Role of ethylene signaling in the production of rice volatiles induced by the rice brown planthopper Nilaparvata lugens

Abstract

Ethylene signaling pathway plays an important role in induced plant direct defense against herbivores and pathogens; however, up to now, only few researches have focused on its role in induced plant indirect defense, i.e. the release of herbivore-induced volatiles, and the results are variable. Using a model system consisting of rice plants, the rice brown planthopper Nilaparvata lugens and its egg parasitoid Anagrus nilaparvatae, we examined the role of ethylene signaling in the production of rice volatiles induced by N. lugens by measuring both the timing of herbivore-induced ethylene levels and the relationships between ethylene, rice volatiles and attraction of the parasitoid. N. lugens infestation significantly enhanced the release of ethylene during 2-24 h after infestation. Plants treated with ethephon, a compound that breaks down to release ethylene at cytoplasmic pH, released volatiles profiles similar to those released by N. lugens-infested plants, and both of them showed an equal attraction of the parasitoid. Moreover, pretreatment with 1-MCP, an inhibitor of ethylene perception, reduced the release of most of rice volatiles whose amount was enhanced by N. lugens infestation and decreased the attractiveness to the parasitoid. These results demonstrate that ethylene signaling is required for the production of rice volatiles induced by N. lugens.

Mechanisms of plant defense against insect herbivores

“…137 ET signaling pathway works either synergistically or antagonistically, 138 with JA in expression of plant defense responses against pathogens and herbivorous insects. It has been reported that ET and JA work together in tomato in PIs expression.…”

The prospect of applying chemical elicitors and plant strengtheners to enhance the biological control of crop pests

“…They used this approach on rice plants and developed a high-throughput chemical genetics screening system based on a herbivore-induced (S)-linalool synthase promoter fused to a b-glucuronidase reporter construct to test candidate synthetic compounds for their potential to induce rice defences. (S)-Linalool was chosen, because it is one of the key volatiles that is emitted by rice plants in response to attack by brown planthopper N. lugens [70][71][72][73][74] and is highly attractive to its main egg parasitoid Anagrus nilaparvatae [75]. Of the tested compounds, the widely used herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was found to be particularly active.…”

The Chloroplast-Localized Phospholipases D α4 and α5 Regulate Herbivore-Induced Direct and Indirect Defenses in Rice

“…The stems were harvested at 0, 1.5, and 3 h after SSB treatment, and JA and SA levels were analyzed by gas chromatography-mass spectrometry using labeled internal standards as described by Lou and Baldwin (2003). Plants were individually covered with a sealed glass cylinder (diameter, 4 cm; height, 50 cm), and ethylene production was determined using the same method as described by Lu et al (2006). Each treatment at each time interval was replicated five to six times.…”