Growth of Frankia AvcI1 on media containing between 80 as C-source

Uptake hydrogenase is an enzyme that is beneficial for nitrogen fixation in bacteria. Recent studies have shown that Frankia sp. has two sets of uptake hydrogenase genes, organized in synton 1 and synton 2. In the present study, phylogenetic analysis of the structural subunits of hydrogenase syntons 1 and 2 showed a distinct clustering pattern between the proteins of Frankia strains that were isolated from different host plants and non-Frankia organisms. The structural subunits of hydrogenase synton 1 of Frankia sp. CpI1, Frankia alni ACN14a, and F. alni AvCI1 were grouped together while those of Frankia spp. CcI3, KB5, UGL140104, and UGL011102 formed another group. The structural subunits of hydrogenase synton 2 of F. alni ACN14a and Frankia spp. CcI3 and BCU110501 grouped together, but those of Frankia spp. KB5 and CpI1, F. alni ArI3, and F. alniAvCI1 comprised a separate group. The structural subunits of hydrogenase syntons 1 and 2 of Frankia sp. EAN1pec were more closely related to those of non-Frankia bacteria, i.e., Streptomyces avermitilis and Anaeromyxobacter sp., respectively, than to those of other Frankia strains, suggesting the occurrence of lateral gene transfer between these organisms. In addition, the accessory Hyp proteins of hydrogenase syntons 1 and 2 of F. alni ACN14a and Frankia sp. CcI3 were shown to be phylogenetically more related to each other than to those of Frankia EAN1pec.

Grain yield of wheat (Triticum aestivum L.) under Mediterranean conditions is frequently limited by both high temperature and drought during grain growth. In this region, most rain falls during autumn and winter and water deficit emerges in the spring, resulting in a moderate stress for rainfed wheat around anthesis, which increases in severity throughout grain filling. Hence, selection of genotypes with high grain yield is the principal aim of wheat production in this region. In order to evaluation of yield and dry matter accumulation in wheat genotypes as affected by terminal drought stress, a factorial experiment based on randomized complete block design was conducted in Research Farm Islamic Azad University, Ardabil branch in 2009. Factors were: terminal drought stress by changing in planting date at three levels (12 October, 1 November and 21 November) with wheat (Triticu aestivum L.) genotypes at four levels (‘Azar-2’, ‘Sardari’, ‘Frankia’ and ‘Trakia’). The results showed that various levels of terminal drought stress affected yield, dry matter accumulation and leaf area index in wheat genotypes. Means comparisons showed that maximum grain yield (183.18 gr/m2) was obtained at the first of planting date or the least duration of confronting with thermal drought stress in ‘Azar-2’ genotype and minimum of it was obtained in the third planting date with ‘Trakia’ genotype due to the highest duration of confronting with thermal drought stress. Investigation of variances trend of dry matter accumulation indicated that in all of treatment compounds, it increased slowly until 190-200 days after sowing and then increased rapidly till 270-280 days after sowing. From 280 days after sowing till harvest time, it decreased due to increasing aging of leaves and decreasing of leaf area index. In the other hand, wheat genotypes had difference response to dry matter accumulation in confronting with thermal drought stress. Decrease in duration of terminal drought stress also significantly increased the leaf area index and the maximum of it was observed by the plots that were applied in the first planting date with ‘Azar-2’ genotype. In all of treatment compounds, LAI increased slowly until 190-200 days after sowing and then decreased slowly till 240-250 days after sowing. From 240-250 days after sowing till harvest time, it decreased rapidly due to hasten leaf senescence in confronting with terminal drought stress. Thus, it can be suggested that in order to increasing of grain yield, dry matter accumulation and leaf area index should be applied ‘Azar-2’ genotype with the first planting date(12 October ) in conditions of Ardabil Plain in Iran.

<i>Frankia Symbioses. Proceedings of the Worshop Held in Noordwijkerhout, The Netherlands, September 1, 1983, and in Wageningen, The Netherlands, September 5 and 6, 1983.</i>A. D. L. Akkermans , D. Baker , K. Huss-Danell , J. D. Tjepkema

Additional file 5: of Genomic, transcriptomic, and proteomic approaches towards understanding the molecular mechanisms of salt tolerance in Frankia strains isolated from Casuarina trees

The genus Alnus ( Betulaceae ) includes thirty-five species distributed across northern hemisphere (http://www.discoverlife.org). There are four species native to Europe: A. incana (grey alder), A. cordata (Italian or Corsica alder ), A. glutinosa (common or black alder) and A. viridis (green alder). In addition, A. rubra native to North America has been extensively planted in some European countries (Claessens, 2003). Alnus sp. plays important ecological roles. It is a pioneer genus, tolerant of high ground water levels and periodic flooding. A. glutinosa is the most common species and is present throughout Europe up to 1800 m. It is well adapted to wet sites and plays a vital role in riparian ecosystems as the root system helps to stabilise riverbanks reducing the effect of erosion (Webber et al., 2004). Black alder has a beneficial effect on soil (porosity, symbiosis with Frankia ), on water quality (filtration, purification) and also on fauna. It contributes to increase the biodiversity of birds and insects and its root system allows fish to shelter. Alnus incana is widely distributed in central and eastern Europe. In the south, it grows mainly in mountain areas. As it is a root sprout pioneer that tolerates both dry conditions and flooding, A. incana is very important for improving the stability of slopes and riverbanks (Jung & Blaschke, 2004). A. cordata and A. viridis are much less frequent species and are native to Corsica-Italy and mountains of central Europe, respectively (Claessens, 2003).

6 - Physiology and Biochemistry of Frankia in Culture

Population dynamics of Frankia in soil

A cross inoculation experiment was set up to examine the degree of coevolution between red alder (Alnus rubra Bong.) and Frankia populations and to test the competitive ability of red dlAer/Frankia combinations under different field conditions. Seedlings from high and low elevation populations from three watersheds in southwestern B. C. were inoculated with Frankia from the parent tree populations and planted into three high and three low elevation planting sites in the U.B.C.M.K. Research Forest. Seedlings were also inoculated with Frankia from trees near the planting sites. To examine the effect of neighbours on plant growth, each combination was planted with and without red alder neighbours. There was a significant interaction between planting elevation, parent and Frankia source. On low elevation sites, the final yield of plants inoculated with Frankia from their parent's elevation was half that of plants inoculated with Frankia from the opposite elevation. There was also an inverse relationship between yield and the proportion of fixed nitrogen in leaves for the different dldex/Frankia combinations. On high elevation sites, final yield was 3.6 times lower and nitrogen fixation levels were two times higher than on the low elevation sites. On these sites, plants inoculated with Frankia from their parents grew significantly more than plants inoculated with Frankia from any novel source. These data suggest that Frankia can evolve to a less mutualistic state and that expression of this effect depends on environmental conditions. It is predicted that less mutualistic Frankia will evolve in situations where the relationship with the host is likely to break down. The presence of neighbours reduced the growth of plants by half but had no effect on the interaction between plmt/Frankia combinations. There was no significant difference in plant yield when plants had neighbours from different parent elevations. In terms of productivity, total harvested plant mass per site ranged from 22,000 to 302 grams. Competitive intensity did not vary across sites, except that on the lowest productivity site, where no competitive effect was detectable, plants with neighbours were 44 % larger than plants without neighbours. On all other sites, the mass of plants with neighbours, relative to the mass of plants without neighbours, decreased over the course of the experiment. The plants in this experiment were attacked by woolly alder sawfly, Eriocampa ovata (L.). The sawflies attacked the fastest growing individuals on low elevation sites, resulting in decreased growth in late summer, 1993. This made observed differences between treatments conservative estimates of potential differences. The only exception to this pattern was that plants with neighbours had a higher degree of herbivore damage than plants without neighbours, confounding the effects of competition and herbivory.

Hydrogenase in &lt;i&gt;Frankia&lt;/i&gt; KB5: Expression of and relation to nitrogenase

The Nellix EndoVascular Aneurysm Sealing System