scholarly journals Volatiles Emission by Crotalaria nitens after Insect Attack

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6941
Author(s):  
Fausto Prada ◽  
Elena E. Stashenko ◽  
Jairo René Martínez

Plants are known to increase the emission of volatile organic compounds upon the damage of phytophagous insects. However, very little is known about the composition and temporal dynamics of volatiles released by wild plants of the genus Crotalaria (Fabaceae) attacked with the specialist lepidopteran caterpillar Utetheisa ornatrix (Linnaeus) (Erebidae). In this work, the herbivore-induced plant volatiles (HIPV) emitted by Crotalaria nitens Kunth plants were isolated with solid phase micro-extraction and the conventional purge and trap technique, and their identification was carried out by GC/MS. The poly-dimethylsiloxane/divinylbenzene fiber showed higher affinity for the extraction of apolar compounds (e.g., trans-β-caryophyllene) compared to the Porapak™-Q adsorbent from the purge & trap method that extracted more polar compounds (e.g., trans-nerolidol and indole). The compounds emitted by C. nitens were mainly green leaf volatile substances, terpenoids, aromatics, and aldoximes (isobutyraldoxime and 2-methylbutyraldoxime), whose maximum emission was six hours after the attack. The attack by caterpillars significantly increased the volatile compounds emission in the C. nitens leaves compared to those subjected to mechanical damage. This result indicated that the U. ornatrix caterpillar is responsible for generating a specific response in C. nitens plants. It was demonstrated that HIPVs repelled conspecific moths from attacked plants and favored oviposition in those without damage. The results showed the importance of volatiles in plant–insect interactions, as well as the choice of appropriate extraction and analytical methods for their study.

2007 ◽  
Vol 20 (6) ◽  
pp. 707-716 ◽  
Author(s):  
Jürgen Engelberth ◽  
Irmgard Seidl-Adams ◽  
Jack C. Schultz ◽  
James H. Tumlinson

The induction of jasmonic acid (JA) is one of the major signaling events in plants in response to insect herbivore damage and leads to the activation of direct and indirect defensive measures. Green leafy volatiles, which constitute a major portion of volatile organic compounds, often are released in response to insect herbivore attack and have been shown to significantly activate JA production in exposed corn (Zea mays) seedlings, thereby priming these plants specifically against subsequent herbivore attack. To explore the factors determining the specificity of the octadecanoid signaling pathway in corn, we analyzed qualitative and quantitative changes in major octadecanoids. The time course and the amount of induced JA and 12-oxophytodienoic acid levels in corn seedlings were strikingly different after wounding, application of caterpillar regurgitant, or treatment with cis-3-hexenyl acetate (Z-3-6:AC). Exposure to Z-3-6:AC induced accumulation of transcripts encoded by three putative 12-oxophytodienoate10,11-re-ductase genes (ZmOPR1/2, ZmOPR5, and ZmOPR8). Although changes in ZmOPR5 RNAs were detected only after exposure to Z-3-6:AC, ZmOPR1/2 RNAs and ZmOPR8 RNAs also were abundant after treatment with crude regurgitant elicitor or mechanical damage. The physiological implications of these findings in the context of plant-insect interactions are discussed.


2019 ◽  
Vol 3 (6) ◽  
pp. 723-729
Author(s):  
Roslyn Gleadow ◽  
Jim Hanan ◽  
Alan Dorin

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.


Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 134
Author(s):  
Marília Elias Gallon ◽  
Leonardo Gobbo-Neto

Balanced nutritional intake is essential to ensure that insects undergo adequate larval development and metamorphosis. Integrative multidisciplinary approaches have contributed valuable insights regarding the ecological and evolutionary outcomes of plant–insect interactions. To address the plant metabolites involved in the larval development of a specialist insect, we investigated the development of Chlosyne lacinia caterpillars fed on Heliantheae species (Tithonia diversifolia, Tridax procumbens and Aldama robusta) leaves and determined the chemical profile of plants and insects using a metabolomic approach. By means of LC-MS and GC-MS combined analyses, 51 metabolites were putatively identified in Heliantheae species and C. lacinia caterpillars and frass; these metabolites included flavonoids, sesquiterpene lactones, monoterpenoids, sesquiterpenoids, diterpenes, triterpenes, oxygenated terpene derivatives, steroids and lipid derivatives. The leading discriminant metabolites were diterpenes, which were detected only in A. robusta leaves and insects that were fed on this plant-based diet. Additionally, caterpillars fed on A. robusta leaves took longer to complete their development to the adult phase and exhibited a greater diapause rate. Hence, we hypothesized that diterpenes may be involved in the differential larval development. Our findings shed light on the plant metabolites that play roles in insect development and metabolism, opening new research avenues for integrative studies of insect nutritional ecology.


2017 ◽  
Vol 11 (2) ◽  
pp. 152-161 ◽  
Author(s):  
Corinna Rickert ◽  
Andreas Fichtner ◽  
Roel van Klink

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