scholarly journals Fungal-Fungal Interactions in Leaf-Cutting Ant Agriculture

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Sunshine A. Van Bael ◽  
Catalina Estrada ◽  
William T. Wcislo
Keyword(s):  
Plant Traits ◽  
Secondary Compounds ◽  
Future Research ◽  
Ecological Interactions ◽  
Tropical Plants ◽  
Symbiotic Relationships ◽  
Complex Interactions ◽  
Symbiotic Fungi ◽  
Leaf Cutting ◽  
Fungal Interactions

Many organisms participate in symbiotic relationships with other organisms, yet studies of symbioses typically have focused on the reciprocal costs and benefits within a particular host-symbiont pair. Recent studies indicate that many ecological interactions involve alliances of symbionts acting together as mutualistic consortia against other consortia. Such interacting consortia are likely to be widespread in nature, even if the interactions often occur in a cryptic fashion. Little theory and empirical data exist concerning how these complex interactions shape ecological outcomes in nature. Here, we review recent work on fungal-fungal interactions between two consortia: (i) leaf-cutting ants and their symbiotic fungi (the latter grown as a food crop by the former) and (ii) tropical plants and their foliar endophytes (the cryptic symbiotic fungi within leaves of the former). Plant characteristics (e.g., secondary compounds or leaf physical properties of leaves) are involved in leaf-cutting ant preferences, and a synthesis of published information suggests that these plant traits could be modified by fungal presence. We discuss potential mechanisms for how fungal-fungal interactions proceed in the leaf-cutting ant agriculture and suggest themes for future research.

scholarly journals Species Diversity and Secondary Metabolites of Sarcophyton-Associated Marine Fungi

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3227
Author(s):  
Yuanwei Liu ◽  
Kishneth Palaniveloo ◽  
Siti Aisyah Alias ◽  
Jaya Seelan Sathiya Seelan
Keyword(s):  
Secondary Metabolites ◽  
Soft Coral ◽  
Marine Fungi ◽  
Indole Alkaloids ◽  
Structural Diversity ◽  
Future Research ◽  
Soft Corals ◽  
Diverse Range ◽  
Symbiotic Relationships ◽  
Bioactive Secondary Metabolites

Soft corals are widely distributed across the globe, especially in the Indo-Pacific region, with Sarcophyton being one of the most abundant genera. To date, there have been 50 species of identified Sarcophyton. These soft corals host a diverse range of marine fungi, which produce chemically diverse, bioactive secondary metabolites as part of their symbiotic nature with the soft coral hosts. The most prolific groups of compounds are terpenoids and indole alkaloids. Annually, there are more bio-active compounds being isolated and characterised. Thus, the importance of the metabolite compilation is very much important for future reference. This paper compiles the diversity of Sarcophyton species and metabolites produced by their associated marine fungi, as well as the bioactivity of these identified compounds. A total of 88 metabolites of structural diversity are highlighted, indicating the huge potential these symbiotic relationships hold for future research.

Invited Review: Possible Mechanisms Involved in the Immunoregulation of Chronic Inflammatory Periodontal Disease

1987 ◽  
Vol 66 (1) ◽  
pp. 2-9 ◽  
Author(s):  
G.J. Seymour
Keyword(s):  
Periodontal Disease ◽  
Animal Studies ◽  
Cellular Level ◽  
Future Research ◽  
Complex Interactions ◽  
Essentially Normal ◽  
Experimental Gingivitis ◽  
Immunological Mechanisms ◽  
Scant Attention ◽  
Macrophage Subpopulations

It is generally agreed that immunological mechanisms are involved in the pathogenesis of periodontal disease; however, regulation of these mechanisms has hitherto received scant attention. Regulatory net works exist at both a cellular and a molecular level. At the cellular level, the existence of helper (T4-positive) and suppressor (T8-positive) T lymphocytes, the expression of Class II major histocompatibility complex antigens, and the heterogeneity of macrophage subpopulations are central to an understanding of the regulatory mechanisms involved. It is only recently that studies of these separate components, in both humans and experimental animals, have begun to provide a basis for understanding the complex interactions occurring in periodontal disease. Studies using the human experimental gingivitis model have shown an immunoregulatory picture consistent with a controlled immunological reaction with an essentially normal T4:T8 ratio of 2.0. In con trast, studies utilizing cells extracted from adult periodontitis lesions have shown a reduced T4:T8 ratio (approximately 1.0) and an inability to respond in, or to stimulate, an autologous mixed lymphocyte reaction. Animal studies using athymic nude rats have supported the concept of a central role for T-cell control in periodontal disease and the possibility of an imbalance in this control with disease progression. These results are reviewed and areas of future research explored.

scholarly journals Plant Secondary Metabolism: Diversity, Function and its Evolution

2008 ◽  
Vol 3 (8) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Michael Wink
Keyword(s):  
Secondary Metabolites ◽  
Main Function ◽  
Symbiotic Relationships ◽  
Pathway Gene ◽  
Interesting Pattern ◽  
Differential Gene Regulation ◽  
Symbiotic Fungi ◽  
Differential Gene ◽  
Taxonomic Groups ◽  
Occurrence Patterns

A typical character of plants is the production and storage of usually complex mixtures of secondary metabolites (SM). The main function of secondary metabolites is defense against herbivores and microbes; some SM are signal compounds to attract pollinating and seed dispersing animals or play a role in the symbiotic relationships with plants and microbes. The distribution of SM in the plant kingdom shows an interesting pattern. A specific SM is often confined to a particular systematic unit, but isolated occurrences can occur in widely unrelated taxonomic groups. This review tries to explain the patchy occurrence of SM in plants. It could be due to convergent evolution, but evidence is provided that the genes that encode the biosynthesis of SM appear to have a much wider distribution than the actual secondary metabolite. It seems to be rather a matter of differential gene regulation whether a pathway is active and expressed in a given taxonomic unit or not. It is speculated that the genes of some pathways derived from an early horizontal gene transfer from bacteria, which later became mitochondria and chloroplasts. These genes/pathways should be present in most if not all land plants. About 80% of plants live in close symbiotic relationships with symbiotic fungi (ectomycorrhiza, endophytes). Recent evidence is presented that these fungi can either directly produce SM, which were formerly considered as plant SM or that these fungi have transferred the corresponding pathway gene to the host plant. The fungal contribution could also explain part of the patchy occurrence patterns of several secondary metabolites.

scholarly journals Recurrent Cholera Outbreaks in Sub-Saharan Africa: Moving beyond Epidemiology to Understand the Environmental Reservoirs and Drivers

Challenges ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
Willis Gwenzi ◽  
Edmond Sanganyado
Keyword(s):  
Epidemiological Studies ◽  
Sub Saharan Africa ◽  
Environmental Drivers ◽  
Future Research ◽  
Research Directions ◽  
Complex Interactions ◽  
Future Research Directions ◽  
Sub Saharan ◽  
And Control ◽  
Water Borne

Recurrent cholera outbreaks in sub-Saharan Africa (SSA) attracted a lot of research interest, raising questions about the effectiveness of current prevention and control methods. However, research on cholera and other water-borne diseases in Africa is dominated by epidemiological studies, while investigations on the environmental drivers and reservoirs of cholera remain scarce. The current discourse relating cholera to the environment in SSA is often limited to the rudimentary statement that, “cholera is caused by the consumption of contaminated water and food”. Yet, beyond this simplistic view, literature elsewhere shows that cholera outbreaks are controlled by its complex interactions with environmental drivers and reservoirs. This brings to question whether cholera can be eradicated in SSA without understanding these complex interactions. The current review seeks to (1) highlight the nature and dynamics of recent cholera outbreaks in SSA, (2) discuss the importance of environmental reservoirs of Vibrio cholerae, and anthropogenic and hydroclimatic drivers in controlling the dynamics of cholera outbreaks, and (3) highlight key knowledge gaps and future research directions, and the need to harness emerging research tools such as modeling, machine learning, data mining, and genomics techniques to better understand the cholera dynamics. By bringing to fore these often-overlooked issues in cholera research, we seek to stimulate discussion, and promote a shift toward cross-disciplinary research on cholera and other water-borne diseases in SSA and beyond.

scholarly journals Phylogenetic overdispersion of plant species in southern Brazilian savannas

2009 ◽  
Vol 69 (3) ◽  
pp. 843-849 ◽  
Author(s):  
IA. Silva ◽  
MA. Batalha
Keyword(s):  
Phylogenetic Relationships ◽  
Plant Traits ◽  
Environmental Filtering ◽  
Southeastern Brazil ◽  
Ecological Communities ◽  
Ecological Interactions ◽  
Ecological Processes ◽  
Phylogenetic Structure ◽  
History Of ◽  
Phylogenetic Overdispersion

Ecological communities are the result of not only present ecological processes, such as competition among species and environmental filtering, but also past and continuing evolutionary processes. Based on these assumptions, we may infer mechanisms of contemporary coexistence from the phylogenetic relationships of the species in a community. We studied the phylogenetic structure of plant communities in four cerrado sites, in southeastern Brazil. We calculated two raw phylogenetic distances among the species sampled. We estimated the phylogenetic structure by comparing the observed phylogenetic distances to the distribution of phylogenetic distances in null communities. We obtained null communities by randomizing the phylogenetic relationships of the regional pool of species. We found a phylogenetic overdispersion of the cerrado species. Phylogenetic overdispersion has several explanations, depending on the phylogenetic history of traits and contemporary ecological interactions. However, based on coexistence models between grasses and trees, density-dependent ecological forces, and the evolutionary history of the cerrado flora, we argue that the phylogenetic overdispersion of cerrado species is predominantly due to competitive interactions, herbivores and pathogen attacks, and ecological speciation. Future studies will need to include information on the phylogenetic history of plant traits.

scholarly journals A Review of the Ephedra genus: Distribution, Ecology, Ethnobotany, Phytochemistry and Pharmacological Properties

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3283
Author(s):  
Daphne E. González-Juárez ◽  
Abraham Escobedo-Moratilla ◽  
Joel Flores ◽  
Sergio Hidalgo-Figueroa ◽  
Natalia Martínez-Tagüeña ◽  
...  
Keyword(s):  
Chemical Constituents ◽  
Nasal Congestion ◽  
Building Blocks ◽  
Relevant Information ◽  
Chemical Diversity ◽  
Future Research ◽  
Pharmacological Properties ◽  
Ecological Interactions ◽  
Phytochemical Study ◽  
Promising Area

Ephedra is one of the largest genera of the Ephedraceae family, which is distributed in arid and semiarid regions of the world. In the traditional medicine from several countries some species from the genus are commonly used to treat asthma, cold, flu, chills, fever, headache, nasal congestion, and cough. The chemical constituents of Ephedra species have been of research interest for decades due to their contents of ephedrine-type alkaloids and its pharmacological properties. Other chemical constituents such as phenolic and amino acid derivatives also have resulted attractive and have provided evidence-based supporting of the ethnomedical uses of the Ephedra species. In recent years, research has been expanded to explore the endophytic fungal diversity associated to Ephedra species, as well as, the chemical constituents derived from these fungi and their pharmacological bioprospecting. Two additional aspects that illustrate the chemical diversity of Ephedra genus are the chemotaxonomy approaches and the use of ephedrine-type alkaloids as building blocks in organic synthesis. American Ephedra species, especially those that exist in Mexico, are considered to lack ephedrine type alkaloids. In this sense, the phytochemical study of Mexican Ephedra species is a promising area of research to corroborate their ephedrine-type alkaloids content and, in turn, discover new chemical compounds with potential biological activity. Therefore, the present review represents a key compilation of all the relevant information for the Ephedra genus, in particular the American species, the species distribution, their ecological interactions, its ethnobotany, its phytochemistry and their pharmacological activities and toxicities, in order to promote clear directions for future research.

Ecological Interactions and Macroevolution: A New Field with Old Roots

2020 ◽  
Vol 51 (1) ◽  
pp. 215-243 ◽  
Author(s):  
David H. Hembry ◽  
Marjorie G. Weber
Keyword(s):  
Species Interactions ◽  
Interspecific Interactions ◽  
Biotic Interactions ◽  
Evolutionary Change ◽  
Future Research ◽  
Ecological Interactions ◽  
Open Questions ◽  
Work Done ◽  
Lineage Diversification

Linking interspecific interactions (e.g., mutualism, competition, predation, parasitism) to macroevolution (evolutionary change on deep timescales) is a key goal in biology. The role of species interactions in shaping macroevolutionary trajectories has been studied for centuries and remains a cutting-edge topic of current research. However, despite its deep historical roots, classic and current approaches to this topic are highly diverse. Here, we combine historical and contemporary perspectives on the study of ecological interactions in macroevolution, synthesizing ideas across eras to build a zoomed-out picture of the big questions at the nexus of ecology and macroevolution. We discuss the trajectory of this important and challenging field, dividing research into work done before the 1970s, research between 1970 and 2005, and work done since 2005. We argue that in response to long-standing questions in paleobiology, evidence accumulated to date has demonstrated that biotic interactions (including mutualism) can influence lineage diversification and trait evolution over macroevolutionary timescales, and we outline major open questions for future research in the field.

A review of the distribution and host plant associations of the platypodine ambrosia beetles (Coleoptera: Curculionidae: Platypodinae) of Australia, with an electronic species identification key

Zootaxa ◽  
2020 ◽  
Vol 4894 (1) ◽  
pp. 69-80
Author(s):  
JAMES R. M. BICKERSTAFF ◽  
SHANNON S. SMITH ◽  
DEBORAH S. KENT ◽  
ROGER A. BEAVER ◽  
AINSLEY E. SEAGO ◽  
...  
Keyword(s):  
Woody Plants ◽  
Morphological Characteristics ◽  
Identification Key ◽  
Host Tree ◽  
Future Research ◽  
Ecological Interactions ◽  
Journal Articles ◽  
Ambrosia Beetles ◽  
Plant Associations ◽  
Online Databases

Ambrosia beetles (Platypodinae and some Scolytinae) are ecologically and economically important weevils (Coleoptera: Curculionidae) that develop within the sapwood and heartwood of woody plants, and their larval and adult stages are dependent on fungal symbionts. Platypodinae mostly occur in tropical and subtropical biomes, with a few species occurring in temperate regions. Australia has 44 recorded platypodine species including 13 species which may only have been intercepted at or near ports of entries and are without established populations in Australia. The host tree associations and biogeography of Australian Platypodinae are largely undocumented, and no comprehensive identification key exists. Here, we review species records, host tree associations, biogeographic distributions, and morphological characteristics of Australian Platypodinae. For this, we examined collection specimens, monographs, catalogues, taxonomic inventories, journal articles and online databases, and developed an electronic LUCID identification key for 36 species recorded in Australia. This review and identification key will be a valuable resource for forestry managers and biosecurity officers and will support diagnostics and future research of these beetles, their biology, and ecological interactions. 

scholarly journals Evolving symbioses between insects and fungi that kill trees in Canada: new threats associated with invasive organisms

2016 ◽  
Vol 148 (S1) ◽  
pp. S160-S169 ◽  
Author(s):  
Tod D. Ramsfield
Keyword(s):  
Tree Mortality ◽  
Forest Ecosystems ◽  
Larval Feeding ◽  
Invasive Insects ◽  
Symbiotic Relationships ◽  
Direct Damage ◽  
Invasive Organisms ◽  
Forested Landscapes ◽  
Evolutionary Trajectories ◽  
Symbiotic Fungi

AbstractSymbiotic relationships between insects and fungi are known to cause tree mortality either through direct damage by larval feeding that can be facilitated by symbiotic fungi, or through insects vectoring pathogens directly to healthy trees. Within their native ranges, the impacts of many insect-fungus symbioses are restricted to weakened and declining trees; however, within the last century tree mortality caused by globally invasive insect–fungus associations has had a devastating impact on trees in both urban and natural forest ecosystems. Unfortunately, Canadian forests have been seriously affected by invasive organisms and an emerging threat is the expansion of a native bark beetle into the boreal forest of Alberta. This paper reviews the symbiotic relationships between selected invasive insects and pathogens that cause tree mortality within the urban and forested landscapes of Canada; it uses these case studies to illustrate potentially damaging new evolutionary trajectories.

Sign in / Sign up

Export Citation Format

Share Document