Cascading effects of caffeine intake by primary consumers to the upper trophic level

Author(s):  
Kévin Tougeron ◽  
Thierry Hance

Abstract Secondary metabolites are central to understanding the evolution of plant–animal interactions. Direct effects on phytophagous animals are well-known, but how secondary consumers adjust their behavioural and physiological responses to the herbivore's diet remains more scarcely explored for some metabolites. Caffeine is a neuroactive compound that affects both the behaviour and physiology of several animal species, from humans to insects. It is an alkaloid present in nectar, leaves and even sap of numerous species of plants where it plays a role in chemical defences against herbivores and pathogens. Caffeine effects have been overlooked in generalist herbivores that are not specialized in coffee or tea plants. Using a host–parasitoid system, we show that caffeine intake at a relatively low dose affects longevity and fecundity of the primary consumer, but also indirectly of the secondary one, suggesting that this alkaloid and/or its effects can be transmitted through trophic levels and persist in the food chain. Parasitism success was lowered by ≈16% on hosts fed with caffeine, and parasitoids of the next generation that have developed in hosts fed on caffeine showed a reduced longevity, but no differences in mass and size were found. This study helps at better understanding how plant secondary metabolites, such as caffeine involved in plant–animal interactions, could affect primary consumers, could have knock-on effects on upper trophic levels over generations, and could modify interspecific interactions in multitrophic systems.

2013 ◽  
Vol 30 (2) ◽  
pp. 97-109 ◽  
Author(s):  
Melanie Dammhahn ◽  
Steven M. Goodman

Abstract:Bats are important components in tropical mammal assemblages. Unravelling the mechanisms allowing multiple syntopic bat species to coexist can provide insights into community ecology. However, dietary information on component species of these assemblages is often difficult to obtain. Here we measured stable carbon and nitrogen isotopes in hair samples clipped from the backs of 94 specimens to indirectly examine whether trophic niche differentiation and microhabitat segregation explain the coexistence of 16 bat species at Ankarana, northern Madagascar. The assemblage ranged over 4.4‰ in δ15N and was structured into two trophic levels with phytophagous Pteropodidae as primary consumers (c. 3‰ enriched over plants) and different insectivorous bats as secondary consumers (c. 4‰ enriched over primary consumers). Bat species utilizing different microhabitats formed distinct isotopic clusters (metric analyses of δ13C–δ15N bi-plots), but taxa foraging in the same microhabitat did not show more pronounced trophic differentiation than those occupying different microhabitats. As revealed by multivariate analyses, no discernible feeding competition was found in the local assemblage amongst congeneric species as compared with non-congeners. In contrast to ecological niche theory, but in accordance with studies on New and Old World bat assemblages, competitive interactions appear to be relaxed at Ankarana and not a prevailing structuring force.


Ecology ◽  
2012 ◽  
Author(s):  
Lee A. Dyer

Trophic levels are determined by feeding relationships, with basal levels consisting of primary producers or detritus and upper levels based on consumption of these basal levels. Organisms on the second trophic level are referred to as primary consumers, which are in turn consumed by secondary consumers, and so on up a theoretical trophic chain. Primary consumers consist of herbivores and detritivores, while the third trophic level and those above include predators and parasites. Energy and matter move up trophic chains, and some compounds, including various toxins, may bioaccumulate at upper trophic levels. The concept of trophic level has generated a sizeable literature yielding useful ecological models, such as trophic cascades, and debates about top-down versus bottom-up regulation of herbivores. This article focuses on the contributions of the trophic-level concept to ecological theory, evolutionary biology, and the applied fields of agricultural and global change biology.


2020 ◽  
Author(s):  
Matthias Erb ◽  
Daniel J. Kliebenstein

The plant kingdom produces hundreds of thousands of small molecular weight organic compounds. Based on their assumed functions, the research community has classified them into three overarching groups: primary metabolites which are directly required for plant growth, secondary (or specialized) metabolites which mediate plant-environment interactions and hormones which regulate organismal processes, including metabolism. For decades, this functional trichotomy has shaped theory and experimentation in plant biology. However, evidence is accumulating that the boundaries between the different types of metabolites are blurred. An increasing number of mechanistic studies demonstrate that secondary metabolites are multifunctional and can act as potent regulators of plant growth and defense. Secondary metabolites are also re-integrated into primary metabolism, thus behaving like primary metabolites sensu lato. Several adaptive scenarios may have favored this functional diversity for secondary metabolites, including signaling robustness and cost-effective storage and recycling. Secondary metabolite multi-functionality can provide new explanations for ontogenetic patterns of defense production and can refine our understanding of plant-herbivore interactions, in particular by accounting for the discovery that adapted herbivores misuse plant secondary metabolites for multiple purposes, some of which mirror their functions in plants. In conclusion, recent work unveils the limits of our current classification system for plant metabolites and suggests that viewing them as integrated components of metabolic networks that are dynamically shaped by environmental selection pressures and transcend multiple trophic levels can improve our understanding of plant metabolism and plant-environment interactions.


Author(s):  
Minkyung Kim ◽  
Sojeong Lee ◽  
Hakyung Lee ◽  
Sangdon Lee

The response of the phenological events of individual species to climate change is not isolated, but is connected through interaction with other species at the same or adjacent trophic level. Using long-term phenological data observed since 1976 in Korea, whose temperature has risen more steeply than the average global temperature, this study conducted phenological analysis (differ-ences in the phenology of groups, differences in phenological shifts due to climate change, differ-ences in phenological sensitivity to climate by groups, and the change of phenological day differ-ences among interacting groups). The phenological shift of the producer group (plants) was found to be negative in all researched species, which means that it blooms quickly over the years. The regression slope of consumers (primary consumers and secondary consumers) was generally posi-tive which means that the phenological events of these species tended to be later during the study period. The inter-regional deviation of phenological events was not large for any plant except for plum tree and Black locust. In addition, regional variations in high trophic levels of secondary consumers tended to be greater than that of producers and primary consumers. Among the studied species, plum was the most sensitive to temperature, and when the temperature rose by 1 °C, the flowering time of plum decreased by 7.20 days. As a result of checking the day differences in the phenological events of the interacting species, the phenological events of species were reversed, and butterflies have appeared earlier than plum, Korean forsythia, and Korean rosebay since 1990. Using long-term data from Korea, this study investigated differences in phenological reactions among trophic groups. There is a possibility of a phenological mismatch between trophic groups in the future if global warming continues due to differences in sensitivity to climate and phenological shifts between trophic levels.


2020 ◽  
Vol 26 (24) ◽  
pp. 2817-2842
Author(s):  
Ewa Skała ◽  
Joanna Makowczyńska ◽  
Joanna Wieczfinska ◽  
Tomasz Kowalczyk ◽  
Przemysław Sitarek

Background: For a long time, the researchers have been looking for new efficient methods to enhance production and obtain valuable plant secondary metabolites, which would contribute to the protection of the natural environment through the preservation of various plant species, often rare and endangered. These possibilities offer plant in vitro cultures which can be performed under strictly-controlled conditions, regardless of the season or climate and environmental factors. Biotechnological methods are promising strategies for obtaining the valuable plant secondary metabolites with various classes of chemical compounds including caffeoylquinic acids (CQAs) and their derivatives. CQAs have been found in many plant species which are components in the daily diet and exhibit a wide spectrum of biological activities, including antioxidant, immunomodulatory, antihypertensive, analgesic, anti-inflammatory, hepato- and neuroprotective, anti-hyperglycemic, anticancer, antiviral and antimicrobial activities. They have also been found to offer protection against Alzheimer’s disease, and play a role in weight reduction and lipid metabolism control, as well as modulating the activity of glucose-6-phosphatase involved in glucose metabolism. Methods: This work presents the review of the recent advances in use in vitro cultures of various plant species for the alternative system to the production of CQAs and their derivatives. Production of the secondary metabolites in in vitro culture is usually performed with cell suspension or organ cultures, such as shoots and adventitious or transformed roots. To achieve high production of valuable secondary metabolites in in vitro cultures, the optimization of the culture condition is necessary with respect to both biomass accumulation and metabolite content. The optimization of the culture conditions can be achieved by choosing the type of medium, growth regulators or growth conditions, selection of high-productivity lines or culture period, supplementation of the culture medium with precursors or elicitor treatments. Cultivation for large-scale in bioreactors and genetic engineering: Agrobacterium rhizogenes transformation and expression improvement of transcriptional factor or genes involved in the secondary metabolite production pathway are also efficient strategies for enhancement of the valuable secondary metabolites. Results: Many studies have been reported to obtain highly productive plant in vitro cultures with respect to CQAs. Among these valuable secondary metabolites, the most abundant compound accumulated in in vitro cultures was 5-CQA (chlorogenic acid). Highly productive cultures with respect to this phenolic acid were Leonurus sibiricus AtPAP1 transgenic roots, Lonicera macranthoides and Eucomia ulmoides cell suspension cultures which accumulated above 20 mg g-1 DW 5-CQA. It is known that di- and triCQAs are less common in plants than monoCQAs, but it was also possible to obtain them by biotechnological methods. Conclusion: The results indicate that the various in vitro cultures of different plant species can be a profitable approach for the production of CQAs. In particular, an efficient production of these valuable compounds is possible by Lonicera macranthoides and Eucomia ulmoides cell suspension cultures, Leonurus sibiricus transformed roots and AtPAP1 transgenic roots, Echinacea angustifolia adventitious shoots, Rhaponticum carthamoides transformed plants, Lavandula viridis shoots, Sausera involucrata cell suspension and Cichorium intybus transformed roots.


2012 ◽  
Vol 13 (5) ◽  
pp. 632-650 ◽  
Author(s):  
David M. Pereira ◽  
Patricia Valentao ◽  
Georgina Correia-da-Silva ◽  
Natercia Teixeira ◽  
Paula B. Andrade

2020 ◽  
Vol 20 (12) ◽  
pp. 1093-1104 ◽  
Author(s):  
Muhammad Shoaib Ali Gill ◽  
Hammad Saleem ◽  
Nafees Ahemad

Natural Products (NP), specifically from medicinal plants or herbs, have been extensively utilized to analyze the fundamental mechanisms of ultimate natural sciences as well as therapeutics. Isolation of secondary metabolites from these sources and their respective biological properties, along with their lower toxicities and cost-effectiveness, make them a significant research focus for drug discovery. In recent times, there has been a considerable focus on isolating new chemical entities from natural flora to meet the immense demand for kinase modulators, and also to overcome major unmet medical challenges in relation to signal transduction pathways. The signal transduction systems are amongst the foremost pathways involved in the maintenance of life and protein kinases play an imperative part in these signaling pathways. It is important to find a kinase inhibitor, as it can be used not only to study cell biology but can also be used as a drug candidate for cancer and metabolic disorders. A number of plant extracts and their isolated secondary metabolites such as flavonoids, phenolics, terpenoids, and alkaloids have exhibited activities against various kinases. In the current review, we have presented a brief overview of some important classes of plant secondary metabolites as kinase modulators. Moreover, a number of phytocompounds with kinase inhibition potential, isolated from different plant species, are also discussed.


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