Combined Transcript and Metabolite Analysis Reveals Genes Involved in Spider Mite Induced Volatile Formation in Cucumber Plants

Abstract

Many plants have an indirect defense against herbivores by emitting volatiles that attract carnivorous enemies of the herbivores. In cucumber (Cucumis sativus) the production of carnivore attractants can be induced by herbivory or jasmonic acid spraying. From the leaves of cucumber plants with and without spider mite infestation, two subtractive cDNA libraries were made that were enriched in cDNA fragments up-or down-regulated by spider mite infestation. A total of 713 randomly selected clones from these libraries were used to make a cDNA microarray. Subsequently, cucumber plants were sprayed with jasmonic acid, mechanically damaged, infested with spider mites, or left untreated (control). Leaf samples were taken at a range of different time points, and induced volatile compounds and mRNA (from the same leaves) were collected. cDNAs prepared from the mRNA were hybridized to the clones on the microarray. The resulting gene expression profiles were analyzed in combination with volatile production data in order to gain insight in the possible involvement of the studied genes in the synthesis of those volatiles. The clones on the microarray and the induced cucumber volatiles could be grouped into a number of clusters in which specific biosynthetic genes clustered with the product of that pathway. For example, lipoxygenase cDNA clones clustered with the volatile (Z)-3-hexenyl acetate and the volatile sesquiterpene (E,E)-a-farnesene clustered with an upregulated sesquiterpene synthase fragment. This fragment was used to screen a cDNA library which resulted in the cloning of the cucumber (E,E)-a-farnesene and (E)-b-caryophyllene synthases. The use of combined global gene expression analysis and metabolite analysis for the discovery of genes involved in specific biosynthetic processes is discussed.Plants have evolved the capacity to respond to herbivory with the production and emission of volatile compounds that attract predators of the herbivores (Dicke et al., 1990;Turlings et al., 1990). Thus, plants can defend themselves against herbivory not only by the use of direct defense (such as toxicity), but also by mobilizing carnivorous organisms in the surrounding environment (Turlings et al., 1995;Takabayashi and Dicke, 1996;De Moraes et al., 1998;Kessler and Baldwin, 2001). There is ample evidence that plants respond differently to mechanical damage than to herbivore feeding and that this is caused by elicitors released by the herbivore (e.g. Turlings et al., 1995;Takabayashi and Dicke, 1996;De Moraes et al., 1998;Van Poecke and Dicke, 2004). The many parameters that affect a plant's response to herbivory suggest the involvement of a sophisticated defense system that optimizes response depending on the intruding organism. The impact of individual compounds in a volatile blend emitted by herbivore-infested plants on predator behavior is difficult to investigate. Nevertheless, single compounds have in a number of cases been shown to attract predators (Dicke et al., 1990;Kessler and Baldwin, 2001), and careful exploitation...

Variation of Herbivore-Induced Volatile Terpenes among Arabidopsis Ecotypes Depends on Allelic Differences and Subcellular Targeting of Two Terpene Synthases, TPS02 and TPS03

“…S5). Several other TPSs producing (E)-b-ocimene or (E,E)-a-farnesene or both of these terpenes have been identified previously from gymnosperms (TPS-d; Martin et al, 2004) and in the TPS-a, -b, -f, and -g subfamilies of angiosperms (Dudareva et al, 2003;Arimura et al, 2004;Mercke et al, 2004;Nieuwenhuizen et al, 2009; Supplemental Fig. S5).…”

Can plants betray the presence of multiple herbivore species to predators and parasitoids? The role of learning in phytochemical information networks

“…Paré et al 1999;Bouwmeester et al 1999); (4) blends of HIPV not only emanate from the leaf under attack by the herbivore, but are also systemically induced in the plant (Turlings and Tumlinson 1992;Dicke 1994;Guerrieri et al 1999); (5) application of jasmonic acid (JA), a phytohormone, to wild-type plants or defence-signalling mutants leads to production of volatiles similar to HIPV (Hopke et al 1994;Ozawa et al 2000;Gols et al 2003;Thaler et al 2002;Van Poecke and Dicke 2003;Ament et al 2004); (6) herbivore-induced gene expression patterns in plants are similar to those mediated by jasmonates (e.g. Kant et al 2004;Ament et al 2004;Mercke et al 2004;Reymond et al 2004); (7) elicitors of HIPV synthesis in the plant have been found in the regurgitate/saliva of herbivores [N-(17-hydroxylinolenoyl)-L-glutamine or volicitin: Alborn et al 1997Alborn et al , 2000β-glucosidase: Hopke et al 1994;Mattiacci et al 1995]s.…”

Volatile terpenoids: multiple functions, biosynthesis, modulation and manipulation by genetic engineering

“…It has been demonstrated that upon herbivore attack, plants emit a blend of volatiles, which is composed of more than 200 compounds that are directly responsible for deterring, intoxicating or repelling herbivorous insects (Seybold et al 2006). Alternatively, they can attract the parasitoids and natural predators of offending herbivores, resulting in securing the plant from damage (Mercke et al 2004;Degen et al 2004;Dudareva et al 2013). The transformation of petunia with the (S)-limonene synthase gene from C. breweri results in linalool production that repels aphids (Lücker et al 2001).…”