Azolla cultivation enables phosphate extraction from inundated former agricultural soils

To combat the global loss of wetlands and their essential functions, the restoration and creation of wetlands is imperative. However, wetland development is challenging when soils have been in prolonged agricultural use, often resulting in a substantial nutrient legacy, especially of phosphorous (P). Inundating these soils typically leads to P mobilization, resulting in poor water quality and low biodiversity recovery. As a potential novel means to overcome this challenge, we tested whether cultivation of the floating fern Azolla filiculoides could simultaneously extract and recycle P, and provide a commercial product. Azolla has high growth rates due to the nitrogen fixing capacity of its microbiome and is capable of luxury consumption of P. Azolla cultivation may also accelerate soil P mobilization and subsequent extraction by causing surface water anoxia and the release of iron-bound P. To test this approach, we cultivated Azolla on 15 P-rich former agricultural soils in an indoor mesocosm experiment. Soils were inundated and either left unvegetated or inoculated with A. filiculoides during two 8-week cultivation periods. Biomass was harvested at different intervals (weekly/monthly/bimonthly) to investigate the effect of harvesting frequency on oxygen (O2) and nutrient dynamics. We found that Azolla attained high growth rates only on soils with high mobilization of labile P, as plant cover did not reduce surface water O2 concentrations in the first phase after inundation. This concurred with low porewater iron to P ratios (<10) and high porewater P concentrations. A. filiculoides cultivation substantially reduced surface water nutrient concentrations and extracted P at rates up to 122 kg ha-1 yr-1. We conclude that rapid P extraction by A. filiculoides cultivation is possible on soils rich in labile P, offering new perspectives for wetland rehabilitation. Additional field trials are recommended to investigate long-term feasibility, seasonal variations, and the influence of potential grazers and pathogens.

The crane fly glycosylated triketide δ-lactone cornicinine elicits akinete differentiation of the cyanobiont in aquatic Azolla fern symbioses

The restriction of plant-symbiont dinitrogen fixation by an insect semiochemical had not been previously described. Here we report on a glycosylated triketide δ-lactone from Nephrotoma cornicina crane flies, cornicinine, that causes chlorosis in the floating-fern symbioses from the genus Azolla. Only the glycosylated trans-A form of chemically synthesized cornicinine was active: 500 nM cornicinine in the growth medium turned all cyanobacterial filaments from Nostoc azollae inside the host leaf-cavities into akinetes typically secreting CTB-bacteriocins. Cornicinine further inhibited akinete germination in Azolla sporelings, precluding re-establishment of the symbiosis during sexual reproduction. It did not impact development of the plant Arabidopsis thaliana or several free-living cyanobacteria from the genera Anabaena or Nostoc but affected the fern host without cyanobiont. Fern-host mRNA sequencing from isolated leaf cavities confirmed high NH4-assimilation and proanthocyanidin biosynthesis in this trichome-rich tissue. After cornicinine treatment, it revealed activation of Cullin-RING ubiquitin-ligase-pathways, known to mediate metabolite signaling and plant elicitation consistent with the chlorosis phenotype, and increased JA-oxidase, sulfate transport and exosome formation. The work begins to uncover molecular mechanisms of cyanobiont differentiation in a seed-free plant symbiosis important for wetland ecology or circular crop-production today, that once caused massive CO2 draw-down during the Eocene geological past.

Azolla ferns testify: seed plants and ferns share a common ancestor for leucoanthocyanidin reductase enzymes

Questions about in vivo substrates for proanthocyanidin (PA) biosynthesis and condensation have not been resolved and wide gaps in the understanding of transport and biogenesis in 'tannosomes' persist. Here we examined the evolution of PA biosynthesis in ferns not previously reported, asking what PAs are synthesised and how. Chemical and gene-expression analyses were combined to characterise PA biosynthesis, leveraging genome annotation from the floating fern Azolla filiculoides. In vitro assay and phylogenomics of PIP-dehydrogenases served to infer the evolution of leucoanthocyanidin reductase (LAR). Sporophyte-synthesised (epi)catechin polymers, averaging only seven subunits, accumulated to 5.3% in A. filiculoides, and 8% in A. pinnata biomass dry weight. Consistently, a LAR active in vitro was highly expressed in A. filiculoides. LAR, and paralogous fern WLAR-enzymes with differing substrate binding sites, represent an evolutionary innovation of the common ancestor of fern and seed plants. The specific ecological niche of Azolla ferns, a floating plant-microbe mat massively fixing CO₂ and N₂ , shaped their metabolism in which PA biosynthesis predominates and employs novel fern LAR enzymes. Characterisation of in vivo substrates of these LAR, will help to shed light on the recently assigned and surprising dual catalysis of LAR from seed plants.

Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition

Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO₂ and fix N₂ at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKC^C homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKC^C TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.

Fukushima radionuclides at air filter and rain water samples collected from Istanbul and their atmospheric removal time

Accident at Fukushima Daiichi Nuclear Power Plant (FDNPP) is one of the most serious accident in the world after Chernobyl accident. Following the continuing release of radionuclides in air after FDNPP, traces of fission products ((131)I, (134)Cs and (137)Cs) were recorded in the air filter and rain water samples collected from the ÇNAEM area at İstanbul on 4 April 2011. Airborne particle samples were collected daily in air filters and radio assayed with a high purity germanium detector. The fission products (131)I, (134)Cs and (137)Cs were measured with the maximum activity concentrations of 1.03±0.08, 0.25±0.03 and 0.23±0.03 mBq m(-3), respectively. For determination of the origin of the releases the (134)Cs/(137)Cs ratio was calculated between 1.09 and 0.85. The authors find removal times for (137)Cs of 8.13 d, (134)Cs of 7.25 d and (131)I of 6.82 d.

Determination and phylogenetic analysis of canine distemper virus in dogs with nervous symptoms in Turkey

In the present study, canine distemper virus (CDV) was investigated in 20 dogs having nervous signs arousing the clinical suspicion of canine distemper (CD). A total of 13 animals (65%) were stray dogs and had no accurate record about the vaccination history. Clinical examinations revealed that the majority (85%) of the animals showed systemic form characterised by predominantly nervous symptoms accompanied by mild respiratory system signs whilst the remaining cases (15%) recorded mainly respiratory distress. CDV RNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) only in 45% of the suspected cases. Phylogenetic analysis of partial nucleotide sequence of the P gene coding region revealed that the virus is closely related to European strains. Immune responses in 13 cases (65%), which were detected by dot-ELISA, indicated inefficient levels for neutralising functions against CDV. It was postulated that this response could have been mediated by either previous vaccination or mild infection with field strains.

Experimental studies on the biokinetics of 134Cs and 24Am in mussels (Mytilus galloprovincialis)

The biokinetics of 134Cs and 241Am in mussel species contaminated through water pathway has been studied under laboratory conditions. At equilibrium, the concentration factors for 134Cs and 241Am in small and large mussels were 2.80 and 2.57 and 200 and 150, respectively. The concentration factor of 134Cs in soft parts of the mussels was significantly high than whole body and shell tissue. However, the concentration factors of 241Am in soft parts and shell tissue samples were found to have similar rates. The depuration kinetics of the radionuclides were described by two-component exponential models. The biological half-lives at slow components between small and large mussels did not change significant, and were found to be 46.8-46.5 and 72.2-75.3 days for 134Cs and 241Am. The depuration kinetics of 134Cs and 241Am in soft parts described a single-component exponential model and the biological half-lives were found to be 29.4 and 41.1 days, respectively.

Phenytoin hypersensitivity syndrome

Phenytoin hypersensitivity syndrome (PHS) is a rare, and important entity characterized by rash, fever, lymphadenopathy, leukocytosis with atypical lymphocytes, eosinophilia and associated hepatitis. In this article, we present the clinical, laboratory and histopathologic results of 5 cases of PHS. In therapy, pheyntoin was stopped and sodium valproate (10-20 mg/kg day) was started. Additionally, prednisolone was given in two patients who had not resolved eruption with conservative therapy.

Prevalence of hepatitis C virus antibodies and cryoglobulinemia in patients with leukocytoclastic vasculitis

BACKGROUND

Several dermatologic manifestations of hepatitis C virus (HCV) infection have been described. The association of HCV infection, essential mixed cryoglobulinemia and leukocytoclastic vasculitis (LV) have been published mainly in case reports.

OBJECTIVE

The aim of the present study was to determine the prevalence of HCV infection and cryoglobulinemia in patients with LV.

METHODS

Twenty-five cases of LV were tested for anti-HCV antibodies by means of a third-generation enzyme-linked immunosorbent assay, and cryoglobulins were detected by the precipitation method. Thirty healthy volunteers served as control group.

RESULTS

Anti-HCV antibodies were detected in 2/25 patients with LV (8%) and none of the control group. Cryoglobulinemia was detected in 1 patient with LV and none in the control group.

CONCLUSION

Although no significant difference between patients and the control group was detected, the prevalence of anti-HCV antibodies in LV patients is as high as 8%. Considering this, it seems reasonable to investigate the presence of HCV in unexplained cases of LV.

Penile pyoderma gangrenosum

Pyoderma gangrenosum is a rare ulcerating inflammatory skin disease. Genital involvement has been rarely reported. We report a 24-year-old man with penile pyoderma gangrenosum who was treated with systemic corticosteroids.

Itraconazole therapy in lymphocutaneous sporotrichosis: a case report and review of the literature

A 24-year-old white man had a six-month history of nontender nodules on the dorsal aspect of the right hand. The lesions were diagnosed as lymphocutaneous sporotrichosis based on clinical appearance, histopathologic examinations, and fungal culture. Therapy with itraconazole was started. Considerable improvement was recorded after two months, when all of the lesions diminished in size and were no longer nodular in appearance.

Natural effective half-life of 137Cs in tea plants

Contamination levels and variation of 137Cs in tea plant leaves from 1986-1992 were determined over the coast line of the Eastern Black Sea region in Turkey. The decrease of 137Cs radionuclide concentration in tea plant leaves may be described by a double exponential function with 94.8% activity lost with a Teff of 125 d and 5.2% activity lost with a Teff of 1,114 d.