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The occurrence of monoterpenes and sesquiterpenes (red lines), cyanogenic glycosides (blue lines), and iridoids (yellow lines) in the plant kingdom (a) and in arthropods (b). Dashed lines indicate when it is not clear whether metabolites present in insects are produced de novo or not. Terpenes are widespread throughout the seed and nonseed plants, and are also produced by insect species belonging to different orders. Cyanogenic glycosides seem to be restricted to seed plants and ferns and are synthesized by millipede and moth species, and possibly also by beetles and true bugs. Iridoids have been detected in angiosperms. In insects, iridoids are found in beetles and aphids.
Source publication
Despite the phylogenetic distance between plants and insects, these two groups of organisms produce some secondary metabolites in common. Identical structures belonging to chemical classes such as the simple monoterpenes and sesquiterpenes, iridoid monoterpenes, cyanogenic glycosides, benzoic acid derivatives, benzoquinones and naphthoquinones are...
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A major hypothesis for the evolution of chemical signals is that pheromones arise from non-communicative precursor compounds. However, data supporting this hypothesis are rare, primarily because the original functions of the antecedent compounds often have been lost. A notable exception, however, is the parasitoid wasp species Leptopilina heterotom...
Citations
... For example, species of the genus Nepeta produce NON, while Catharanthus roseus is capable of NOL production through the seco-iridoid pathway (Formisano et al., 2011;Miettinen et al., 2014). Terpene production in both plants and insects starts with isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are derived from the cytosolic mevalonate pathway (MVA) or the plastidial methylerythritol phosphate pathway (MEP) (Beran et al., 2019;Yang et al., 2012). The first step in NOL biosynthesis ( Figure 1) is the condensation of IPP and DMAPP into geranyl diphosphate (GPP) by an isoprenyl diphosphate synthase (IDS): GPP synthase F I G U R E 1 NOL biosynthetic pathway. ...
Aphids cause massive agricultural losses through direct damage or as pathogen vectors. Control often relies on insecticides, which are expensive and not selective. An interesting alternative is to use aphid sex pheromones nepetalactone (NON) and nepetalactol (NOL) to interfere with aphid mating or attract aphid predators. Here, we explore production of these compounds in plants, as their precursors can be derived from mevalonate (MVA) and methylerythritol phosphate (MEP) pathways. By introducing six genes, including a major latex protein‐like (MLPL) enzyme, we engineered a functional nepetalactol biosynthetic pathway into plants. Transient expression of these enzymes in N. benthamiana caused production of nepetalactone, without the need for external supplementation with substrates. Targeting all six enzymes into the chloroplast appeared to result in higher NON yields than just chloroplast‐targeting the first two enzymes. We could not detect NOL, suggesting it is rapidly oxidised to NON. In addition, we produced NON in stably transformed Camelina sativa (Camelina) lines. Interestingly, the specific NON enantiomer was different in N. benthamiana compared to in Camelina, indicating the value of different platforms for producing specific isoforms. This opens possibilities for using plants as green factories of pheromones for baits or as pheromone dispensers that interfere with insect behaviour.
... In 1962, it lost the FDA's approval owing to efficacy concerns [30,41]; it was approved again as ycanth (cantharidin), becoming the first FDA-approved treatment for Molluscum [42]. Today, cantharidin analogs (26)(27)(28)(29)(30) have an enormous interest in deciphering its toxicities [43], anticancer activities [44], protein phosphatases pharmacogenomics [29,45,46], structural-activity relationships [44,47], and novel strategies like combination therapies are explored and study [43,44,48]. Norcantharidin 26, a demethylated analog of cantharidin, is reported to attenuate renal tubulointerstitial fibrosis, an inevitable consequence of chronic kidney disease. ...
Background
The recent FDA-approved Ycanth (cantharidin) for treating Molluscum contagiosum , a viral skin infection, was first reported from blister beetles. Medicinal insects are reservoirs for exploring bioactive molecules, which have various benefits. Their use in traditional medicinal practices explains why uncovering new chemical substances is worthwhile.
Main body of the abstract
Insect-derived natural products with diverse and unique structures are significant for drug discovery and development potential. Various natural products are reported from insect sources; in this context, it also emphasizes the importance of active global participation among researchers, as it offers significant potential for developing a sustainable approach to why this should not remain untouched for ever-increasing unmet challenges.
Conclusion
Hence, practitioners in natural product chemistry and allied disciplines have a role in understating the enormous potential of discovering bioactive metabolites for their medicinal value to human health.
... By occupying analogous ecological niches, these species develop traits and compounds that enhance their survival in comparable environments. Different species can produce similar metabolites because they often conserve the biosynthetic pathways for metabolite production within their taxonomic groups [71][72][73][74]. ...
Agricultural pests present a significant challenge to humanity, often managed through synthetic chemicals that, when misused, can cause irreversible harm to both the environment and human health. This study focuses on endemic plants from the Yucatán Peninsula in Mexico, particularly from the state of Campeche, to identify their historical uses and propose an updated list of species with pesticide potential in the region. We systematically reviewed specimens from the Center for Sustainable Development and Wildlife Management (CEDESU) herbarium and local databases. Of the 3084 specimens collected, 2524 (81.84%) were from Campeche. The collection encompasses 106 botanical families, 459 genera, and 747 species. The study identified 201 plant species from 48 taxonomic families that are endemic to the Yucatán Peninsula Biotic Province (YPBP), of which 123 species are exclusive to the Mexican Yucatán Peninsula (MYP), representing 61.19% of the endemic species. Campeche contains 134 species (66.66%), distributed across 96 genera and 43 families. Notably, 46.26% of the species (62 species) belong to the Mexican region, with 8 species (12.90%) exclusive to Campeche. The research revealed that 27.90% of the families and 19.79% of the genera present in the state have been the subject of previous scientific studies regarding their use as pesticides. The most extensively studied families were Euphorbiaceae and Fabaceae. However, there is a notable lack of research on endemic plants from the Yucatán Peninsula, underscoring the need for increased attention to these species. The identified genera and families contain chemical compounds with activity against significant pests, demonstrating substantial potential for the development of natural pesticides.
... 35 Some act by interfering with the intake of nutrients by insects, some disrupt the digestion and absorption of insect intestines, and some can directly poison the insect pests. [36][37][38][39][40][41][42] Beneficial microorganisms can enhance plant resistance to insects by promoting the production of insect resistant metabolites. For example, inoculation of Pseudomonas spp. ...
BACKGROUND
Epichloë endophytes provide many benefits to host plants, including enhanced insect resistance. Fungal alkaloids are usually thought to be responsible for the endophyte‐conferred herbivore resistance. Nonetheless, the fungal alkaloid profiles and concentrations may vary considerably among grass–endophyte systems. This indicates that apart from fungal alkaloids, additional mechanisms such as endophyte‐mediated host defense are likely contributed to endophyte–grass–insect interactions. In this study, we addressed this issue by investigating the effect of Epichloë on the defense responses of Achnatherum sibiricum against locusts.
RESULTS
The results showed that Epichloë endophytes increased locust resistance of A. sibiricum in both choice and non‐choice feeding experiments. In no feeding groups, endophyte infection increased the content of jasmonic acid (JA) and ethylene (ET), chitinase activity, and the biosynthetic gene expression of the relevant pathways. Endophyte infection also increased the content of total phenolics and condensed tannins. These indicators were negatively correlated with leaf consumption. In locust feeding groups, endophyte infection increased trypsin inhibitor activity. Exogenous application of phytohormones further proved that JA and ET reduced the consumption of A. sibiricum by locusts.
CONCLUSION
The present study showed that endophyte‐conferred host defense was mainly constitutive, that is, the defense characteristics of host plants were mainly manifested in no feeding groups. Endophyte presence enhanced locust resistance of the host by activating the JA/ET signaling pathway, elevating chitinase activity and phenolic compounds content, thereby improving the defense ability of host plants. © 2024 Society of Chemical Industry.
... However, there was no common pattern regarding the timescale of gene family evolution related to plant metabolites. This variability could be explained by the different environments in which plants live and the diverse ecological functions of plant metabolites, such as attracting pollinators and resisting biotic and abiotic environmental stressors 54 . Furthermore, no similar timescale phenomena were observed for genes associated with plant metabolite resistance to insects; however, such a phenomenon was noted for rye Pm3-and wheat Pm8-like genes, which are related to pathogen resistance 55 . ...
Asparagales, the largest monocot order, is renowned for its ecological, economic, and medicinal significance. Here, we leverage transcriptome data from 455 Asparagales species to explore the phylogeny of Asparagales. Moreover, we investigate the evolutionary patterns of the genes involved in allium flavor formation. We not only establish a robust bifurcating phylogeny of Asparagales but also explore their reticulate relationships. Notably, we find that eight genes involved in the biosynthesis of allium flavor compounds underwent expansion in Allium species. Furthermore, we observe Allium-specific mutations in one amino acid within alliinase and three within lachrymatory factor synthase. Overall, our findings highlight the role of gene expansion, increased expression, and amino acid mutations in driving the evolution of Allium-specific compounds. These insights not only deepen our understanding of the phylogeny of Asparagales but also illuminate the genetic mechanisms underpinning specialized compounds.
... Although these compounds are not essential to the life cycle of plants, they play a significant role in plant-environment interaction (Isah, 2019). They act in defence against competitors, herbivory and pathogens, as well as serving as attractants or repellents, characteristics of great agronomic interest (Castro et al., 2005;Tiilikkala;Fagernäs;Tiilikkala, 2010;Verruck;Prudencio;Da Silveira, 2018;Beran; Kollner; Gershenzon, 2019). ...
Liriomyza sativa is a cosmopolitan and polyphagous insect, a key pest of crops such as tomato and melon. The inadequacy of insecticide application techniques has developed resistant populations. The objective of this research was to evaluate the toxicity, insecticidal activity and deterrence of pyroligneous extracts on the leafminer fly. The experiments were carried out under laboratory conditions of 25 ± 2°C and humidity of 60 ± 10%. For the toxicity test, solutions were prepared in different concentrations by diluting them in distilled water. Leaf discs containing L. sativae larvae were immersed in the solutions. For insecticidal activity and deterrence tests, jack bean plants were subjected to application of treatments using an airbrush, spraying 6 mL of the solutions on each plant. All extracts showed significant mortality for the larvae, with emphasis on the pyroligneous extract of coffee straw at 350ºC. The extracts did not interfere with the other developmental stages of the leafminer fly. The pyroligneous extract from the commercial company Agttec and the coffee straw extract at 600ºC were classified as attractive and the coffee straw extract at 350ºC as detergent. It is concluded that pyroligneous extracts can be used in the management of L. sativae.
... Plants are sessile organisms that are constantly threatened by herbivores; therefore, they have evolved multiple strategies to defend themselves, including direct and indirect defences (Alamgir et al. 2016;Hervé and Erb 2019). Direct defences involve the use of physical structures or toxic compounds to deter feeding or alter the physiology of herbivores (Beran et al. 2019;Hussain et al. 2019). Indirect defences involve the attraction of natural enemies of the herbivores, such as via the production of volatile organic compounds (VOCs) (Turlings and Erb 2018;Sun et al. 2022). ...
Plants can perceive and respond to external stimuli by activating both direct and indirect defences against herbivores. Soil‐dwelling entomopathogenic nematodes (EPNs), natural enemies of root‐feeding herbivores, carry symbiotic bacteria that grow and reproduce once inside arthropod hosts. We hypothesized that the metabolites produced by EPN‐infected insect cadavers could be perceived by plants, thereby activating plant defences systemically. We tested this hypothesis by adding three EPN‐infected Galleria mellonella cadavers to maize plants and testing plant responses against a major maize pest ( Spodoptera frugiperda ) and one of its parasitoids ( Trichogramma dendrolimi ). We found that S. frugiperda females deposited fewer, and caterpillars fed less on maize plants growing near EPN‐infected cadavers than on control plants. Accordingly, EPN‐infected cadavers triggered the systemic accumulation of defence hormones (SA), genes ( PR1 ), and enzymes (SOD, POD, and CAT) in maize leaves. Furthermore, four volatile organic compounds produced by plants exposed to EPN‐infected cadavers deterred S. frugiperda caterpillars and female adults. However, these compounds were more attractive to T. dendrolimi parasitoids. Our study enhances the understanding of the intricate relationships within the above‐ and belowground ecosystems and provides crucial insights for advancing sustainable pest management strategies.
... This distinction in EO chemodiversity suggests the presence of unique biosynthetic mechanisms regulated by "promiscuous enzymes" in metabolic pathways of each plant organ [4,[74][75][76]. As a result, a relevant variety of odoriferous substances is biosynthesized. ...
... As a result, a relevant variety of odoriferous substances is biosynthesized. This complex system is notoriously understood to be controlled by widely studied enzyme superfamilies called terpene synthases (TPS) [4,[74][75][76]. Through their activity, an intricate network of mono-and sesquiterpenes can be formed, generating a universe of aromas that play critical roles in plant communication. ...
... Through their activity, an intricate network of mono-and sesquiterpenes can be formed, generating a universe of aromas that play critical roles in plant communication. TPS are even distinguished at phylogenetic levels, being a major theme in chemotaxonomy [4,37,[74][75][76][77], and are subjected to years of pressures, selective bottlenecks, and adaptations and mediated by various biotic and abiotic factors [4,37,[74][75][76][77]. ...
Piper mollicomum Kunth (Piperaceae) plays a vital role in the preservation of the Brazilian Atlantic Forest by contributing to the regeneration of deforested areas. Recent scientific investigations have analyzed the chemical constituents and seasonal dynamics of essential oils (EO) from various Piper L. species, highlighting the need to elucidate their chemical–ecological interactions. This study aims to expand the chemical–ecological knowledge of this important taxon in neotropical forests, using P. mollicomum as a model. The methodologies employed include the collection of plant material, EO extraction by hydrodistillation, analysis of EO by gas chromatography–mass spectrometry (GC–MS) and gas chromatography–flame ionization detector (GC–FID), recording the frequency of visits by potential pollinators and microclimatic variables, and by conducting calculations of chemodiversity and chemophenetic indices. Chemical analyses indicated that the diversity of EO and environmental factors are linked to the activities of potential pollinators. In the Tijuca Forest, P. mollicomum revealed significant interactions between its volatile constituents and microclimatic variables, showing that the chemodiversity of the leaves and reproductive organs correlates with pollinator visitation. Additionally, a notable difference in chemical evenness was observed between these vegetative structures. The chemophenetic indices by Ramos and Moreira also revealed correlations with chemical diversity.
... However, detoxification or excretion are also possible strategies [6]. Notably, herbivores and non-herbivores can synthesise de novo defence chemicals which are similar to those produced by plants ("convergent evolution") [7]. ...
Sawfly species of the genus Monophadnus are specialised on Ranunculaceae plants from which the larvae can sequester furostanol saponins into the haemolymph, mainly (25R)-26-[(α-L-rhamnopyranosyl)oxy]-22α-methoxyfurost-5-en-3β-yl-O-β-D-glucopyranosyl-(1→3)-O-[6-acetyl-β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranoside (compound 1). In this work, TLC, GC-MS, and HPLC-DAD-ESI/MS analyses together with feeding, repeated simulated attacks, and ant deterrence bioassays were conducted to extend the chemoecological knowledge about two sawfly species specialised on H. foetidus L. (Monophadnus species A) and H. viridis L. (Monophadnus species B). Larvae of Monophadnus species B were mostly feeding on the squares treated with the n-butanol fraction from H. foetidus, compound 1 being its primary non-nutritional stimulant. In contrast, all H. viridis fractions stimulated feeding, with n-hexane marginally more active. β-sitosterol within n-hexane was determined as the nutritional stimulant. Quantitative analyses demonstrated that leaves of H. viridis but not H. foetidus contain the ecdysteroids 20-hydroxyecdysone and polypodine B. Moreover, the haemolymph of Monophadnus species B larvae reared on H. viridis contained the glycosides of polypodine B and 20-hydroxyecdysone at a concentration of 2.5 to 6.8 µmol/g fresh weight of haemolymph. This concentration is several thousand times higher than the concentration range of the aglycones in their host plant (3.63 × 10−4 to 2.23 × 10−4 µmol total ecdysteroids/g fresh weight of leaves), suggesting bioaccumulation. The larvae of both species fed on H. foetidus do not show any traces of ecdysteroids in their haemolymph, indicating a facultative role of these compounds in their defence as well as their inability to endogenously synthesise these compounds. The haemolymph containing ecdysteroids was a significant feeding deterrent against Myrmica rubra L. ant workers (one of their natural predators) at 0.8 mg/mL. The larvae kept effective deterrent levels of glycosylated ecdysteroids (≅175 mM) between simulated attacks on days 1 and 2, but the levels clearly decreased on day 3 (≅75 mM). Most larvae (89%) survived a first attack but only 23% a consecutive second one. As a conclusion, we report for the first time that two Monophadnus species feeding on H. viridis sequester phytoecdysteroids into the larval haemolymph in the form of glycosides. In addition, compound 1 possesses defensive and phagostimulant activities, and we present evidence for a combined effect of furostanol saponins and ecdysteroids as repellents against ants.
... In Chapter 6, we investigated whether N. viridula-associated microbes were involved in the detoxification of NPA, eventually protecting the host. However, Beran et al. (2019) have recently described that insects have coevolved with their host plants, and themselves harbour a wealth of adaptations that allow them to feed on toxic plants. These resistance mechanisms include targetsite adaptations, inactivation via alkalization, rapid excretion, sequestration, degradation, and detoxification via cytochrome P450 monooxygenases, glutathione transferases and carboxylesterases (Li et al., 2007;Winde & Wittstock, 2011). ...
Throughout evolution, insects have developed exceptional adaptive capabilities by forming symbiotic relationships with microbes, which are often crucial for their survival. Among shield bugs, such as the Southern green shield bug Nezara viridula, mutualistic interactions with bacteria are common and contribute significantly to the insect’s ecological success. N. viridula is a piercing and sucking insect that relies on symbionts for nutrient supplementation. It is a highly invasive species with a broad dietary range across many plant families and its global spread results in significant agricultural losses. Recent studies showed that the shield bug microbiota can manipulate plant defences, affecting pest insect damage potential, however, the role of N. viridula microbiota remains unexplored. In this PhD thesis, the knowledge gaps in the insect-microbe symbiosis field were addressed and aimed to understand the role and relationship between N. viridula and its associated microbes. Our research revealed that N. viridula has a simple and stable microbiota which participates in digestion, nutrient provision, detoxification and repression of plant toxins which is detrimental to the development of sustainable pest control strategies. This study laid a solid foundation for future research in the area of insect-microbe interactions and their application for agricultural practices and pest management.
