Herbivore Oral Secretions are the First Line of Protection Against Plant-Induced Defences

In order to mount a successful defense, plants must specifically recognize the threat (microbe vs. herbivore), elicit the appropriate signaling pathway (e.g., salicylic acid vs. jasmonic acid) and mount the proper defense. As effective counterploys, herbivores may disrupt defense signaling to suppress defenses, detoxify defenses, or even sequester these defenses in their bodies to avoid toxicity. Our current research has focused on salivary effectors that disrupt plant defense signaling. Our hypothesis is that as an alternative counterploy, some herbivores may present themselves in "disguise" and thus avoid proper detection. We believe this alternative counterploy has been overlooked, but may represent a commonly used strategy by certain herbivores. Emerging evidence suggest that some herbivores may actively deposit microbes in their oral secretions on plants, and thus be "mistakenly" recognized as microbes. Consequently, plants turn on the incorrect signaling pathway and express defenses that are ineffective against these intruders.