title: The nexus between growth and defence signalling: auxin and cytokinin modulate plant immune response pathways.
abstract: Plants deploy a finely tuned balance between growth and defence responses for better fitness. Crosstalk between defence signalling hormones such as salicylic acid (SA) and jasmonates (JAs) as well as growth regulators plays a significant role in mediating the trade-off between growth and defence in plants. Here, we specifically discuss how the mutual antagonism between the signalling of auxin and SA impacts on plant growth and defence. Furthermore, the synergism between auxin and JA benefits a class of plant pathogens. JA signalling also poses growth cuts through auxin. We discuss how the effect of cytokinins (CKs) is multifaceted and is effective against a broad range of pathogens in mediating immunity. The synergism between CKs and SA promotes defence against biotrophs. Reciprocally, SA inhibits CK-mediated growth responses. Recent reports show that CKs promote JA responses; however, in a feedback loop, JA suppresses CK responses. We also highlight crosstalk between auxin and CKs and discuss their antagonistic effects on plant immunity. Efforts to minimize the negative effects of auxin on immunity and a reduction in SA- and JA-mediated growth losses should lead to better sustainable plant protection strategies.
authors.affiliation: Functional Genomics and Systems Biology Group, Department of Bioinformatics, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Naseem
authors.affiliation: Functional Genomics and Systems Biology Group, Department of Bioinformatics, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Kaltdorf
authors.affiliation: Functional Genomics and Systems Biology Group, Department of Bioinformatics, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany dandekar@biozentrum.uni-wuerzburg.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dandekar
mesh_terms: D003517:Cyclopentanes / Q000378:metabolism; D003583:Cytokinins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D063245:Plant Development; D010937:Plant Growth Regulators / Q000378:metabolism*; D057865:Plant Immunity; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D003517:Cyclopentanes; D003583:Cytokinins; D007210:Indoleacetic Acids; D054883:Oxylipins; D010937:Plant Growth Regulators; C011006:jasmonic acid; D020156:Salicylic Acid
keywords: ETI; PTI; auxin; cytokinin; immunity; interaction; pathogen; pathway.