Jasmonic acid-induced volatiles of Brassica oleracea attract parasitoids: effects of time and dose, and comparison with induction by herbivores

Abstract

Caterpillar feeding induces direct and indirect defences in brassicaceous plants. This study focused on the role of the octadecanoid pathway in induced indirect defence in Brassica oleracea. The effect of induction by exogenous application of jasmonic acid (JA) on the responses of Brussels sprouts plants and on host-location behaviour of associated parasitoid wasps was studied. Feeding by the biting–chewing herbivores Pieris rapae and Plutella xylostella resulted in significantly increased endogenous levels of JA, a central component in the octadecanoid signalling pathway that mediates induced plant defence. The levels of the intermediate 12-oxophyto-dienoic acid (OPDA) were significantly induced only after P. rapae feeding. Three species of parasitoid wasps, Cotesia glomerata, C. rubecula, and Diadegma semiclausum, differing in host range and host specificity, were tested for their behavioural responses to volatiles from herbivore-induced, JA-induced, and non-induced plants. All three species were attracted to volatiles from JA-induced plants compared with control plants; however, they preferred volatiles from herbivore-induced plants over volatiles from JA-induced plants. Attraction of C. glomerata depended on both timing and dose of JA application. JA-induced plants produced larger quantities of volatiles than herbivore-induced and control plants, indicating that not only quantity, but also quality of the volatile blend is important in the host-location behaviour of the wasps.

Mechanisms and ecological implications of plant‐mediated interactions between belowground and aboveground insect herbivores

“…For a part, this may be due to different experimental approaches used, such as application of phytohormones to simulate herbivory versus real herbivory. Although phytohormones are commonly used to simulate herbivory and the defense responses they elicit are broadly similar to those induced by real herbivory (Baldwin 1990;Dicke and Vet 1999;Loivama¨ki et al 2004;Bruinsma et al 2008), some differences may still occur (Bruinsma et al 2009;van Dam et al 2010). Moreover, as there are differences in the temporal dynamics between response levels within a plant, the link between the mechanisms and the ecological consequences of BG-AG interactions may be missed when focusing only on one response level or one time point.…”

Defence mechanisms of Brassicaceae: implications for plant-insect interactions and potential for integrated pest management. A review

“…Cotesia plutellae Kurdjumov is a dominant solitary koinobiont, larval endoparasitoid of P. xylostella, and generally regarded as being highly specific to P. xylostella (Talekar and Shelton, 1993;Agelopoulos and Keller, 1994a-c;Geervliet et al, 1994Geervliet et al, , 1998Mattiacci et al, 1994Mattiacci et al, , 2001Harvey et al, 2003;Fatouros et al, 2005b). Diadegma semiclausum Hellén is a specialised parasitoid of P. xylostella (Bruinsma et al, 2009). Platygaster subuliformis Kieffer and Omphale clypealis Thompson are among the more than 20 species of hymenopteran parasitoids that attack D. brassicae (Murchie et al, 1997).…”

“…Such indirect interactions between host and non-host herbivores are referred to as infochemical-mediated indirect interactions. In a recent study, Bruinsma et al (2009) showed that feeding by P. rapae and P. xylostella resulted in increased endogenous levels of jasmonic acid in B. oleracea (Brussels sprouts) plants. However, the levels of the intermediate 12-oxophyto-dienoic acid (OPDA) were induced only after P. rapae feeding.…”

“…However, the levels of the intermediate 12-oxophyto-dienoic acid (OPDA) were induced only after P. rapae feeding. Moreover, jasmonic acid-induced volatiles of B. oleracea attracted parasitoids (C. glomerata, C. rubecula and D. semiclausum) in a time-and dose-dependent application (Bruinsma et al, 2009). In a study using two insects, the peach aphid (M. persicae) and the caterpillar (P. xylostella) on cabbage plants, Agbogba and Powell (2007) looked at the responses of the aphid parasitoid D. rapae by Y-tube olfactometry.…”

Plants under dual attack : consequences for plant chemistry and parasitoid behavior

“…to what benefit would a plant emit volatiles that carnivorous arthropods would misinterpret. While herbivory does indeed elicit a volatile response which can then serve as cues for foraging natural enemies, volatile emissions can be induced by a multitude of stimuli, from abiotic and other biotic stresses that include pathogen infection, and also by exogenous application of phytohormones to plants (Bruinsma et al, 2009;Holopainen & Gershenzon, 2010). All these stressors induce volatile induction via the same general pathways, though there is a degree of attacker specificity in the phytohormonal 'signal signature' (De Vos et al, 2005;Tumlinson & Engelberth, 2008).…”