Plant Interactions with Multiple Insect Herbivores: From Community to Genes

Abstract

Every plant is a member of a complex insect community that consists of tens to hundreds of species that belong to different trophic levels. The dynamics of this community are critically influenced by the plant, which mediates interactions between community members that can occur on the plant simultaneously or at different times. Herbivory results in changes in the plant's morphological or chemical phenotype that affect interactions with subsequently arriving herbivores. Changes in the plant's phenotype are mediated by molecular processes such as phytohormonal signaling networks and transcriptomic rearrangements that are initiated by oral secretions of the herbivore. Processes at different levels of biological complexity occur at timescales ranging from minutes to years. In this review, we address plant-mediated interactions with multiple species of the associated insect community and their effects on community dynamics, and link these to the mechanistic effects that multiple attacks have on plant phenotypes.

Influence of drought on plant performance through changes in belowground tritrophic interactions

“…Interactions between soil moisture, plants, herbivores and natural enemies are expected to depend on a number of factors, including (a) the range of soil moisture levels (Aslam, Johnson, & Karley, 2013; Mahmoud et al., 2016; Schmitz & Barton, 2014), (b) the timing of changes in soil moisture relative to the development of all three trophic levels (Rosenblatt & Schmitz, 2016; Schmitz & Barton, 2014; Wade, Karley, Johnson, Hartley, & Bell, 2017) (c) the plant genotype (Stam et al., 2014), (d) the severity of herbivore attack (Soler, Bezemer, van der Putten, Vet, & Harvey, 2005) and (e) the abundance and diversity of herbivore natural enemies (Erb & Lu, 2013; Thomson, Macfadyen, & Hoffmann, 2010). Our study was conducted at low soil moisture close to the plant's wilting point, relatively low WCR infestation levels and a relatively short period between the application of EPNs and plant performance measurements.…”

Comparative analyses of transcriptome and proteome in response to cotton bollworm between a resistant wild soybean and a susceptible soybean cultivar

“…JA positively regulated a series of genes conferring resistance to herbivory insects, whereas ET and SA mainly functioned as negative regulators, which have antagonistic effects on JA-dependent responses (Wu and Baldwin 2009). In addition to JA, ET and SA, other phytohormones such as abscisic acid (ABA), auxin, cytokinin and gibberellins, are also involved in herbivore-induced responses (Gatehouse 2002;Stam et al 2014). In addition to phytohormones, anti-herbivore secondary metabolites such as phenylpropanoids, glucosinolates, alkaloids and phenolics, also had important functions in conferring resistance to herbivores in plants (Wu and Baldwin 2009).…”

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

“…Multiple herbivores can co-occur on the same plant, and can be separated spatially or temporally, while plant pathogens represent another class of ubiquitous attackers. There has been increasing focus on the effects of multiple stress on the performance and preference of associated insect community members, notably in the Brassicaceae (Stam et al, 2014), yet induced VOC emissions have been extensively studied primarily in response to individual abiotic or biotic stress, with little known of the mechanisms of VOC induction during dual stress. However, as the effects of multiple stress are expressed at the molecular level, it is expected that plant defense responses can be affected at other levels as well, such as induced volatile production, and lead to changes in plant interactions with their community members ).…”

“…While the direct effects of multiple attack on herbivore life-history parameters and behavior have been investigated in detail (For reviews see Denno et al, 1995;Kaplan & Denno, 2007;Stam et al, 2014), to date comparatively fewer studies have investigated HIPVs and the ensuing effects on tritrophic interactions in the context of multiple herbivore attack (Shiojiri et al, 2001;Rodriguez-Saona et al, 2003;Zhang et al, 2009;Erb et al, 2010;Hare & Sun, 2011). Insects are not the sole organisms to attack plants; plant pathogens also commonly infect plants, yet little attention has been paid to the effects of plant pathogen infection on tritrophic interactions despite the strong prevalence of pathogens in natural systems, frequently co-occurring with herbivory (Tack & Dicke, 2013).…”

“…However, these chemical cues can be exploited by members of a different species, for instance to locate prey (Wyatt, 2003). This makes chemical information an important element in structuring individual behavior and the interactions between community members (Vet, 1996;Stam et al, 2014). Volatile chemicals emitted by plants have a wide range of functions, such as plant-toplant signals, defense chemicals or pollinator attractants (Holopainen, 2004;Peñuelas & Llusià, 2004;Heil & Karban, 2010), and so a volatile blend can have different meanings for different organisms.…”