During the last few years, the analysis of microbial diversity in various habitats greatly increased our knowledge on the kingdom Archaea. At the same time, we became aware of the multiple ways in which Archaea may interact with each other and with organisms of other kingdoms. The large group of euryarchaeal methanogens and their methane oxidizing relatives, in particular, take part in essentia...

Symbiotic associations accompanied by gene exchange between the symbionts form the phylogenetic origin of eukaryotic cells and, therefore, had significant impact on species diversity and evolutionary novelty. Among the phylogenetically oldest metazoan animals known to form symbiotic relationships are the Cnidaria. In the Cnidarian Hydra viridis, symbiotic algae of the genus Chlorella are locate...

Root nodule structural organisation of nine pea Fix(-) mutants representing seven symbiotic loci has been studied. This set of mutants has revealed lesions at four developmental stages in the pea-Rhizobium symbiosis. (i) Mutant RisFixA is affected in infection thread differentiation in nodule tissue, infection droplet formation, bacteroid differentiation and nodule persistence. (ii) Allelic mut...

This chapter presents SMuGA, an integration of symbiogenesis with the Multiset Genetic Algorithm (MuGA). The symbiogenetic approach used here is based on the host-parasite model with the novelty of varying the length of parasites along the evolutionary process. Additionally, it models collaborations between multiple parasites and a single host. To improve efficiency, we introduced proxy evaluat...

Certain cyanobacteria can form symbiotic associations with plants, where the symbiont supplies the plant partner with nitrogen and in return obtains sugars. We recently showed that in the symbiotic cyanobacterium Nostoc punctiforme, a glucose specific permease, GlcP, is necessary for the symbiosis to be formed. Results presented here from growth yield measurements of mutant strains with inactiv...

Microorganisms could play an important role in adaptation strategies and increase of tolerance to abiotic stresses in agricultural plants. Plant-growth-promoting rhizobacteria (PGPR) mitigate most effectively the impact of abiotic stresses (drought, low temperature, salinity, metal toxicity, and high temperatures) on plants through the production of exopolysaccharates and biofilm formation. PGP...

We report the first spatially resolved radio continuum measurements of the Mira AB symbiotic binary system, based on observations obtained with the Very Large Array (VLA). This is the first time that a symbiotic binary has been resolved unambiguously at centimeter wavelengths. We describe the results of VLA monitoring of both stars over a ten month period, together with constraints on their ind...

The purpose of this theme is to develop an actual system based on the outcome of the 21st Century COE (Center of Excellence) Project. It is important for the program to spread its potentialities and symbiotic information systems. Therefore, we proposed an object selection system as an instance of an actual symbiotic information system. The system is based on a compound image capturing system an...

The inhibitory effect of nitrate on nitrogenase activity in root nodules of legume plants has been known for a long time. The major factor inducing changes in nitrogenase activity is the concentration of free oxygen inside nodules. Oxygen availability in the infected zone of nodule is limited, among others, by the gas diffusion resistance in nodule cortex. The presence of nitrate may cause chan...

A single cell of the green paramecia (Paramecium bursaria) harbors several hundreds of endo-symbiotic Chlorella-like algae in its cytoplasm. Removal of algae from the host organism and re-association of ex-symbiotic host paramecia with ex-symbiotic algae can be experimentally demonstrated in the laboratory. However, the mechanism precisely governing the alga-protozoan association is not fully u...