Plant Responses to Insect Egg Deposition

Abstract

Plants can respond to insect egg deposition and thus resist attack by herbivorous insects from the beginning of the attack, egg deposition. We review ecological effects of plant responses to insect eggs and differentiate between egg-induced plant defenses that directly harm the eggs and indirect defenses that involve egg parasitoids. Furthermore, we discuss the ability of plants to take insect eggs as warning signals; the eggs indicate future larval feeding damage and trigger plant changes that either directly impair larval performance or attract enemies of the larvae. We address the questions of how egg-associated cues elicit plant defenses, how the information that eggs have been laid is transmitted within a plant, and which molecular and chemical plant responses are induced by egg deposition. Finally, we highlight evolutionary aspects of the interactions between plants and insect eggs and ask how the herbivorous insect copes with egg-induced plant defenses and may avoid them by counteradaptations.

Arabidopsis MYC Transcription Factors Are the Target of Hormonal Salicylic Acid/Jasmonic Acid Cross Talk in Response to Pieris brassicae Egg Extract

“…Evidence has accumulated that plants can recognize and respond to oviposition by inducing direct and indirect defenses (Hilker and Fatouros, 2015;Reymond, 2013). In Arabidopsis, insect eggs trigger cellular and molecular changes that are very similar to those that are caused by infection with biotroph pathogens.…”

Antibiosis resistance against larval cabbage root fly, Delia radicum, in wild Brassica-species

“…Recent studies showed that herbivore eggs affect plant direct and indirect defence (Hilker and Fatouros 2015). Although in nature D. radicum lays its eggs not directly in contact with the plant (Zohren 1968cited in Schoonhoven et al 2005, root exudates contain secondary metabolites (Schreiner et al 2011) that could potentially influence egg development and survival.…”

A comparison of plants and animals in their responses to risk of consumption

“…The herbivore chemicals that elicit recognition by plants are essential components that attackers cannot easily change or do without, such as those used in nitrogen metabolism [19]. Many plants also recognize fluids associated with insect eggs (pre-consumptive, direct herbivore cues) [20,21 ] and even herbivore mating pheromones [22]. Since plants respond more slowly than animals, early recognition may allow plants to mount defenses before actually losing tissue, since eggs and mating pheromone should be reliable cues that feeding herbivores are in a plant's immediate future.…”