Abstract
Production of C6-aldehydes in plants is induced after infection of pathogen. When Arabidopsis plants were treated with C6-aldehyde, expressions of several defense genes and accumulation of a phytoalexin were induced, and resistance against Botrytis cinerea was also enhanced. By monitoring the defensive response with (E)-2-hexenal-treatment in many Arabidopsis mutants, we found that some mutants were insensitive against the treatment. Mutation of glutathione synthetase I or glutathione reductase 2 (GR2) caused deterioration of response against C6-aldehydes in Arabidopsis. Total glutathione level is reported to contribute to some of defense responses in Arabidopsis. Furthermore, reduction of glutathione activates NPR1-dependent defensive response in Arabidopsis. However, (E)-2-hexenal-treatment resulted in no increase in total glutathione level and in transcriptional level of GR2 in Arabidopsis. (E)-2-Hexenal-induced defensive response might be thus independent of total glutathione amount or NPR1. Probably, the defensive responses depend on other pathway relating to glutathione synthesis.
