Definition of phytoalexin in English:

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Pronunciation: /ˌfīdōəˈleksən/


A substance that is produced by plant tissues in response to contact with a parasite and that specifically inhibits the growth of that parasite.
Example sentences
  • Plants produce phytoalexins as an immune response to physical, chemical, or biological damage.
  • During infection by fungal pathogens, plant cells respond by expressing a battery of disease response genes, which can result in the production of various toxic plant products, including active oxygen species and phytoalexins.
  • Plant resistance to specific pathogens is often correlated with increased production of phytoalexins, whereas inhibition or deficiency of phytoalexin production allows greater virulence.


1940s: from phyto- 'of plants' + alexin, a name for a class of substances found in blood serum, able to destroy bacteria.

For editors and proofreaders

Syllabification: phy·to·a·lex·in

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