title: Jasmonic acid does not mediate root growth responses to wounding in Arabidopsis thaliana.
abstract: Jasmonic acid (JA) is a crucial plant defence signalling substance that has recently been shown to mediate herbivory-induced root growth reduction in the ecological model species Nicotiana attenuata. To clarify whether JA-induced reduction of root growth might be a general response increasing plant fitness under biotic stress, a suite of experiments was performed with the model plant Arabidopsis thaliana. JA bursts were elicited in leaves of A. thaliana in different ways. Root growth reduction was neither induced by foliar application of herbivore oral secretions nor by direct application of methyl jasmonate to leaves. Root growth reduction was observed when leaves were infected with the pathogen Pseudomonas syringae pv. tomato, which persistently induces the JA signalling pathway. Yet, high resolution growth analyses of this effect in wild type and JA biosynthesis knock-out mutants showed that it was elicited by the bacterial toxin coronatine that suggests ethylene- but not JA-induced root growth reduction in A. thaliana. Overall, the results demonstrate that the reaction of root growth to herbivore-induced JA signalling differs among species, which is discussed in the context of different ecological defence strategies among species.
authors.affiliation: Institut Phytosphäre (ICG-3), Forschungszentrum Jülich GmbH, Jülich, Germany.
authors.forename: Lilian
authors.initials: L
authors.lastname: Schmidt
authors.forename: Grégoire M
authors.initials: GM
authors.lastname: Hummel
authors.forename: Matthias
authors.initials: M
authors.lastname: Schöttner
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schurr
authors.forename: Achim
authors.initials: A
authors.lastname: Walter
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism* / Q000494:pharmacology; D003521:Cyclopropanes / Q000494:pharmacology; D005030:Ethylenes / Q000378:metabolism; D055786:Gene Knockout Techniques; D007192:Indenes / Q000494:pharmacology; D054883:Oxylipins / Q000378:metabolism* / Q000494:pharmacology; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development*; D044224:Pseudomonas syringae; D015398:Signal Transduction; D018411:Spodoptera
chemical_list: D000085:Acetates; D000596:Amino Acids; D003517:Cyclopentanes; D003521:Cyclopropanes; D005030:Ethylenes; D007192:Indenes; D054883:Oxylipins; C058487:coronatine; C011006:jasmonic acid; C072239:methyl jasmonate; C036216:ethylene