Inactivation and mutagenesis by phototoxins using Escherichia coli strains differing in sensitivity to near- and far-ultraviolet light

R. W. Tuveson, May R. Berenbaum, Ellen E. Heininger

Research output: Contribution to journalArticle

Abstract

Four Escherichia coli strains carrying all the possible combinations of genes controlling sensitivity to near-UV (NUV;nur versus nur+) and far-UV (FUV;uvrA6 versus uvrA+) were inactivated with broad-spectrum NUV together with specific phototoxins. The inactivation kinetics of the four strains are consistent with the previous reports that psoralen and angelicin inactivation is based on the formation of DNA adducts, while xanthotoxin (8-MOP) inactivation is based on the combined effects of DNA adduct formation and oxygen-dependent photodynamic action. At sufficiently high NUV fluences, xanthotoxol (8-HOP) induces lethal DNA lesions in an excision-deficient (uvrA6) strain. Inactivation by alpha-terthienyl plus NUV involves strictly membrane damage since the genes controlling the sensitivity to either NUV or FUV have no effect on inactivation kinetics. Using mutation to histidine independence (his-4+) in the presence of NUV as a measure of mutagenicity by phototoxins, psoralen and xanthotoxin are mutagenic, angelicin is less mutagenic, and xanthotoxol and alpha-terthienyl are not mutagenic. None of the phototoxins tested in the presence of NUV were as mutagenic as FUV. Imperatorin and berberine were neither phototoxic nor mutagenic in this assay system. This assay thus provides a rapid qualitative screening procedure to identify the mode of action and mutagenicity of plant phototoxins with potential insecticidal properties.

Original languageEnglish (US)
Pages (from-to)933-948
Number of pages16
JournalJournal of Chemical Ecology
Volume12
Issue number4
DOIs
StatePublished - Apr 1 1986

Keywords

  • Escherichia coli
  • alpha-terthienyl
  • angelicin
  • histidine independence
  • mutagenesis
  • psoralen
  • xanthotoxin
  • xanthotoxol

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Biochemistry

Fingerprint Dive into the research topics of 'Inactivation and mutagenesis by phototoxins using Escherichia coli strains differing in sensitivity to near- and far-ultraviolet light'. Together they form a unique fingerprint.

  • Cite this