keywords:

cell, tissue culture, phytoalexin, phenol, enzyme, oxidation, resistance, variety of vine

Abstract

Single-cell cultures of the fungus resistant grapevine varieties Pollux and Sirius and the susceptible ones Riesling and Optima have been established to study the metabolism of the stilbene phytoalexins resveratrol and viniferin. Cells of different varieties showed morphological differences (form and mechanical resistance) and their susceptibility to treatment with debris of killed mycelium of Bot1ytis cinerea reflected the varietal resistance under natural conditions. Most cells of Riesling and Optima were killed by toxic components of the mycelium within 60 h, whereas cultures of Pollux and Sirius showed only slight damage.
Two types of peroxidases have been characterized which can take resveratrol as a substrate converting it to a brown pigment. Viniferin was observed as an intermediate product. Peroxidase activity in suscpetible varieties was reduced as compared to the resistant ones. The oxidation products of resveratrol inhibited the activity of peroxidase.
The function of stilbene phytoalexins as precursors of lignin-like substances is discussed.

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Published

2015-12-15

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