title: Cryptogein-induced transcriptional reprogramming in tobacco is light dependent.
abstract: The fungal elicitor cryptogein triggers a light-dependent hypersensitive response in tobacco (Nicotiana tabacum). To assess the effect of light on this nonhost resistance in more detail, we studied various aspects of the response under dark and light conditions using the tobacco-cryptogein experimental system. Here, we show that light drastically alters the plant's transcriptional response to cryptogein, notably by dampening the induction of genes involved in multiple processes, such as ethylene biosynthesis, secondary metabolism, and glutathione turnover. Furthermore, chlorophyll fluorescence measurements demonstrated that quantum yield and functioning of the light-harvesting antennae decreased simultaneously, indicating that photoinhibition underlies the observed decreased photosynthesis and that photooxidative damage might be involved in the establishment of the altered response. Analysis of the isomer distribution of hydroxy fatty acids illustrated that, in the light, lipid peroxidation was predominantly due to the production of singlet oxygen. Differences in (reduced) glutathione concentrations and the rapid development of symptoms in the light when cryptogein was coinfiltrated with glutathione biosynthesis inhibitors suggest that glutathione might become a limiting factor during the cryptogein-induced hypersensitive response in the dark and that this response might be modified by an increased antioxidant availability in the light.
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Hoeberichts
authors.forename: Céline
authors.initials: C
authors.lastname: Davoine
authors.forename: Michaël
authors.initials: M
authors.lastname: Vandorpe
authors.forename: Stijn
authors.initials: S
authors.lastname: Morsa
authors.forename: Brigitte
authors.initials: B
authors.lastname: Ksas
authors.forename: Catherine
authors.initials: C
authors.lastname: Stassen
authors.forename: Christian
authors.initials: C
authors.lastname: Triantaphylidès
authors.forename: Frank
authors.initials: F
authors.lastname: Van Breusegem
mesh_terms: D053898:Biosynthetic Pathways; D060467:Disease Resistance; D005656:Fungal Proteins / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects* / Q000528:radiation effects; D005982:Glutathione Transferase / Q000378:metabolism / Q000502:physiology; D016695:Glycosyltransferases / Q000378:metabolism / Q000502:physiology; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics; D014026:Nicotiana / Q000187:drug effects* / Q000382:microbiology / Q000528:radiation effects
chemical_list: D005656:Fungal Proteins; D054883:Oxylipins; D016695:Glycosyltransferases; D005982:Glutathione Transferase