Unser 10. Leibniz Plant Biochemistry Symposium am 7. und 8. Mai war ein großer Erfolg. Thematisch ging es in diesem Jahr um neue Methoden und Forschungsansätze der Naturstoffchemie. Die exzellenten Vorträge über Wirkstoffe…
Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Jasmonates are well‐characterized signals in the development of plants and their response to abiotic and biotic stresses, such as touch and wounding by herbivores. A gap in our knowledge on jasmonate‐induced processes, however, is the cellular localization of jasmonates.Here, a novel antibody‐based approach was developed to visualize jasmonates in cross‐sections of plant material. Antibodies raised in rabbits against BSA‐coupled jasmonic acid (JA) are specific for JA, its methyl ester and isoleucine conjugate. They do not bind to 12‐oxophytodienoic acid, 12‐hydoxy‐JA or coronatine. These antibodies were used in combination with newly established fixation and embedding methods.Jasmonates were rapidly and uniformly distributed within all cells near the site of damage of a mechanically wounded tomato (Solanum lycopersicum) leaf. Leaf tissue distally located to the wound site exhibited identical distribution, but had a lower signal intensity. The occurrence of jasmonates in all cell types of a wounded leaf was accompanied by transcript accumulation of early JA‐induced genes visualized by in situ hybridization.With these new antibodies, a powerful tool is available to detect cell‐specifically the occurrence of jasmonates in any jasmonate‐dependent stress response or developmental process of plants.
Jasmonic acid (JA) is a plant signalling compound that has been implicated in the regulation of mutualistic symbioses. In order to understand the spatial distribution of JA biosynthetic capacity in nodules of two actinorhizal species, Casaurina glauca and Datisca glomerata, and one legume, Medicago truncatula, we determined the localization of allene oxide cyclase (AOC) which catalyses a committed step in JA biosynthesis. In all nodule types analysed, AOC was detected exclusively in uninfected cells.The levels of JA were compared in the roots and nodules of the three plant species. The nodules and noninoculated roots of the two actinorhizal species, and the root systems of M. truncatula, noninoculated or nodulated with wild‐type Sinorhizobium meliloti or with mutants unable to fix nitrogen, did not show significant differences in JA levels. However, JA levels in all plant organs examined increased significantly on mechanical disturbance.To study whether JA played a regulatory role in the nodules of M. truncatula, composite plants containing roots expressing an MtAOC1‐sense or MtAOC1‐RNAi construct were inoculated with S. meliloti. Neither an increase nor reduction in AOC levels resulted in altered nodule formation.These data suggest that jasmonates are not involved in the development and function of root nodules.