Symbiont-mediated insecticide resistance Kikuchi, Yoshitomo; Hayatsu, Masahito; Hosokawa, Takahiro ...
Proceedings of the National Academy of Sciences,
05/2012, Volume:
109, Issue:
22
Journal Article
Peer reviewed
Open access
Development of insecticide resistance has been a serious concern worldwide, whose mechanisms have been attributed to evolutionary changes in pest insect genomes such as alteration of drug target ...sites, up-regulation of degrading enzymes, and enhancement of drug excretion. Here, we report a previously unknown mechanism of insecticide resistance: Infection with an insecticide-degrading bacterial symbiont immediately establishes insecticide resistance in pest insects. The bean bug Riptortus pedestris and allied stinkbugs harbor mutualistic gut symbiotic bacteria of the genus Burkholderia, which are acquired by nymphal insects from environmental soil every generation. In agricultural fields, fenitrothion-degrading Burkolderia strains are present at very low densities. We demonstrated that the fenitrothion-degrading Burkholderia strains establish a specific and beneficial symbiosis with the stinkbugs and confer a resistance of the host insects against fenitrothion. Experimental applications of fenitrothion to field soils drastically enriched fenitrothion-degrading bacteria from undetectable levels to >80% of total culturable bacterial counts in the field soils, and >90% of stinkbugs reared with the enriched soil established symbiosis with fenitrothion-degrading BURKHOLDERIA: In a Japanese island where fenitrothion has been constantly applied to sugarcane fields, we identified a stinkbug population wherein the insects live on sugarcane and ≈8% of them host fenitrothion-degrading BURKHOLDERIA: Our finding suggests the possibility that the symbiont-mediated insecticide resistance may develop even in the absence of pest insects, quickly establish within a single insect generation, and potentially move around horizontally between different pest insects and other organisms.
In legumes, Ca²⁺/calmodulin-dependent protein kinase (CCaMK) is a component of the common symbiosis genes that are required for both root nodule (RN) and arbuscular mycorrhiza (AM) symbioses and is ...thought to be a decoder of Ca²⁺ spiking, one of the earliest cellular responses to microbial signals. A gain-of-function mutation of CCaMK has been shown to induce spontaneous nodulation without rhizobia, but the significance of CCaMK activation in bacterial and/or fungal infection processes is not fully understood. Here we show that a gain-of-function CCaMKT²⁶⁵D suppresses loss-of-function mutations of common symbiosis genes required for the generation of Ca²⁺ spiking, not only for nodule organogenesis but also for successful infection of rhizobia and AM fungi, demonstrating that the common symbiosis genes upstream of Ca²⁺ spiking are required solely to activate CCaMK. In RN symbiosis, however, CCaMKT²⁶⁵D induced nodule organogenesis, but not rhizobial infection, on Nod factor receptor (NFRs) mutants. We propose a model of symbiotic signaling in host legume plants, in which CCaMK plays a key role in the coordinated induction of infection thread formation and nodule organogenesis.
•Options to reduce industry GHG emissions.•Review and analysis of energy symbiosis schemes including renewable energy sources.•Energy strategy within eco-industrial parks to promote the use of ...renewable energy sources.•Urban-industrial energy symbiosis including renewable energy sources.
Replacing fossil fuels with renewable energy sources is considered as an effective means to reduce carbon emissions at the industrial level and it is often supported by local authorities. However, individual firms still encounter technical and financial barriers that hinder the installation of renewables. The eco-industrial park approach aims to create synergies among firms thereby enabling them to share and efficiently use natural and economic resources. It also provides a suitable model to encourage the use of renewable energy sources in the industry sector. Synergies among eco-industrial parks and the adjacent urban areas can lead to the development of optimized energy production plants, so that the excess energy is available to cover some of the energy demands of nearby towns. This study thus provides an overview of the scientific literature on energy synergies within eco-industrial parks, which facilitate the uptake of renewable energy sources at the industrial level, potentially creating urban-industrial energy symbiosis. The literature analysis was conducted by arranging the energy-related content into thematic categories, aimed at exploring energy symbiosis options within eco-industrial parks. It focuses on the urban-industrial energy symbiosis solutions, in terms of design and optimization models, technologies used and organizational strategies. The study highlights four main pathways to implement energy synergies, and demonstrates viable solutions to improve renewable energy sources uptake at the industrial level. A number of research gaps are also identified, revealing that the energy symbiosis networks between industrial and urban areas integrating renewable energy systems, are under-investigated.
 Thirty-nine species of symbiotic copepods, comprising 24 species of poecilostome Cyclopoida and 15 species of Siphonostomatoida, are reported from Korean waters, which were collected using ...underwater light traps at 33 collection sites around the South Korean coast. Ten new species are described: Hemicyclops rapax sp. nov. in the family Clausidiidae; Pontoclausia cochleata sp. nov. and P. pristina sp. nov. in the family Clausiidae; Heteranthessius unisetatus sp. nov. in the family Lichomolgidae; Pusanomyicola sensitivus gen. nov., sp. nov. in the family Myicolidae; Polyankylis bogilensis sp. nov. in the family Polyankyliidae; Pseudanthessius linguifer sp. nov. in the Pseudanthessiidae; Eupolymniphilus foliatus sp. nov. in the family Sabelliphilidae; and Acontiophorus estivalis sp. nov. and Thermocheres pacificus sp. nov . in the family Asterocheridae. Supplementary descriptions or notes for other species are provided as appropriate. Keywords: Copepoda , Crustacea , new genus, new species, taxonomy
For more than 30 years, the association between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium Vibrio fischeri has been studied as a model system for understanding ...the colonization of animal epithelia by symbiotic bacteria. The squid-vibrio light-organ system provides the exquisite resolution only possible with the study of a binary partnership. The impact of this relationship on the partners' biology has been broadly characterized, including their ecology and evolutionary biology as well as the underlying molecular mechanisms of symbiotic dynamics. Much has been learned about the factors that foster initial light-organ colonization, and more recently about the maturation and long-term maintenance of the association. This Review synthesizes the results of recent research on the light-organ association and also describes the development of new horizons for E. scolopes as a model organism that promises to inform biology and biomedicine about the basic nature of host-microorganism interactions.
Plants engage in mutually beneficial relationships with microbes, such as arbuscular mycorrhizal fungi or nitrogen-fixing rhizobia, for optimized nutrient acquisition. In return, the microbial ...symbionts receive photosynthetic carbon from the plant. Both symbioses are regulated by the plant nutrient status, indicating the existence of signaling pathways that allow the host to fine-tune its interactions with the beneficial microbes depending on its nutrient requirements. Peptide hormones coordinate a plethora of developmental and physiological processes and, recently, various peptide families have gained special attention as systemic and local regulators of plant–microbe interactions and nutrient homeostasis. In this review, we identify five ‘rules’ or guiding principles that govern peptide function during symbiotic plant–microbe interactions, and highlight possible points of integration with nutrient acquisition pathways.
Plant interactions with arbuscular mycorrhizal fungi, beneficial soil bacteria, and nutrient homeostasis are optimized by an interconnected network of peptide signals.Symbiosis-regulating signaling peptides are members of large protein families, often with a variety of functions in plant physiology and development.The mechanism of peptide-signaling specificity in the context of plant–microbe interactions, nutrient homeostasis, and cross-kingdom peptide mimicry involves antagonism and coordination between individual peptide signals.Although many of the symbiosis-associated peptide signaling pathways converge at common downstream signaling hubs and intersect with phytohormone signaling, the signaling outcomes are, at least partially, unique.
Arbuscular mycorrhizal (AM) symbioses are mutualistic associations between soil fungi and most vascular plants. The symbiosis significantly affects the host physiology in terms of nutrition and ...stress resistance. Despite the lack of host range specificity of the interaction, functional diversity between AM fungal species exists. The interaction is finely regulated according to plant and fungal characters, and plant hormones are believed to orchestrate the modifications in the host plant. Using tomato as a model, an integrative analysis of the host response to different mycorrhizal fungi was performed combining multiple hormone determination and transcriptional profiling. Analysis of ethylene-, abscisic acid-, salicylic acid-, and jasmonate-related compounds evidenced common and divergent responses of tomato roots to Glomus mosseae and Glomus intraradices, two fungi differing in their colonization abilities and impact on the host. Both hormonal and transcriptional analyses revealed, among others, regulation of the oxylipin pathway during the AM symbiosis and point to a key regulatory role for jasmonates. In addition, the results suggest that specific responses to particular fungi underlie the differential impact of individual AM fungi on plant physiology, and particularly on its ability to cope with biotic stresses.
Host specificity of the gut microbiome Mallott, Elizabeth K; Amato, Katherine R
Nature reviews. Microbiology,
10/2021, Volume:
19, Issue:
10
Journal Article
Peer reviewed
Developing general principles of host-microorganism interactions necessitates a robust understanding of the eco-evolutionary processes that structure microbiota. Phylosymbiosis, or patterns of ...microbiome composition that can be predicted by host phylogeny, is a unique framework for interrogating these processes. Identifying the contexts in which phylosymbiosis does and does not occur facilitates an evaluation of the relative importance of different ecological processes in shaping the microbial community. In this Review, we summarize the prevalence of phylosymbiosis across the animal kingdom on the basis of the current literature and explore the microbial community assembly processes and related host traits that contribute to phylosymbiosis. We find that phylosymbiosis is less prevalent in taxonomically richer microbiomes and hypothesize that this pattern is a result of increased stochasticity in the assembly of complex microbial communities. We also note that despite hosting rich microbiomes, mammals commonly exhibit phylosymbiosis. We hypothesize that this pattern is a result of a unique combination of mammalian traits, including viviparous birth, lactation and the co-evolution of haemochorial placentas and the eutherian immune system, which compound to ensure deterministic microbial community assembly. Examining both the individual and the combined importance of these traits in driving phylosymbiosis provides a new framework for research in this area moving forward.
The arbuscular mycorrhizal (AM) symbiosis is a beneficial association established between land plants and the members of a subphylum of fungi, the Glomeromycotina. How the two symbiotic partners ...regulate their association is still enigmatic. Secreted fungal peptides are candidates for regulating this interaction.
We searched for fungal peptides with similarities with known plant signalling peptides.
We identified CLAVATA (CLV)/EMBRYO SURROUNDING REGION (ESR)-RELATED PROTEIN (CLE) genes in phylogenetically distant AM fungi: four Rhizophagus species and one Gigaspora species. These CLE genes encode a signal peptide for secretion and the conserved CLE C-terminal motif. They seem to be absent in the other fungal clades. Rhizophagus irregularis and Gigaspora rosea CLE genes (RiCLE1 and GrCLE1) are transcriptionally induced in symbiotic vs asymbiotic conditions. Exogenous application of synthetic RiCLE1 peptide on Medicago truncatula affects root architecture, by slowing the apical growth of primary roots and stimulating the formation of lateral roots. In addition, pretreatment of seedlings with RiCLE1 peptide stimulates mycorrhization.
Our findings demonstrate for the first time that in addition to plants and nematodes,AMfungi also possess CLE genes. These results pave the way for deciphering new mechanisms by which AM fungi modulate plant cellular responses during the establishment of AM symbiosis.
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