Potential for the use of elicitors of plant resistance in arthropod management programs

Abstract

Plants protect themselves from arthropod herbivores both directly, by expressing biochemical and morphological traits that interfere with herbivore development or behavior, and indirectly, by facilitating the action of natural enemies of herbivores. These direct and indirect resistance mechanisms are not always expressed at maximal levels by plants, but rather can be induced to higher levels by a variety of stimuli, most notably prior herbivory. The recent discovery of chemical elicitors of induced responses has led to interest in manipulating the inducible responses of plants for crop protection. Applications of elicitors of induced responses made at appropriate times during the growing season of a crop have the potential of activating both direct and indirect mechanisms of plant resistance and thereby simultaneously augmenting host-plant resistance and biological control. This strategy may serve as an important component of a multifaceted, ecologically-based pest management program and is unlikely to precipitate the rapid evolution of countermeasures by target pests. However, this strategy will not be appropriate in all crops or against all arthropod pests. The conditions under which the use of an elicitor is likely to be successful are discussed, and examples of the successful use of elicitors are reviewed.

Less is More: Treatment with BTH and Laminarin Reduces Herbivore-Induced Volatile Emissions in Maize but Increases Parasitoid Attraction

“…Therefore, protecting crops against diseases by using Laminarin and BTH could lead to a potential conflict, as both elicitors activate defenses against pathogens, but may weaken plant resistance against certain herbivores (Heil and Bostock, 2002;Stout et al, 2002;Taylor et al, 2004;Bostock, 2005;Beckers and Spoel, 2006). Our data suggest, however, that these potential negative effects of plant strengtheners may be outweighed by their positive effect on multitrophic interactions: BTH and Laminarin treated plants are likely to become more attractive to a wide variety of parasitoids after herbivore attack, and furthermore, through the suppression of the dominating plant volatiles, treated plants may be less apparent to herbivores that use HIPVs for host location (Halitschke et al, 2008).…”

Prospects for plant defence activators and biocontrol in IPM – Concepts and lessons learnt so far

“…They have been proposed as potential tools for use within integrated 65 pest management (IPM) strategies that aim to minimise the use of toxic products (Stout et al, 2002; 66 Vallad and Goodman, 2004). A key advantage of plant activators, compared to broad spectrum 67 toxicants, is that they are compatible with biocontrol agents and can even promote plant 68 attractiveness to natural enemies of plant pests (Stout et al, 2002, Bruce 2010.…”

“…They have been proposed as potential tools for use within integrated 65 pest management (IPM) strategies that aim to minimise the use of toxic products (Stout et al, 2002; 66 Vallad and Goodman, 2004). A key advantage of plant activators, compared to broad spectrum 67 toxicants, is that they are compatible with biocontrol agents and can even promote plant 68 attractiveness to natural enemies of plant pests (Stout et al, 2002, Bruce 2010. Another advantage 69 is that induced resistance via priming is based on an augmentation of basal defence resistance 70 (Ahmad et al, 2010) and is controlled by a large number of defence related plant genes (also 71 C 72 resistance is a durable form of disease protection, since the augmentation of multigenic resistance is 73 difficult to break by pathogens (Gardner et al, 1999;Ahmad et al, 2010).…”

Host Plant Resistance for the Management of Bemisia tabaci: A Multi-crop Survey with Emphasis on Tomato

“…However, induced resistance is acquired in plants after being attacked in such a way that in many instances if a plant survives an attack, it defends itself much better from a later attack from the same organism or even other organisms. Inducible responses are thought to be a means of avoiding costs associated with constitutively expressed resistance mechanism (Stout et al 2002).…”