title: Involvement of limonene hydroperoxides formed after oil gland injury in the induction of defense response against Penicillium digitatum in lemon fruit.
abstract: The effects of wounding oil glands of lemon [Citrus limon (L.) Burm.] fruit were investigated. Young mature-green lemons demonstrated significantly lower decay incidence than older yellow fruit when their oil glands were punctured in the presence of postharvest wound pathogen Penicillium digitatum Sacc. Contact with the released gland content on the green lemon surface reduced the viability of P. digitatum spores approximately twice. Wounding caused rapid production of limonene hydroperoxides that persisted for only a few minutes. The magnitude depended on the physiological maturity of the fruit; mature-green fruit produced much higher levels than did yellow lemons. Furthermore, wounding of the oil glands or injection of limonene hydroperoxides into the lemon peel elicited the production of the citrus fruit phytoalexins, scoparone and scopoletin, to levels known to be effective in reducing decay caused by P. digitatum. The mature-green fruit produced about twice as much of these phytoalexins as the older yellow fruit. This induced defensive elicitation of phytoalexin production, as well as the direct effects of these antifungal compounds, markedly inhibited the pathogen in mature-green fruits but was ineffective in older yellow ones.
authors.affiliation: Department of Postharvest Science of Fresh Produce, The Volcani Center, Agricultural Research Organization, Bet Dagan, Israel. sbenyehoshua@gmail.com
authors.forename: Shimshon
authors.initials: S
authors.lastname: Ben-Yehoshua
authors.forename: Victor
authors.initials: V
authors.lastname: Rodov
authors.forename: Beatrice
authors.initials: B
authors.lastname: Nafussi
authors.forename: Xuqiao
authors.initials: X
authors.lastname: Feng
authors.forename: Jin
authors.initials: J
authors.lastname: Yen
authors.forename: Tomer
authors.initials: T
authors.lastname: Koltai
authors.forename: Uri
authors.initials: U
authors.lastname: Nelkenbaum
mesh_terms: D002957:Citrus / Q000502:physiology*; D053138:Cyclohexenes / Q000378:metabolism* / Q000494:pharmacology; D005638:Fruit / Q000382:microbiology / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000378:metabolism* / Q000494:pharmacology; D000077222:Limonene; D009822:Oils, Volatile / Q000378:metabolism; D010407:Penicillium / Q000187:drug effects / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D012717:Sesquiterpenes; D013729:Terpenes / Q000378:metabolism* / Q000494:pharmacology; D000094162:Phytoalexins
chemical_list: D053138:Cyclohexenes; D009822:Oils, Volatile; D012717:Sesquiterpenes; D013729:Terpenes; D000077222:Limonene; D006861:Hydrogen Peroxide; D000094162:Phytoalexins