Journal article

The glutathione-deficient mutant pad2-1 accumulates lower amounts of glucosinolates and is more susceptible to the insect herbivore Spodoptera littoralis

  • Schlaeppi, Klaus Department of Biology, University of Fribourg, Switzerland
  • Bodenhausen, Natacha Department of Plant Molecular Biology, University of Lausanne, Switzerland - Ecology & Evolution, University of Chicago, USA
  • Buchala, Antony J. Department of Biology, University of Fribourg, Switzerland
  • Mauch, Felix Department of Biology, University of Fribourg, Switzerland
  • Reymond, Philippe Department of Plant Molecular Biology, University of Lausanne, Switzerland
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    08.05.2008
Published in:
  • The Plant Journal. - 2008, vol. 55, no. 5, p. 774 - 786
English Plants often respond to pathogen or insect attack by inducing the synthesis of toxic compounds such as phytoalexins and glucosinolates (GS). The Arabidopsis mutant pad2-1 has reduced levels of the phytoalexin camalexin and is known for its increased susceptibility to fungal and bacterial pathogens. We found that pad2-1 is also more susceptible to the generalist insect Spodoptera littoralis but not to the specialist Pieris brassicae. The PAD2 gene encodes a γ-glutamylcysteine synthetase that is involved in glutathione (GSH) synthesis, and consequently the pad2-1 mutant contains about 20% of the GSH found in wild-type plants. Lower GSH levels of pad2-1 were correlated with reduced accumulation of the two major indole and aliphatic GSs of Arabidopsis, indolyl-3-methyl-GS and 4-methylsulfinylbutyl-GS, in response to insect feeding. This effect was specific to GSH, was not complemented by treatment of pad2-1 with the strong reducing agent dithiothreitol, and was not observed with the ascorbate-deficient mutant vtc1-1. In contrast to the jasmonate-insensitive mutant coi1-1, expression of insect-regulated and GS biosynthesis genes was not affected in pad2-1. Our data suggest a crucial role for GSH in GS biosynthesis and insect resistance.
Faculty
Faculté des sciences et de médecine
Department
Département de Biologie
Language
  • English
Classification
Biology
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/300970
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