Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/27/2017
Publication Date: 12/29/2017
Citation: Block, A.K., Christensen, S.A., Hunter III, C.T., Alborn, H.T. 2017. Herbivore derived fatty acid-amides elicit reactive oxygen species burst in plants. Journal of Experimental Botany. doi:10.1093/jxb/erx449.
Interpretive Summary: Insect pests such as caterpillars cause significant annual losses in crop production. Plants can recognize that they are attacked by caterpillar pests by detecting specific chemicals present in the spit of the caterpillars. This recognition allows the plants to marshal appropriate defense responses against the caterpillars. Understanding how plants translate this recognition into defense can guide crop breeding approaches aimed at maintaining and enhancing pest resistance. In this study Gainesville, Florida ARS Scientists show that recognition of the chemicals in caterpillar spit leads to the production of an oxidative compound called hydrogen peroxide in corn, tomato, tobacco and the model plant Arabidopsis. Furthermore we identify an enzyme involved in the production of this compound that is the same one used to produce hydrogen peroxide in response to infection with disease causing microbes. These results showed that this portion of the plant defense response is important for resistance to both insect and pathogen pests and it is therefore vital that breeding programs act to maintain it. Selecting germplasm that contains the ability to produce hydrogen peroxide during caterpillar attack could contribute to strategies that improve pest resistance in crop plants.
Technical Abstract: The formation of a reactive oxygen species (ROS) burst is a central response of plants to many forms of stress including pathogen attack, several abiotic stresses, damage and insect infestation. These ROS act as a direct defense as well as signaling and regulatory molecules. Perception of microbe or damage associated elicitors triggers an ROS burst in many plant species. In this study we show that the Lepidopteran derived fatty acid-amide elicitor N-linolenoyl-L-glutamine can induce an ROS burst in a diverse range of plants. Furthermore, in Arabidopsis this ROS burst was shown to be partially dependent on the plasma membrane localized NADPH oxidases RBOHD and RBOHF. Quantification of N-linolenoyl-L-glutamine induced ROS in phytohormone deficient tomato lines revealed that lack of jasmonic acid or salicylic acid but not ethylene, resulted in an enhanced ROS burst. Taken together, these data illustrate that perception of herbivore derived elicitors contributes to the ROS burst induced during herbivory and that this receptor-mediated response resembles that seen in microbe and damage associated pattern recognition in plants.