title: Systemic defense priming by Pseudomonas putida KT2440 in maize depends on benzoxazinoid exudation from the roots.
abstract: Exudation of benzoxazinoid metabolites from roots of young maize seedlings recruits the rhizobacterial strain Pseudomonas putida KT2440 from the soil to the rhizosphere. In this study, we have investigated whether these rhizobacteria are beneficial for maize by eliciting systemic defense priming. Root colonization of the maize hybrid cultivar Delprim by P. putida primed wound- and jasmonic acid (JA)-inducible emission of aromatic and terpenoid volatiles, but not the emission of the green leaf volatile (Z)-3-hexenyl acetate. Furthermore, root colonization by P. putida primed stress-inducible transcription of the JA-dependent gene SerPIN, whereas JA-dependent induction of the MPI gene was unaffected. Systemic priming of SerPIN by P. putida only occurred in benzoxazinoid-producing plants, and was absent in benzoxazinoid-deficient plants. The results from this study suggest that root colonization by P. putida primes a selection of JA-dependent defenses in Maize, which is reliant on benzoxazinoid exudation from the roots.
authors.affiliation: Centre for Sustainable Soils and Grassland Systems; Rothamsted Research; Harpenden, UK.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Neal
authors.affiliation: Department of Animal and Plant Sciences; University of Sheffield; Sheffield, UK.
authors.forename: Jurriaan
authors.initials: J
authors.lastname: Ton
mesh_terms: D048588:Benzoxazines / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D060467:Disease Resistance; D017343:Genes, Plant; D054883:Oxylipins / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology*; D053147:Plant Exudates; D018517:Plant Roots / Q000378:metabolism* / Q000382:microbiology; D016958:Pseudomonas putida; D014158:Transcription, Genetic; D003313:Zea mays / Q000235:genetics / Q000378:metabolism*
chemical_list: D048588:Benzoxazines; D003517:Cyclopentanes; D054883:Oxylipins; D053147:Plant Exudates; C011006:jasmonic acid