Chemistry of marine symbiotic interactions in ascidians and mollusks

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
EW Schmidt
Keyword(s):  
Symbiotic Interactions

scholarly journals Tripartite parasitic and symbiotic interactions as a possible mechanism of horizontal gene transfer

2021 ◽  
Author(s):  
Chaoyang Zhao ◽  
Shaoming Miao ◽  
Yanfang Yin ◽  
Yanjuan Zhu ◽  
Paul Nabity ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Symbiotic Interactions

Comparative ultrastructural analysis of mycorrhizal associations

1983 ◽  
Vol 61 (3) ◽  
pp. 917-943 ◽  
Author(s):  
Silvano Scannerini ◽  
Paola Bonfante-Fasolo
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Ultrastructural Analysis ◽  
Nutrient Transfer ◽  
Cytological Feature ◽  
Symbiotic Interactions ◽  
Mycorrhizal Associations ◽  
Host Pathogen ◽  
Bacterial Associations ◽  
Functional Mechanisms

Electron microscopy is a powerful tool in understanding functional mechanisms in symbiosis (i.e., recognition and transfer of nutrients between partners), but mycorrhizal associations are not yet so well known as host–pathogen and host – mutualistic bacterial associations. However, the study of mycorrhizal ultrastructure has provided some interesting information. In fact unknown symbionts can be recognized with electron microscopy and mycorrhizae can be classified according to a sequence linking intercellular and intracellular interactions between host and fungus. General conclusions can be drawn from this ultrastructural sequence. (i) The most significant cytological feature in mycorrhizae is the presence of an interface through which partners communicate along a vast surface area. This is the key area for symbiotic interactions (both recognition and nutrient transfer) and can vary a great deal mostly in intracellular interactions. (ii) The ultracytochemical aspects of those interfaces, mostly as regards the components of the interfacial matrix, appear quite different from those of host–pathogen associations and suggest a compatibility mechanism. (iii) As regards the transfer of nutrients, even though it has been claimed that transfer of nutrient in all intracellular interactions is achieved by a digestion mechanism of the fungus by the host, available ultrastructural data are not consistent with this hypothesis.

scholarly journals Dissecting host-associated communities with DNA barcodes

2016 ◽  
Vol 371 (1702) ◽  
pp. 20150328 ◽  
Author(s):  
Christopher C. M. Baker ◽  
Leonora S. Bittleston ◽  
Jon G. Sanders ◽  
Naomi E. Pierce
Keyword(s):  
Species Interactions ◽  
Morphological Characters ◽  
South American ◽  
Dna Barcodes ◽  
Substantial Variation ◽  
East African ◽  
Pitcher Plant ◽  
Genome Data ◽  
Symbiotic Interactions ◽  
Database Connectivity

DNA barcoding and metabarcoding methods have been invaluable in the study of interactions between host organisms and their symbiotic communities. Barcodes can help identify individual symbionts that are difficult to distinguish using morphological characters, and provide a way to classify undescribed species. Entire symbiont communities can be characterized rapidly using barcoding and especially metabarcoding methods, which is often crucial for isolating ecological signal from the substantial variation among individual hosts. Furthermore, barcodes allow the evolutionary histories of symbionts and their hosts to be assessed simultaneously and in reference to one another. Here, we describe three projects illustrating the utility of barcodes for studying symbiotic interactions: first, we consider communities of arthropods found in the ant-occupied domatia of the East African ant-plant Vachellia ( Acacia ) drepanolobium ; second, we examine communities of arthropod and protozoan inquilines in three species of Nepenthes pitcher plant in South East Asia; third, we investigate communities of gut bacteria of South American ants in the genus Cephalotes . Advances in sequencing and computation, and greater database connectivity, will continue to expand the utility of barcoding methods for the study of species interactions, especially if barcoding can be approached flexibly by making use of alternative genetic loci, metagenomes and whole-genome data. This article is part of the themed issue ‘From DNA barcodes to biomes’.

Deciphering the Chitin Code in Plant Symbiosis, Defense, and Microbial Networks

2021 ◽  
Vol 75 (1) ◽  
pp. 583-607
Author(s):  
Devanshi Khokhani ◽  
Cristobal Carrera Carriel ◽  
Shivangi Vayla ◽  
Thomas B. Irving ◽  
Christina Stonoha-Arther ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Growth And Development ◽  
Fungal Growth ◽  
Mycorrhizal Symbiosis ◽  
Signal Molecules ◽  
Symbiotic Relationship ◽  
Beneficial Microbes ◽  
Symbiotic Interactions ◽  
Microbe Interactions ◽  
Structural Polymer

Chitin is a structural polymer in many eukaryotes. Many organisms can degrade chitin to defend against chitinous pathogens or use chitin oligomers as food. Beneficial microorganisms like nitrogen-fixing symbiotic rhizobia and mycorrhizal fungi produce chitin-based signal molecules called lipo-chitooligosaccharides (LCOs) and short chitin oligomers to initiate a symbiotic relationship with their compatible hosts and exchange nutrients. A recent study revealed that a broad range of fungi produce LCOs and chitooligosaccharides (COs), suggesting that these signaling molecules are not limited to beneficial microbes. The fungal LCOs also affect fungal growth and development, indicating that the roles of LCOs beyond symbiosis and LCO production may predate mycorrhizal symbiosis. This review describes the diverse structures of chitin; their perception by eukaryotes and prokaryotes; and their roles in symbiotic interactions, defense, and microbe-microbe interactions. We also discuss potential strategies of fungi to synthesize LCOs and their roles in fungi with different lifestyles.

scholarly journals Important Late-Stage Symbiotic Role of theSinorhizobium melilotiExopolysaccharide Succinoglycan

2018 ◽  
Vol 200 (13) ◽  
pp. e00665-17 ◽  
Author(s):  
Markus F. F. Arnold ◽  
Jon Penterman ◽  
Mohammed Shabab ◽  
Esther J. Chen ◽  
Graham C. Walker
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Late Stage ◽  
Sinorhizobium Meliloti ◽  
Antimicrobial Action ◽  
Protective Function ◽  
Content Type ◽  
Early Stages ◽  
Symbiotic Interactions ◽  
Legume Symbiosis

ABSTRACTSinorhizobium melilotienters into beneficial symbiotic interactions withMedicagospecies of legumes. Bacterial exopolysaccharides play critical signaling roles in infection thread initiation and growth during the early stages of root nodule formation. After endocytosis ofS. melilotiby plant cells in the developing nodule, plant-derived nodule-specific cysteine-rich (NCR) peptides mediate terminal differentiation of the bacteria into nitrogen-fixing bacteroids. Previous transcriptional studies showed that the intensively studied cationic peptide NCR247 induces expression of theexogenes that encode the proteins required for succinoglycan biosynthesis. In addition, genetic studies have shown that someexomutants exhibit increased sensitivity to the antimicrobial action of NCR247. Therefore, we investigated whether the symbiotically activeS. melilotiexopolysaccharide succinoglycan can protectS. melilotiagainst the antimicrobial activity of NCR247. We discovered that high-molecular-weight forms of succinoglycan have the ability to protectS. melilotifrom the antimicrobial action of the NCR247 peptide but low-molecular-weight forms of wild-type succinoglycan do not. The protective function of high-molecular-weight succinoglycan occurs via direct molecular interactions between anionic succinoglycan and the cationic NCR247 peptide, but this interaction is not chiral. Taken together, our observations suggest thatS. melilotiexopolysaccharides not only may be critical during early stages of nodule invasion but also are upregulated at a late stage of symbiosis to protect bacteria against the bactericidal action of cationic NCR peptides. Our findings represent an important step forward in fully understanding the complete set of exopolysaccharide functions during legume symbiosis.IMPORTANCESymbiotic interactions between rhizobia and legumes are economically important for global food production. The legume symbiosis also is a major part of the global nitrogen cycle and is an ideal model system to study host-microbe interactions. Signaling between legumes and rhizobia is essential to establish symbiosis, and understanding these signals is a major goal in the field. Exopolysaccharides are important in the symbiotic context because they are essential signaling molecules during early-stage symbiosis. In this study, we provide evidence suggesting that theSinorhizobium melilotiexopolysaccharide succinoglycan also protects the bacteria against the antimicrobial action of essential late-stage symbiosis plant peptides.

Microbial Diversity and Symbiotic Interactions with Macroalgae

2016 ◽  
pp. 493-546
Author(s):  
Suhelen EGAN ◽  
Vipra KUMAR ◽  
Jadranka NAPPI ◽  
Melissa GARDINER
Keyword(s):  
Microbial Diversity ◽  
Symbiotic Interactions

scholarly journals Complete Genome Sequence of theBacillus pumilusPhage Leo2

2018 ◽  
Vol 6 (7) ◽  
Author(s):  
Sondos Badran ◽  
Nathanael Morales ◽  
Phillip Schick ◽  
Brandon Jacoby ◽  
William Villella ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Bacillus Pumilus ◽  
Open Reading Frames ◽  
Gram Positive ◽  
Coding Regions ◽  
Symbiotic Interactions ◽  
Associated Functions ◽  
Reading Frames

ABSTRACTBacillusspp. are ubiquitous Gram-positive microbes with many ecological and symbiotic interactions and can be pathogens. Phage Leo2 was found to infect aBacillus pumilusstrain isolated from soil. The sequence of phage Leo2 revealed 74 genes; 31% of the genes have associated functions, and 67% of coding regions are unidentified open reading frames.

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