| 1. |
- Adomas, Aleksandra, et al.
(författare)
-
Comparative analysis of transcript abundance in Pinus sylvestris after challenge with a saprotrophic, pathogenic or mutualistic fungus
- 2008
-
Ingår i: Tree Physiology. - : Oxford University Press (OUP). - 0829-318X .- 1758-4469. ; 28:6, s. 885-897
-
Tidskriftsartikel (refereegranskat)abstract
- To investigate functional differences in the recognition and response mechanisms of conifer roots to fungi with different trophic strategies, Pinus sylvestris L. was challenged with a saprotrophic fungus Trichoderma aureoviride Rifai. The results were compared with separate studies investigating pine interactions with a pathogen, Heterobasidion annosum (Fr.) Bref. sensu stricto and an ectomycorrhizal symbiont, Laccaria bicolor Maire (Orton). Global changes in the expression of 2109 conifer genes were assayed 1, 5 and 15 days after inoculation. Gene expression data from a cDNA microarray were analyzed by the 2-interconnected mixed linear model statistical approach. The total number of genes differentially expressed compared with the uninfected control was similar after challenge with the pathogen and the ectomycorrhizal symbiont, but the number of differentially expressed genes increased over time, for H. annosum, and decreased for L. bicolor. Inoculation of pine roots with T aureoviride resulted overall in a much lower number of genes with changed transcript levels compared with inoculation with H. annosum or L. bicolor. Functional classification of the differentially expressed genes revealed that the ectomycorrhizal fungus triggered transient induction of defence-related genes. The response and induction of defence against the pathogen was delayed and the magnitude increased over time. Thus, there were specific transcriptional responses depending on whether the conifer roots were challenged with mutualistic, saprotrophic or pathogenic fungi. This suggests that pine trees are able to recognize diverse fungal species and specifically distinguish whether they are pathogenic, neutral or beneficial microbial agents.
|
|
| 2. |
- Asiegbu, F.O., et al.
(författare)
-
Isolation of a novel antimicrobal peptide gene (Sp-AMP) homologue from Pinus sylvestris (Scots pine) following infection with the root rot fungus Heterobasidion annosum
- 2003
-
Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 228:1, s. 27-31
-
Tidskriftsartikel (refereegranskat)abstract
- A new family of antimicrobial peptide homologues termed Sp-Amp has been discovered in Pinus sylvestris (Scots pine). This is the first report of such proteins to be characterized in a conifer species. Sp-AMP1 was identified in a substructured cDNA library of root tissue infected with the root rot fungus Heterobasidion annosum and encodes a mature peptide of 79 amino acid residues. Three additional members of the Sp-AMP family (Sp-AMPs 2–4) encode cysteine-rich proteins of 105 amino acids, each containing an N-terminal region with a probable cleavage signal sequence. Northern analysis confirmed that Sp-AMP expression is elevated in Scots pine roots upon infection with H. annosum. These peptides share 64% amino acid identity with a mature protein from Macadamia integrifolia (MiAMP1), which allowed us to build a homology model for preliminary analysis. Southern analyses further confirmed that several copies of the gene are present in the Scots pine genome. The potential significance of Sp-AMP in the H. annosum–conifer pathosystem is discussed.
|
|
| 3. |
- Asiegbu, F O, et al.
(författare)
-
Pathogen-inducible cDNAs from the interaction of the root rot fungus Heterobasidion annosum with Scots pine (Pinus sylvestris L.)
- 2005
-
Ingår i: Plant Science. - : Elsevier BV. - 0168-9452 .- 1873-2259. ; 168:2, s. 365-372
-
Tidskriftsartikel (refereegranskat)abstract
- Subtractive hybridization was used to select cDNAs representing genes that are differentially expressed during interaction of the necrotroph Heterobasidion annosum and its conifer host (Pinus sylvestris). We obtained 966 ESTs from the subtraction cDNA library, which included 509 singletons and 147 contigs. The sequences of 492 clones (51%) significantly matched National Centre for Biotechnology Information Database entries. Four hundred and seventy-four ESTs (49%) had not been previously described. The ESTs with moderate to high similarity scores based on BlastX were organized into categories based on their putative function. Among the genes identified, 16% were associated with metabolism and other cellular functions, 14% with cell rescue and defence and 39% were classified as unknown. Seven of the genes shared significant homology to fungal genes. A cDNA encoding an antimicrobial peptide (AMP) was the most abundant transcript representing 2% of the total sequenced clones. The expression pattern of five ESTs (peroxidase, anti-microbial peptide, resistance gene analogue, unknown protein, thaumatin) were analysed by virtual Northern blot, and confirmed elevated levels of the gene transcripts upon pathogen infection. These ESTs provide insight into the host-pathogen interaction and also represent a resource for future research on H. annosum-conifer pathosystems.
|
|
| 4. |
- Frykman, Susanne, et al.
(författare)
-
Synaptic and Endosomal Localization of Active gamma-Secretase in Rat Brain
- 2010
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:1, s. e8948-
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundA key player in the development of Alzheimer's disease (AD) is the gamma-secretase complex consisting of at least four components: presenilin, nicastrin, Aph-1 and Pen-2. gamma-Secretase is crucial for the generation of the neurotoxic amyloid beta-peptide (A beta) but also takes part in the processing of many other substrates. In cell lines, active gamma-secretase has been found to localize primarily to the Golgi apparatus, endosomes and plasma membranes. However, no thorough studies have been performed to show the subcellular localization of the active gamma-secretase in the affected organ of AD, namely the brain.Principal FindingsWe show by subcellular fractionation of rat brain that high gamma-secretase activity, as assessed by production of A beta 40, is present in an endosome-and plasma membrane-enriched fraction of an iodixanol gradient. We also prepared crude synaptic vesicles as well as synaptic membranes and both fractions showed high A beta 40 production and contained high amounts of the gamma-secretase components. Further purification of the synaptic vesicles verified the presence of the gamma-secretase components in these compartments. The localization of an active gamma-secretase in synapses and endosomes was confirmed in rat brain sections and neuronal cultures by using a biotinylated gamma-secretase inhibitor together with confocal microscopy.SignificanceThe information about the subcellular localization of gamma-secretase in brain is important for the understanding of the molecular mechanisms of AD. Furthermore, the identified fractions can be used as sources for highly active gamma-secretase.
|
|
| 5. |
- Hajduch, M, et al.
(författare)
-
An electrophoretic analysis of the seed protein body proteins from Pinus nigra
- 2001
-
Ingår i: Biologia plantarum. - 0006-3134 .- 1573-8264. ; 44:1, s. 137-140
-
Tidskriftsartikel (refereegranskat)abstract
- Protein bodies (PBs) of European black pine (Pirus nigra Am.) were isolated from mature seeds. Extracted soluble matrix proteins and crystalloid proteins PBs proteins were investigated by SDS-PAGE electrophoresis in presence and absence of 2-mercaptoethanol. The proteins of molecular masses 16, 17, 18, 61 and 65 kDa were presented only in crystalloid protein samples. Only 15 kDa protein was present in soluble matrix proteins and not in crystalloid proteins. Another protein bands were present in both soluble matrix and crystalloid proteins. 20, 37, 38, 39 and 48 kDa proteins were strongly visible among crystalloid proteins. Bands of 23 and 32 kDa were more visible in soluble matrix protein samples. Different composition in crystalloid proteins was found in absence of 2-mercaptoethanol: no proteins with molecular mass 71 kDa and more proteins in soluble matrix. In case of crystalloid proteins we detected 7 protein bands in interval from 71 to 212 kDa.
|
|
| 6. |
|
|
| 7. |
- Hrib, J, et al.
(författare)
-
Protein bodies in the pine megagametophyte in vitro culture : ultrastructural, histochemical and electrophoretic observations
- 2000
-
Ingår i: Biologia plantarum. - 0006-3134 .- 1573-8264. ; 43:3, s. 329-336
-
Tidskriftsartikel (refereegranskat)abstract
- The megagametophytes of the European black pine (Pinus nigra Am.) were cultured on modified MS medium. After 10 d, protein bodies showed well-marked degradation on freeze-etched replicas and in preparations observed by scanning electron microscopy. After 20 d of cultivation, the megagametophyte cells were completely empty. Proteins secreted into the agar medium were determined by electrophoresis and 15 different proteins, in the range of 6.5 to 71 kDa, were identified.
|
|
| 8. |
|
|
| 9. |
- Nahalka, J, et al.
(författare)
-
Elicitation of plumbagin by chitin and its release into the medium in Drosophyllum lusitanicum Link. suspension cultures
- 1998
-
Ingår i: Biotechnology letters. - 0141-5492 .- 1573-6776. ; 20:9, s. 841-845
-
Tidskriftsartikel (refereegranskat)abstract
- Polysaccharides (chitin/pectin) that are involved in the interactions between plants and microorganisms were applied to the cultured cells of Drosophyllum lusitanicum. In the case of chitin addition, elicitation and crystallization of plumbagin in the medium were observed. N-Acetylchitooligosaccharides smaller than heptamers [(GlcNAc)(n) (n<7)] elicited the biosynthesis of plumbagin but did not increase the hypersensitive response (HR). On the other hand, carboxymethylchitin (DP similar to 200) led to the accumulation of plumbagin in cells and to HR death as well as to the lysis of the cells and release of plumbagin into the medium. The response of cultured cells to the N-Acetylchitosaccharides varied depending on the chemo/physiological conditions of the cells. Addition of pectin (1 g/l) resulted in enhanced HR and decreased biosynthesis of plumbagin.
|
|
| 10. |
- Nahálková, Jarmila, et al.
(författare)
-
Affinity analysis of lectin interaction with immobilized C- and O-gylcosides studied by surface plasmon resonance assay
- 2002
-
Ingår i: Journal of Biochemical and Biophysical Methods. - 0165-022X .- 1872-857X. ; 52:1, s. 11-18
-
Tidskriftsartikel (refereegranskat)abstract
- A biosensor based on the surface plasmon resonance (SPR) principle was used for kinetic analysis of lectin interactions with different immobilized saccharide structures. A novel affinity ligands beta-D-glycopyranosylmethylamines derived from common D-aldohexoses linked to the carboxymethyl dextran layer of the SPR sensor surface served for interactions with a wide range of lectins. The method of preparation and use of the beta-D-mannopyranosyl glycosylated sensor surface was described. The results of affinity analysis of lectin-ligand interactions were evaluated and compared with data obtained from measurements using commercially available p-aminophenyl alpha-D-glycopyranosides. Possible applications and advantages of C- and O-glycosylated SPR biosensors are discussed.
|
|
