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The legume–rhizobia symbiosis is a unique natural phenomenon, which supplies the plant with the necessary mineral nitrogen via fixation of atmospheric dinitrogen. This interaction involves two partners: the legume plant and root nodule bacteria (rhizobia). In the wild, members of the Fabaceae family enter into symbiosis with a polymorphic group of rhizobia specific to them; the mechanism and reasons for the formation of heterogeneity of rhizobia are currently the subject of active research. In the present work, a Rhizobium leguminosarum strain strictly specific to Phaseolus vulgaris L. was used to show that within 30 days upon its introduction into soil, genetic rearrangements occurred in the cells, as was revealed by changes in the pattern of its genetic profile. It was also found that recombination activity of the cells was also affected by the root exudates produced during seed germination, which may indicate involvement of the plant in the formation of polymorphism of its microsymbionts. These findings suggest interpretation of this process not as a spontaneous event, but rather as an event controlled by the plant. [ABSTRACT FROM AUTHOR]

The legume-Rhizobium symbiosis is a unique natural phenomenon responsible for providing a legume plant with mineral nitrogen fixed from the atmosphere. In the temperate climatic zone, due to seasonal cycles, plants have to form new interactions with rhizobia at the beginning of each round of vegetation with the formation of specialized structures on the roots, called root nodules, where molecular nitrogen is actually fixed. Nitrogen requirements of the host vary depending on the period of plant growth and development, which may affect its trophic relationships with the microsymbionts. In the present work, using the perennial leguminous plant Lotus corniculatus L. as an example, we assessed the influence of the macrosymbiont vegetation stage on the composition of its root nodule bacteria and carried out the characterization of these microbial communities. The highest microbial genetic diversity was found in the communities developing at the beginning of L. corniculatus vegetation. At the medium stage of plant development, the diversity decreased, while by the end of vegetation it increased again. Analysis of the nitrogen-fixing activity revealed the highest values for microbial strains isolated from the root nodules collected at the early stages of the macrosymbiont development, while it was lower in the strains isolated at the end of vegetation. At different stages of their development legumes may probably use different strategies for selection of microsymbionts. [ABSTRACT FROM AUTHOR]

The functional activity of different phylogenetic variants of the transcriptional activator of nitrogen fixation genes in the cells of root nodule bacteria (rhizobia) of different taxa was analyzed. For this purpose, recombinant strains of root nodule bacteria of the genera Mesorhizobium, Ensifer (Sinorhizobium), and Rhizobium were created using genetic engineering constructs based on the plasmid pJN105. This plasmid contains different phylogenetic variants of the nifA gene typical for bacteria of the genera Mesorhizobium, Ensifer, and Rhizobium under the control of the ParaBAD bacterial promoter. It was shown that in free-living recombinant cells of all three bacterial genera, the introduction of an additional active copy of the nifA gene to their genome resulted in emergence of detectable nitrogenase activity. The level of nitrogenase activity was not directly related to the phylogeny of the introduced nifA gene, which is most likely explained by the universality of the product of this gene within the studied group of bacteria. The data obtained indicate the possibility of combinatorial processes in the evolution of nitrogen fixation genes. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of the RapA1 protein on growth-stimulating activity, biofilm formation, and root colonization by rhizobia, strains Rhizobium leguminosarum Pvu5, VSy12, Thy2, TPr4 and R. galegae 0702 were transformed with the pJN105TurboRapA1GFP vector, providing for constitutive expression of the rapA1 and gfp genes. Constitutive expression of the rapA1 gene was shown to result in more efficient biofilm formation on inert surfaces and to promote microcolony formation on plant root surfaces. Analysis of auxin production by wild and transformed strains revealed decreased auxin synthesis in all transformed strains, except for R. leguminosarum Thy2. Growth-stimulating activity of the wild and transformed strains did not correlate with the amount of auxins produced in vitro. [ABSTRACT FROM AUTHOR]

Abstract—The importance of root nodule bacteria in biotechnology is determined by their distinctive feature: symbiotic nitrogen fixation resulting in the production of organic nitrogen-containing compounds. While interacting with host legume plants, the cells of these bacteria undergo global changes at all levels of expression of genetic information leading to the formation in root nodules of so-called bacteroids functioning as nitrogen fixation factories. The molecular mechanisms underlying plant-microbial symbiosis are actively investigated, and one of the most interesting and poorly studied aspects of this problem is the species-specificity of interaction between root nodule bacteria and host plants. In this work we have performed the proteomic analysis of the Sinorhizobium meliloti bacteroids isolated from two legume species: alfalfa (Medicago sativa L.) and yellow sweet clover (Melilotus officinalis L.). It has been shown that the S. meliloti bacteroids produce a lot of proteins (many of them associated with symbiosis) in a host-specific manner, i.e., only in certain host plant species. It has been demonstrated for the first time that the levels of expression in bacteroids of the genes encoding the ExoZ and MscL proteins responsible for the synthesis of surface lipopolysaccharides and formation of a large conductance mechanosensitive channel, respectively, depend on a host plant species that confirms the results of proteomic analysis. Overall, our data show that the regulation of bacteroid development by the host plant has species-specific features. [ABSTRACT FROM AUTHOR]

In silico analysis of open reading frames of genomic islands of Sinorhizobium meliloti Rm1021 was performed. This strain is a typical representative of soil bacteria forming nitrogen-fixing symbiosis with legume host plants from the alfalfa cross-inoculation group. It was demonstrated that genomic islands had mosaic structure, in which blocks of functional genes, IS-elements and noncoding RNA alternated. Genomic islands contained as well the components of T4SS and T4CP systems, and lacked systems of conjugative mobilization of islands. It was concluded that two of the three islands could be the variants of reduced integrative conjugative elements, and the third island represented a reduced integrated conjugative transposon. Site-specific integration of islands occurred into a 15-31 bp sequence (depending on the island) localized at the 3′-end of the tRNA gene, which is then shifted rightward, while the remaining part of the tRNA gene is completed by a similar sequence that exists in the island. A suggestion on the existence of “speciesspecific insertion hotspots” for genomic islands of root nodule bacteria was put forward. [ABSTRACT FROM AUTHOR]

Strain CCMM B554, also known as FSM-MA, is a soil dwelling and nodule forming, nitrogen-fixing bacterium isolated from the nodules of the legume Medicago arborea L. in the Maamora Forest, Morocco. The strain forms effective nitrogen fixing nodules on species of the Medicago, Melilotus and Trigonella genera and is exceptional because it is a highly effective symbiotic partner of the two most widely used accessions, A17 and R108, of the model legume Medicago truncatula Gaertn. Based on 16S rRNA gene sequence, multilocus sequence and average nucleotide identity analyses, FSM-MA is identified as a new Ensifer meliloti strain. The genome is 6,70 Mbp and is comprised of the chromosome (3,64 Mbp) harboring 3574 predicted genes and two megaplasmids, pSymA (1,42 Mbp) and pSymB (1,64 Mbp) with respectively 1481 and 1595 predicted genes. The average GC content of the genome is 61.93%. The FSM-MA genome structure is highly similar and co-linear to other E. meliloti strains in the chromosome and the pSymB megaplasmid while, in contrast, it shows high variability in the pSymA plasmid. The large number of strain-specific sequences in pSymA as well as strain-specific genes on pSymB involved in the biosynthesis of the lipopolysaccharide and capsular polysaccharide surface polysaccharides may encode novel symbiotic functions explaining the high symbiotic performance of FSM-MA. [ABSTRACT FROM AUTHOR]

The root nodule bacteria were isolated from three different leguminous plants belonging to the Fabaceae family such as Cajanus cajan, Lablab purpureus and Vigna unguiculata using YEMA medium and identified. The isolates were submitted to 16S rRNA and PCR- RFLP typing. A representative sample was further submitted to sequence analysis of 16S rRNA. Isolates were assigned to two genera and were related to Rhizobium spp. (75%) and Bacillus spp. (25%) respectively. This study opens the doors to researchers to do specific studies on this root nodule bacteria which are symbiotic with these legume plants in this area for their antibacterial activity, medicine and food application, and sustainable agriculture. Rhizobium and other beneficial microbes may be used as biofertilizers as a substitute for chemical fertilizers. [ABSTRACT FROM AUTHOR]

Eleven extra-slow-growing strains were isolated from nodules of the relict legume Vavilovia formosa growing in North Ossetia (Caucasus) and Armenia. All isolates formed a single rrs cluster together with the type strain Tardiphaga robiniae LMG 26467, while the sequencing of the 16S-23S rDNA intergenic region (ITS) and housekeeping genes glnII, atpD, dnaK, gyrB, recA and rpoB divided them into three groups. North Ossetian isolates (in contrast to the Armenian ones) were clustered separately from the type strain LMG 26467. However, all isolates were classified as T. robiniae because the DNA-DNA relatedness between them and the type strain LMG 26467 was 69.6 % minimum. Two symbiosis-related genes ( nodM and nodT) were amplified in all isolated Tardiphaga strains. It was shown that the nodM gene phylogeny is similar to that of ITS and housekeeping genes. The presence of the other symbiosis-related genes in described Tardiphaga strains, which is recently described genus of rhizobia, as well as their ability to form nodules on any plants are under investigation. [ABSTRACT FROM AUTHOR]

Summary Inoculation with beneficial soil microorganisms has the potential to enhance success of restoration, particularly in harsh Mediterranean-type ecosystems (MTEs). We investigated the effects of microorganisms (mycorrhizal fungi and root nodule bacteria) and planting material (seed and nursery-raised seedlings) on early establishment and growth of two key postdisturbance colonizing species with different life histories, life forms and functional types ( Eucalyptus gomphocephala and Acacia saligna) under field conditions. Establishment and growth were monitored at 13 months, following the first MTE drought period. For E. gomphocephala, establishment was higher for seedlings (81%) than for seeding (7.5%). Inoculation with ectomycorrhizal fungal spores was not beneficial. For A. saligna, establishment was also higher for seedlings (84%) than for seeding (42.5%). Mycorrhizal fungal inoculum had no effect on establishment or growth. This study has shown that in harsh MTE conditions, the use of seedlings is more effective than seeding in degraded woodlands even when attempting to reintroduce key colonizing species. The microorganism treatments tested did not result in significant improvement in establishment or growth. [ABSTRACT FROM AUTHOR]

The genetic diversity and phylogeny of root nodule bacteria entering into symbiosis with bitter peavine Lathyrus vernus (L.) Bernh. ( Fabaceae) growing in various regions of the Republic of Bashkortostan were studied. RAPD analysis revealed a high degree of polymorphism of the DNA of the isolated strains giving evidence of the heterogeneity of the microorganisms in question. The study of the phylogeny of microsymbionts based on comparative analysis of the nucleotide sequences of 16S rRNA genes showed that the bacteria isolated from the plant nodules of L. vernus growing on the territory of Ufa and Beloretsk raions belonged to the species Rhizobium leguminosarum, whereas the microsymbionts of L. vernus growing on the territory of Tatyshly raion belonged to the species Rhizobium tropici,@ except for several strains of Rhizobium leguminosarum [ABSTRACT FROM AUTHOR]

Abstract: The vktA catalase gene, which had been cloned from Vibrio rumoiensis S-1T having extraordinarily high catalase activity, was introduced into the root nodule bacterium, Rhizobium leguminosarum bv. phaseoli USDA 2676. The catalase activity of the vktA-transformed R. leguminosarum cells (free-living) was three orders in magnitude higher than that of the parent cells and this transformant could grow in a higher concentration of exogenous hydrogen peroxide (H2O2). The vktA-transformant was inoculated to the host plant (Phaseolus vulgaris L.) and the nodulation efficiency was evaluated. The results showed that the nitrogen-fixing activity of nodules was increased 1.7 to 2.3 times as compared to the parent. The levels of H2O2 in nodules formed by the vktA-transformant were decreased by around 73%, while those of leghemoglobins (Lba and Lbb) were increased by 1.2 (Lba) and 2.1 (Lbb) times compared with the parent. These results indicated that the increase of catalase activity in rhizobia could be useful to improve the nitrogen-fixing efficiency of nodules by the reduction of H2O2 content concomitantly with the enhancement of leghemoglobins contents. [ABSTRACT FROM AUTHOR]

The South African legumes Lotononis bainesii, L. listii and L. solitudinis are specifically nodulated by highly effective, pink-pigmented bacteria that are most closely related to Methylobacterium nodulans on the basis of 16S rRNA gene homology. Methylobacterium spp. are characterized by their ability to utilize methanol and other C1 compounds, but 11 Lotononis isolates neither grew on methanol as a sole carbon source nor were able to metabolize it. No product was obtained for PCR amplification of mxaF, the gene encoding the large subunit of methanol dehydrogenase. Searches for methylotrophy genes in the sequenced genome of Methylobacterium sp. 4-46, isolated from L. bainesii, indicate that the inability to utilize methanol may be due to the absence of the mxa operon. While methylotrophy appears to contribute to the effectiveness of the Crotalaria/M. nodulans symbiosis, our results indicate that the ability to utilize methanol is not a factor in the Lotononis/ Methylobacterium symbiosis. [ABSTRACT FROM AUTHOR]

Abstract: The mathematical model for evolution of the plant–microbe facultative mutualistic interactions based on the partners’ symbiotic feedbacks is constructed. Using the example of rhizobia–legume symbiosis, we addressed these feedbacks in terms of the metabolic exchange resulting in the parallel improvements of the partners’ fitness (positive feedbacks). These improvements are correlated to the symbiotic efficiency dependent on the ratio of N2-fixing bacterial strains (“genuine mutualists”) to the non- N2-fixing strains (“symbiotic cheaters”) in the root nodules. The computer experiments demonstrated that an interplay between the frequency-dependent selection (FDS) and the Darwinian (frequency-independent) selection pressures implemented in the partners’ populations ensures an anchoring or even domination for the newly generated host-specific mutualists (which form N2-fixing nodules only with one of two available plant genotypes) more successfully than for the non-host-specific mutualists (which form N2-fixing nodules with both plant genotypes). The created model allows us to consider the mutualistic symbiosis as a finely balanced polymorphic system wherein the equilibrium in bacterial population may be shifted in favor of “genuine mutualists” due to the partner-stipulated selection for an improved symbiotic efficiency implemented in the plant population. [Copyright &y& Elsevier]

Different species of Rhizobium were successfully introduced into the extracellular slime of Nostoc paludosum (Kütz) Elenk, strain 18; cyanobacteria did not eliminate them and exhibited no specificity to the introduced species. Both partners were shown to exist in a self-sufficient manner in an artificial consortium, the stability of which is determined by the technology of growing the cultures in collections. Cyanobacteria act as carriers of introduced satellites, providing contact with the inoculated material through the slime, and increase the nitrogen-fixing ability of legume plants due to the increase of the number and activity of nodules. The fact of penetration of cyanobacterial hormogonia into the nodules has been noted. The treatment of seeds by the consortium resulted in an increase of the harvest as compared with the standard methods of nitragin treatment of legumes. [ABSTRACT FROM AUTHOR]

Abstract: Siderophores are ferric specific ligands that are involved in receptor specific iron transport into bacteria. Partially purified siderophores from 37 different rhizospheric bacterial isolates, and 17 Cajanus cajan root nodule isolates were tested for their utilization by the 17 nodule isolates as test organisms. Significant variation in the siderophore cross-utilization pattern was observed. Catecholate siderophores were produced predominantly by nodule isolates whereas rhizospheric isolates produced catecholates, as well as hydroxamates. The quantity of hydroxamate produced was higher than that of catecholates. Considerable variation was observed with respect to siderophore cross-utilization amongst nodule isolates obtained from a particular location. Isolates collected from different nodules of same plant also showed considerable variation with respect to siderophore cross-utilization. Isolates, which showed, higher siderophores cross-utilizing ability, when tested for homologous (from other nodule bacteria) siderophores also gave good cross-utilization of heterologous (from non-nodule rhizospheric bacteria) siderophores. Isolate GHU(iii), the highest cross-utilizer of homologous and heterologous siderophores showed a significant increase in growth in the presence of exogenously added siderophores. Similar results were observed during the co-inoculation studies with rhizospheric isolate under iron-limited condition. Both isolates GAU(1)1 and AP(6)4, low cross-utilizers of siderophores, failed to show growth increase in response to co-inoculation and addition of siderophores. The iron regulated outer membrane protein (IROMP) profiles of strains showing maximum or least cross-utilization did not differ. The significance of these findings in context to survivability under natural conditions and the possible reasons accounting for high siderophore cross-utilizing status of isolate GHU(iii) is discussed. [Copyright &y& Elsevier]

Abstract: Coffee (Coffea arabica) production provides a source of income for small-scale farmers in Chiapas, Mexico. Organic production regulations prohibit the use of synthetic nitrogen (N) fertilizers, therefore farmers are dependent upon N-sources accepted by organic certification agencies. In the state of Chiapas, little is known about effectiveness of rhizobia and nodule development, location and structure of the common coffee shade tree genus Inga. The objectives of this study were to (1) evaluate the symbiotic effectiveness of selected rhizobia isolates as inoculants for Inga oerstediana under greenhouse and field conditions, (2) describe the morphological and histochemical characteristics of I. oerstediana root nodules, and (3) apply the 15N natural abundance technique to investigate nitrogen fixation in two stands of I. oerstediana of different ages intercropped with C. arabica. To meet objectives one and two, we assessed shoot biomass, nodule number, nodule mass and total shoot N of inoculated I. oerstediana seedlings at 90 and 150 days after planting (DAP) in the greenhouse and field. Light microscopy, and in situ hybridization of nodule sections for leghemoglobin and Nif H cDNA determination were used to describe nodule morphology and histology. Results indicated that tested isolates appear not to be fixing N2 150 DAP and inoculation with isolated bacteria, and that inoculated treatment nodules lacked leghemoglobin and Nif H mRNA transcript, however contained infected bacteroids. An unidentified brown-pigmented granular substance was present in all nodules examined. I. oerstediana appears slow to nodulate, with negligible nodulation at 90 DAP, and limited nodulation at 150 DAP. Using the natural abundance method to meet objective three, recycling of fixed N in older 5–7 year plots is thought to have caused great 15N value variation in both reference and leguminous trees and data could not be used to estimate % N derived from Biological Nitrogen Fixation (BNF). I. oerstediana found in younger 1–3 year old plots was found to derive 20% of its N from BNF. As fixation appears to be low in young Inga, recommendations for organic C. arabica shade tree management include supplementation of N during early growth of Inga-C. arabica intercrop, and longer-term nodulation studies combined with additional N2-fixation assessment using 15N natural abundance methods. [Copyright &y& Elsevier]

Abstract: The leguminous tree genus Inga is thought to be critical for providing N to certified organic coffee shrubs that commonly grow beneath its shade in the state of Chiapas, Mexico. Organic certification prohibits use of synthetic N fertilizers, necessitating understanding of the Inga–rhizobia symbiosis. The objectives of this study were to: (1) establish a collection of isolates from Inga sp. nodules found on organic coffee farms in Chiapas, Mexico; (2) use phenotypic and genotypic approaches to characterize these isolates, and (3) examine cross-inoculation patterns of strains isolated from Inga sp. with other Inga species and N2-fixing trees. Eighty-three strains were isolated from root nodules of Inga oerstediana, Inga pavoniana and an unknown species of Inga. Aside from isolates of I. pavoniana, Inga isolates demonstrate characteristics consistent with Bradyrhizobium. Dendrograms generated using phylogenetic and phenotypic traits showed strains to exhibit significant diversity, even among strains originating from the same farm. Strains isolated from I. pavoniana were 95% similar, and displayed strikingly different characteristics from strains isolated from other species. Cross-inoculation experiments used three Inga strains (cowpea miscellany CB756, and isolates from I. oerstediana and I. sp.) as inoculants with I. edulis, I. fuellii, Acacia mangium, Acacia koa, Vigna unguculata and Gliricidia sepium. All three strains formed nodules containing leghaemoglobin with V. unguculata, while isolates from I. oerstediana, Inga sp. and cowpea miscellany formed nodules with I. feulli and I. edulis, but not with A. mangium and G. sepium. A. koa formed nodules containing leghaemoglobin when inoculated by cowpea miscellany strain CB756 and the strain from Inga sp., but nodules formed with the strain isolated from I. oerstediana did not contain leghaemoglobin. One and two-way ANOVA results showed that no mean biomass of inoculated seedlings was significantly greater than the −N control for each of A. koa, G. sepium, A. mangium (p <0.001), supporting our hypothesis that inoculation with non-Inga strains would have no effect on biomass production. We suggest that great spatial variation exists among Inga isolates from organic coffee farms in the Chiapas highland region, both between and within farms, and that more research is needed to identify reasons for the genetic distribution and function of Inga symbionts. [Copyright &y& Elsevier]

The effect of seed vernalization (2–3°C; 36 days) and irradiation intensity during vegetation of field bean upon growth and maximum leaf photosynthesis (Pmax) as well as specific (SNA) and total nitrogenase activity (TNA) of root nodules was investigated. The measurements were performed at the initial stage of pod development of varieties with undetermined (cv. Nadwiśański) and determined (cv. Tibo) growth habit. In comparison with plants in shading, those which grew in full irradiation produced larger leaf area and more dry weight, achieving higher Pmax values. Stimulation of leaf area enlargement and dry weight increase, especially in respect to the dry weight of underground parts had a positive and significant effect upon TNA value. Accumulation of dry weight was higher in vernalized than non-vernalized plants, but only in the case of cv. Nadwiślański, in full irradiation conditions. In the case of plants grown in poorer irradiation conditions TNA values were about 68 % (cv. Nadwiślański) and 54 % (cv. Tibo) lower, due to significant limitation of root nodules. TNA value of vernalized cv. Nadwiślański plants was 66 % higher in comparison with non-vernalized plants. However, the effect was visible only in full irradiation conditions, due to simultaneous greater intensity of root nodules production and higher SNA value. A positive effect of vernalization could also be observed in the decrease of a negative correlation between dry weight of root nodules and SNA in both varieties. [ABSTRACT FROM AUTHOR]

Field beans of indeterminate (cv. Nadwiślański) and determinate (cv. Tibo) growth habits were grown on field plots with a density of 20, 40 and 80 plants m-2 at two levels of nitrogen fertilization: low (20 kg N ha-1) and very high (150 kg N ha-1). At the phase of intense pod growth the number and the dry matter weight of root nodules as well as their nitrogenase activity and some features of the plants growth were determined, and in the period of ripeness the components of seed yield were established. It was found that increased density of sowing as well as the high level of nitrogen fertilization inhibited the growth and development of root nodules and limited their nitrogenase activity in both cultivars. Plants of both varieties were characterized by a similar potential of forming the root nodules, however, in plants of the cv. Tibo the nitrogenase activity of nodules was much lower than in the cv. Nadwiślański. Increased population density of the plants has in both varieties given increased seed yield when calculated per m² of the soil, compensating in excess the depression of the seed yield from one plant. Such compensation did not occur in the case of the depression of nitrogen fixation under intense nitrogen fertilization. [ABSTRACT FROM AUTHOR]

The plants of field bean var. Nadwiślański were detopped after about 1 month since the beginning of flowering and after that all flower buds were removed from some plants. The effect of a change in the trophic balance on the setting and subsequent growth of root nodules was studied. The removal of pods had the greater effect on the increase in the weight of the remaining organs than the detopping of plants Detopping retarded the ageing of the plants and delayed the phase of the greatest reduction of the number of pods. The detopping of plants revealed their considerable compensative possibilities in terms of production of the pod weight and the potential of leaves for biomass production. The data obtained indicate that plant detopping may disturb the root--bacteria exchange of signals, necessary to initiate the nodule development, while the further growth of nodules depends, above all, on the amount of available photosynthates. A very high correlation between the dry weight of the whole plant to the dry weight of leaves ratio and the weight of nodules was observed. It proves the importance of the trophic balance of the plant for the root nodule weight production. [ABSTRACT FROM AUTHOR]

Amyloids are protein fibrils with a highly ordered spatial structure called cross-β. To date, amyloids were shown to be implicated in a wide range of biological processes, both pathogenic and functional. In bacteria, functional amyloids are involved in forming biofilms, storing toxins, overcoming the surface tension, and other functions. Rhizobiales represent an economically important group of Alphaproteobacteria, various species of which are not only capable of fixing nitrogen in the symbiosis with leguminous plants but also act as the causative agents of infectious diseases in animals and plants. Here, we implemented bioinformatic screening for potentially amyloidogenic proteins in the proteomes of more than 80 species belonging to the order Rhizobiales. Using SARP (Sequence Analysis based on the Ranking of Probabilities) and Waltz bioinformatic algorithms, we identified the biological processes, where potentially amyloidogenic proteins are overrepresented. We detected protein domains and regions associated with amyloidogenic sequences in the proteomes of various Rhizobiales species. We demonstrated that amyloidogenic regions tend to occur in the membrane or extracellular proteins, many of which are involved in pathogenesis-related processes, including adhesion, assembly of flagellum, and transport of siderophores and lipopolysaccharides, and contain domains typical of the virulence factors (hemolysin, RTX, YadA, LptD); some of them (rhizobiocins, LptD) are also related to symbiosis. [ABSTRACT FROM AUTHOR]