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Metabolic potential of microorganisms associated with the halophyte Aster tripolium L. in saline soils

100%

Szymanska S. , Piernik A. , Hrynkiewicz K.

tom 18

Increased soil salinization may be caused by a natural (e.g. climate change) and anthropogenic (e.g. improper fertilization and irrigation of agricultural land) factors. The submitted work assumes that microorganisms associated with plant halophytes have a unique metabolic properties that can stimulate plant growth under salt stress. The aim of the study was to determine the abundance and metabolic biodiversity of endophytic and rhizosphere microorganisms co-existing with Aster tripolium L. and compare them with the properties of soil microorganisms not affected by plant roots at a salty meadows in the vicinity of a soda factory (central Poland). In order to select halotolerant and halophilic microorganisms culture medium was enriched with various concentrations of NaCl (0, 100, 200, 400, 600 mM NaCl). Total metabolic activity of endophytic, rhizosphere and soil populations was measured to compare the community-level physiological profiles. Results of our study revealed that bacterial and fungal density increased in the following order: endophytes < soil < rhizosphere. Only the highest concentration (600 mM) of NaCl decreased the number of microorganisms. The highest total microbial metabolic activity was observed for the rhizosphere, while the activity of endophytes was higher compare to soil populations. To carbon sources which significantly differentiated zones belonged: D-lactose, 4-hydroxybenzoic acid and L-asparagine. The results are preliminary studies leading to the development of inoculum based on selected microbial halotolerant and halophilic strains which can be used in agriculture and/or recultivation of saline soils.

Response of birch and alder root endophytes as well as rhizosphere and bulk soil microorganisms to heavy metal pollution

100%

Zloch M. , Kowalkowski T. , Szymanska S. , Hrynkiewicz K.

Polish Journal of Ecology

2014

tom 62

nr 1

Research on soil microorganisms associated with plant roots (endophytes) and their outside habitats (rhizosphere, soil) under exposure to high concentrations of heavy metals in the environment may contribute to an increased knowledge about the effects of unfavorable pollutants in the natural ecosystem and improve the efficiency of remediation processes of degraded soils. The main goal of our study was to evaluate properties of microbial populations inhabiting different but spatially closed habitats: interior of the tree roots – endophytes (Betula pendula L. and Alnus glutinosa L.), rhizosphere and soil not influenced by plant roots at two heavy metal polluted areas in southern Poland where the content of cadmium, lead and zinc ranged 9.2–14.9, 26.2–75.1 and 1080–1559 mg∙kg–1 of dried soil, respectively. In our experiment, we analyzed their density as well as determined the total metabolic activity and ability for utilization of different carbon sources. The density of endophytes (5.76–7.16 log10 c.f.u. × g dw–1) was higher than the density of bacteria inhabiting outside habitats – the rhizosphere and soil (5.43–5.91 and 5.08–5.57 log10 c.f.u. × g dw–1, respectively) and was not affected by heavy metal content. However, the total metabolic activity of endophytic populations was strongly influenced by the physicochemical properties of the soil and was significantly lower at more contaminated site. In general, the metabolic activity of endophytes was ~15 times lower than the activity of rhizobacteria and at the same level or lower than the activity of soil microorganisms. Discriminant analysis revealed a higher utilization of α-Cyclodextrin and D-Xylose by microorganisms isolated from more polluted test site. The use of an artificial neural network (ANN) followed by principal component analysis (PCA) allowed the distinguishing of preferences in the utilization of carbon sources by microorganisms due to tree species but not the zone of isolation – endophytes, rhizosphere, soil. Our study revealed no significant impact of the metal concentrations present in the soil on the density of microorganisms (bacteria and fungi) inhabiting three analyzed zones (interior of the roots, rhziosphere, soil); however, their total metabolic activity was decreased in more contaminated site. Since the density of endophytes was higher compared to the number of bacteria present in the outside habitats (rhizosphere and soil), and their total metabolic activity was in general lower, we suggest a high specialization of microorganisms associated with the cellular spaces of plant roots compared to other microbial populations.

Gene expression profiling by cDNA-AFLP and identification of differentially expressed transcripts of bovine pituitary gland in growing bulls of dairy breeds

51%

Pareek C. S. , Pierzchala M. , Michno J. , Szymanska S. , Smoczynski R. , Jasik N. , Golebiewski M. , Tyburski J. , Urbanski P. , Goluch D. , Oprzadek J. , Zwierzchowski L. , Siriluck P. , Wimmers K.

nr 2

The study utilized age-dependent breed-specific gene expression profiling by cDNA-AFLP technique in identification of differentially expressed (DE) candidate genes for growth and development trait. Results revealed 15579 transcript derived fragments (TDFs) expressed in bovine pituitary gland tissue using 96 unique PCR reactions with primer combinations (PC) of TaqI-MseI for Polish Holstein (PH) and Polish Red (PR) dairy breeds. Gene expression profiling by cDNA-AFLP identified 1451,2877 and 4084 identically displayed (iDD), differentially displayed (DD) and single displayed (sDD) TDFs, respectively. In all transcript profiles, frequencies of DD TDFs were higher than that of iDD TDFs. A total of 60 DD TDFs bands were excised for PH (n=40) and PR (n=20) . Direct sequencing results revealed identification of 24 and 8 DE-TDFs sequences in Polish HF and PR. Based on the significance of BLAST and sequence alignment score, analysis 12 and 4 DE-TDFs sequences of PH and PR were excluded. Overall, 12 Polish HF and 4 PR breed specific DE-TDFs sequence expressed in bovine pituitary gland tissue were identified. The identified DE-TDFs sequences were represented in all bovine chromosomes, except BTA3, 4, 6, 7, 8, 9, 11, 12, 17, 18, 21, 22, 23, 25 and 26. TDF annotation results identified eight sequences that have BLAST hits to known annotated bovine genes and eight sequences to unannotated contig regions in latest gene ensemble database Btau 4,0. Two breed-specific target genes i.e., bovine glycophorin C (PH) and bovine arachidonate 5-lipoxygenase (Alox5) isoform 1 (PR) were validated by qRT-PCR. Within breed the age-dependent qRT-PCR analysis revealed that expression levels were differed significantly high (P<0.0001) with nine folds higher expression in young bulls at the age of 6 month (glycophorin C) and 9 month (Alox5 isoform 1). Between breed the qRT-PCR analyses revealed that the expression levels were highly significant for glycophorin C gene in PR and Alox5 isoform 1 gene in both breeds. It was concluded that gene expression profiling by cDNA-AFLP is a reliable technique for identification of trait-associated DE candidate genes, and helpful in elucidating and understanding molecular basis of postnatal growth and development of cattle.