title: A maize line resistant to herbivory constitutively releases (E) -beta-caryophyllene.
abstract: Various pests, such as those in the order Lepidoptera, frequently feed on young maize (Zea mays) plants and pose a significant threat to plant development and survival. To manage this problem, maize generates a wide variety of responses to attack by pests, from activation of wound-response pathways to the release of volatile compounds. Mp708, an inbred line resistant to feeding by the larvae of the fall armyworm (Spodoptera frugiperda J.E. Smith Lepidoptera: Noctuidae), has been developed through traditional breeding methods, but its underlying mechanisms of resistance are still not completely understood. Mp708 has been shown to have a moderately high constitutive expression of jasmonic acid (JA) before infestation by fall armyworm. However, Tx601, a genotype susceptible to feeding by fall armyworm, activates JA pathway only in response to feeding, suggesting that Mp708 is "primed" to respond swiftly to an attack. Current research indicates that fall armyworm show a lack of preference to feeding on Mp708, leading to the hypothesis that volatiles constitutively released by the plant may also play an important role in its resistance. Analysis of volatiles released by Mp708 and Tx601 in the presence and absence of fall armyworm larvae identified (E)-beta-caryophyllene, a terpenoid associated with resistance, released constitutively in Mp708. Fall armyworm fed samples of both Mp708 and Tx601 showed high transcript number of tps23, the gene responsible for the synthesis of (E)-beta-caryophyllene. In addition, fall armyworm larvae show a preference for Tx601 whorl tissue over Mp708 tissue, and the dosage of Tx601 whorl with (E)-beta-caryophyllene repels the fall armyworm.
authors.affiliation: Mississippi State University, Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, 32 Creelman Street, MS 9650, Mississippi State, MS 39762, USA.
authors.forename: W E C
authors.initials: WE
authors.lastname: Smith
authors.forename: R
authors.initials: R
authors.lastname: Shivaji
authors.forename: W P
authors.initials: WP
authors.lastname: Williams
authors.forename: D S
authors.initials: DS
authors.lastname: Luthe
authors.forename: G V
authors.initials: GV
authors.lastname: Sandoya
authors.forename: C L
authors.initials: CL
authors.lastname: Smith
authors.forename: D L
authors.initials: DL
authors.lastname: Sparks
authors.forename: A E
authors.initials: AE
authors.lastname: Brown
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D003517:Cyclopentanes / Q000378:metabolism*; D005518:Food Preferences; D060434:Herbivory; D007814:Larva / Q000254:growth & development / Q000502:physiology; D054883:Oxylipins / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics; D000081223:Polycyclic Sesquiterpenes; D060888:Real-Time Polymerase Chain Reaction; D012717:Sesquiterpenes / Q000378:metabolism*; D018411:Spodoptera / Q000254:growth & development / Q000502:physiology*; D003313:Zea mays / Q000235:genetics / Q000378:metabolism*
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; C011006:jasmonic acid; C024714:caryophyllene; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase