| Abstract Detail
Plant-Pest Interactions Bodenhausen, Natacha [1], Schlaeppi, Klaus [2], Buchala, Antony [3], Mauch, Felix [3], Reymond, Philippe [4]. The glutathione-deficient mutant pad2-1 is more susceptible to the insect herbivore Spodoptera littoralis. Plants respond to attackers by inducing the synthesis of toxic compounds: insect resistance is often associated with the accumulation of glucosinolates, while resistance against pathogens depends inter alia on the induction of phytoalexins. 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 more susceptible to the insect Spodoptera littoralis. The PAD2 gene encodes a γ-glutamylcysteine synthetase, the enzyme catalyzing the first committed step in glutathione synthesis and consequently the pad2-1 mutant contains only 20% of wild-type glutathione levels. Enhanced herbivore susceptibility was not due to the low camalexin level since the camalexin-deficient mutant pad3-1 showed a normal level of resistance. We measured glucosinolates (GS) in the pad2-1 mutant after insect challenge and found that the accumulation of indolyl-3-methyl-GS and 4-methylsulfinylbutyl-GS were severely reduced compared to wild-type. Interestingly, the expression of GS-biosynthesis genes was not affected in the pad2-1 mutant. Taken together, these results demonstrate that low glutathione levels lead to increased insect susceptibility and correlate with reduced GS accumulation. Log in to add this item to your schedule
1 - University of Lausanne, Department of Plant Molecular Biology, Biophore, Lausanne, 1015, Switzerland 2 - University of Fribour, Department of Biology 3 - University of Fribourg, Department of Biology 4 - University of Lausanne, Department of Plant Molecular Biology
Keywords: glutathione glucosinolate plant-insect interaction gene expression insect pest resistance.
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P14024 Abstract ID:2590 |