The biosynthesis of phytoalexins in Dianthus caryophyllus L. cell cultures: induction of benzoyl-CoA:anthranilate N-benzoyltransferase activity

Arch Biochem Biophys. 1989 Nov 15;275(1):295-301. doi: 10.1016/0003-9861(89)90376-7.

Abstract

It has been shown that cell cultures of Dianthus caryophyllus L. c.v. Eleganz accumulate N-benzoyl-4-methoxyanthranilic acid, previously identified as the phytoalexin methoxydianthramide B, in response to treatment either with a crude elicitor isolated from the cell walls of Phytophthora megasperma f.sp. glycinea or with a commercial yeast extract. Cell-free extracts from the induced cells efficiently catalyzed the N-benzoylation of anthranilate in the presence of benzoyl-CoA. The partially purified transferase was shown to be specific for anthranilate with almost no activity toward 4-hydroxyanthranilate, whereas acyl donors other than benzoyl-CoA such as salicyloyl-, cinnamoyl-, or 4-coumaroyl-CoA were also accepted. Elicitor treatment of the cells additionally induced an S-adenosyl-L-methionine:N-benzoyl-4-hydroxyanthranilate 4-O-methyltransferase activity. We propose, therefore, that methoxydianthramide B is derived from N-benzoylanthranilic acid via N-benzoyl-4-hydroxyanthranilic acid. Dark-grown cells contained little N-benzoyltransferase activity (approx 8 mu kat/kg), which increased roughly ninefold within 6 h following the addition of the elicitor. In addition, phenylalanine ammonia-lyase activity of the cells increased about twofold under these conditions to a maximum (approx 40 mu kat/kg) at 5 h. The rapid induction of both enzyme activities suggests that the shikimate pathway is of crucial importance in the disease resistance response of carnation cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / biosynthesis*
  • Cell-Free System
  • Cells, Cultured
  • Enzyme Induction
  • Kinetics
  • Molecular Structure
  • Plant Extracts / isolation & purification
  • Plant Extracts / metabolism*
  • Plants / enzymology*
  • Sesquiterpenes
  • Terpenes

Substances

  • Plant Extracts
  • Sesquiterpenes
  • Terpenes
  • phytoalexins
  • Acyltransferases
  • benzoyl-CoA-anthranilate N-benzoyltransferase