Signals between Verticillium and Arabidopsis
Final Report Abstract
The aim of the project was to identify metabolites that are exchanged between A. thaliana and V. longisporum and to elucidate their function. The project was divided into two parts: the identification of plant metabolites and of fungal metabolites. A non-targeted metabolite fingerprinting approach by UPLC-MS(TOF) was used to identify metabolic changes in leaves of Arabidopsis upon infection. The most prominent markers that were identified derived from the phenylpropanoid pathway. Quantification of the phenylpropanoids by directed measurements could confirm the accumulation of sinapoyl glucose, coniferin and diverse lignans already at early stages of infection. Analyses of different mutants from the phenylpropanoid pathway suggests that S-lignin can contribute to resistance of Arabidopsis to V. longisporum infection. Additionally, the role of suberin and sphingolipids with α-hydroxy fatty acids in the infection was tested. Suberin analysis did not reveal any involvement of this polymer in the infection. To investigate the functional significance of the α-hydroxylation in fatty acids of sphingolipids, T-DNA insertion mutants of Fatty Acid Hydroxylase genes (FAH1 and FAH2) were analyzed in Arabidopsis. Ceramide and glycosyl ceramide profiles of the double mutant showed a strong reduction of sphingolipids with α-hydroxylated fatty acid moieties and an accumulation of the one without hydroxy group. Additionally enrichment of salicylic acid and its glucoside in the double mutant was shown, which lead to higher resistance to powdery mildew infection, whereas infection with Verticillium resulted in stronger stunting and slightly higher fungal DNA amount in the double mutant plants. The growth of V. longisporum in xylem sap lead to the identification of seven metabolites from tryptophan metabolism, but none of them could be detected in infected plants (neither rape nor Arabidopsis). The establishment of a luciferase based screening assay for testing the ability to induce Verticillium-induced gesnes worked well for the infection on soil but could not be modified successfully for the application of pure substances in sterile culture. In contrast the identification of infection-related substances in planta was very successful. More than 20 substances could be identified that accumulated in the apoplast of rape and Arabidopsis (including SA derivatives and oxylipins). Furthermore 45 markers exclusively accumulated in different tissues of infected rape plants. From the structural information gained by MS² and pseudo MS3 experiments a model for the biosynthesis and degradation of the phytoalexin cyclobrassinin could be assigned in analogy to camalexin biosynthesis in Arabidopsis. In addition five marker groups that derive from fatty acids were detected exclusively in the AWF and were described for the first time in plant-pathogen interactions.
Publications
- (2011) Phenylpropanoids and long chain fatty acid derivatives in the interaction of Arabidopsis thaiana and Verticillium longisporum. PhD thesis
Stefanie König
- (2012) MarVis-Filter: Ranking, Filtering, Adduct and Isotope Correction of Mass Spectrometry Data. Journal of Biomedicine and Biotechnology, Article ID 263910
Kaever, A, Landesfeind M, Possienke M, Feussner K, Ivo Feussner I, Meinicke P
(See online at https://doi.org/10.1155/2012/263910) - (2012) Signals and metabolic consequences during the interaction of Brassicaceae and Verticillium longisporum. PhD thesis
Mareike Possienke
- (2012) The vascular pathogen Verticillium longisporum requires a jasmonic acid-independent 74 COI1 function in roots to elicit disease symptoms in Arabidopsis thaliana shoots. Plant Phys.
Ralhan A, Schöttle S, Thurow, C, Iven T, Feußner I, Polle A, Gatz C
(See online at https://doi.org/10.1104/pp.112.198598) - (2012) Transcriptional activation and production of tryptophan-derived secondary metabolites in Arabidopsis roots contributes to the defense against the fungal vascular pathogen Verticillium longisporum. Mol Plant
Iven T, Konig S, Singh S, Braus-Stromeyer SA, Bischoff M, Tietze LF, Braus GH, Lipka V, Feussner F, Droge-Laser W
(See online at https://doi.org/10.1093/mp/sss044) - (2012) Verticillium longisporum infection affects the leaf apoplastic proteome, metabolome and cell wall properties in Arabidopsis thaliana. Plos One 2e31435
Floerl, S, Majcherczyk A, Possienke M, Feussner K, Tappe H, Gatz C, Feussner I, Kües U, Polle A
(See online at https://doi.org/10.1371/journal.pone.0031435)
