Tomas Bryngelsson - Academia.edu (original) (raw)

Papers by Tomas Bryngelsson

Physiol Molec Plant Pathol, 1989

... Alva) was grown for 10 days in a growth chamber at 20 C and a photoperiod of 16 h . The plant... more ... Alva) was grown for 10 days in a growth chamber at 20 C and a photoperiod of 16 h . The plants were inoculated with the mildew isolate MK 8110 (Erysiphe graminis Esp . ... 32 . WHITE, R . F ., RYBICKI, E . P., VON WECHMAR, M . B ., DECKER, JL ANTONIW, J. F . (1987) . ...

Plant Cell Reports, Mar 25, 2006

A double-gene construct with one chitinase and one β-1,3-glucanase gene from barley, both driven ... more A double-gene construct with one chitinase and one β-1,3-glucanase gene from barley, both driven by enhanced 35S promoters, was transformed into oilseed rape. From six primary transformants expressing both transgenes 10 doubled haploid lines were produced and studied for five generations. The number of inserted copies for both the genes was determined by Southern blotting and realtime PCR with full agreement between the two methods. When copy numbers were analysed in different generations, discrepancies were found, indicating that at least part of the inserted sequences were lost in one of the alleles of some doubled haploids. Chitinase and β-1,3-glucanase expression was analysed by Western blotting in all five doubled haploid generations. Despite that both the genes were present on the same T-DNA and directed by the same promoter their expression pattern between generations was different. The β-1,3-glucanase was expressed at high and stable levels in all generations, while the chitinase displayed lower expression that varied between generations. The transgenic plants did not show any major impact on fungal resistance when assayed in greenhouse, although purified β-1,3-glucanase and chitinase caused retardment of fungal growth in vitro.

Genetic Resources and Crop Evolution, 2015

Theoretical and Applied Genetics, 2012

Plant Systematics and Evolution, 2010

Parsimony-based phylogenetic analyses of the genus Guizotia were undertaken based on DNA sequence... more Parsimony-based phylogenetic analyses of the genus Guizotia were undertaken based on DNA sequence data from the following chloroplast DNA (cpDNA) regions: trnT-trnL, trnL-trnF, trnY-rpoB, trnC-petN, psbM-trnD and rps16-trnQ intergenic spacers, trnL, rps16 and matK-5 0 trnK introns and matK gene. Out of the 26 primers used in this study, 14 were newly designed. The study was conducted to determine (1) the closest relative of Guizotia abyssinica, (2) the taxonomic status of some Guizotia taxa and (3) the subtribal placement of Guizotia in the tribe Heliantheae. The analyses of the sequence data showed that G. abyssinica, G. scabra ssp. scabra, G. scabra ssp. schimperi and G. villosa are phylogenetically closely related. However, G. scabra ssp. schimperi appeared as the most closely related taxon to G. abyssinica. Based on this phylogenetic analysis, we suggest that the two subspecies of G. scabra are better treated as separate species. The analysis also clearly demonstrated that ''Chelelu'' and ''Ketcha'' are distinct Guizotia species. The trnT-trnL and trnL-trnF intergenic spacer-based phylogenetic analysis of various subtribes of the tribe Heliantheae strongly supports the placement of the genus Guizotia within the subtribe Milleriinae.

Plant Genetic Resources, 2008

Seventeen populations of niger (Guizotia abyssinica), representing all regions in Ethiopia where ... more Seventeen populations of niger (Guizotia abyssinica), representing all regions in Ethiopia where this crop is grown, were investigated using the amplified fragment length polymorphism (AFLP) technique, in order to determine the extent and distribution of its genetic diversity. A total of 539 AFLP loci were scored using seven primer combinations applied to 170 individual plants. Of these, 90% were polymorphic and all the individuals investigated were genetically unique. Despite the fact that most of the variation was within populations, populations were differentiated at a significant level (analysis of molecular variance;P < 0.001). There were no significant differences between populations in relation to the extent and altitude of cultivation. A significant positive correlation was revealed between Nei's standard genetic distance and geographic distance. Cluster analysis and principal coordinate analysis revealed that populations from the same regions were clustered together ...

Nucleic Acids Research, 1975

The level of deoxyadenylate (dA) regions in human DNA was estimated from formation of poly(U)-pol... more The level of deoxyadenylate (dA) regions in human DNA was estimated from formation of poly(U)-poly(dA) triplexes on nitrocellulose filters that were RNAase resistant. The (dA) rich sequences were determined following mild riXonuclease treatment of the poly(U)-DNA hybrids (5 pg/ml at 25 C for 20 min), where as exhaustive ribonuclease treatment (5 xg/ml at 25 C for 6 hr) estimated the more (dA) pure sequences. The level of (dA) rich regions was 0.39 % of the DNA and for the more (dA) pure regions it was 0.07 %. The (dA) regions were widely distributed throughout human DNA regardless of base composition or sequence repetition. However, a concentration of (dA) regions into main band CsCl gradient fractions of DNA and into repeated DNA was observed.

Molecular Immunology, 1996

Genetic Resources and Crop Evolution, 2007

Genetic diversity of 70 populations of niger (Guizotia abyssinica) representing all its growing r... more Genetic diversity of 70 populations of niger (Guizotia abyssinica) representing all its growing regions in Ethiopia was investigated using random amplified polymorphic DNA (RAPD) to reveal the extent of its populations genetic diversity. Ninety-seven percent of the loci studied was revealed to be polymorphic for the whole data set. The within population diversity estimated by Shannon diversity index and Nei gene diversity estimates was revealed to be 0.395 and 0.158, respectively. The extent of genetic variation of populations from major niger producing regions was significantly lower than that of populations from other regions; however, it is distributed regardless of altitude of growth. Genetic differentiation between populations was estimated with Shannon index as G 0 ST (0.432), Nei's G ST (0.242) and AMOVA based F ST (0.350) and appears to be equivalent to the average values calculated from various RAPD based studies on outcrossing species. Higher proportion of the variation detected by AM-OVA resided within populations (64.58%) relative to the amount of variation among populations (35.42%). UPGMA cluster analysis showed that most of the populations were clustered according to their region of origin. However, some populations were genetically distant from the majority and seem to have unique genetic properties. It is concluded that the crop has a wide genetic basis that may be used for the improvement of the species through conventional breeding and/or marker assisted selection. Collection of germplasm from areas not yet covered and/or underrepresented is the opportunity to broaden the genetic basis of genebank collection.

African Journal of …, 2011

… , molecular biology and …, 1992

Go to AGRIS search. Biochemical and molecular analyses of the response of barley to infection by ... more Go to AGRIS search. Biochemical and molecular analyses of the response of barley to infection by powdery mildew. ...

Genetic Resources and Crop Evolution, 2014

ABSTRACT Field pea (Pisum sativum L. subsp. sativum) is an important agricultural crop worldwide,... more ABSTRACT Field pea (Pisum sativum L. subsp. sativum) is an important agricultural crop worldwide, as a main source of protein in human diet and as animal fodder. In Ethiopia, it is the second most important legume crop next to faba bean (Vicia faba L.). However, the production is threatened by pea weevil (Bruchus pisorum L.), which is a rapidly spreading insect pest throughout the country. During June–October 2011, a total of 602 pea accessions from Ethiopia were screened for pea weevil resistance at three field sites in Ethiopia. From this trial, accessions with relatively low mean percent seed damage (PSD) were selected and evaluated during June-October 2012 in replicated trials. Some genotypes from the selected accessions were also studied under greenhouse conditions for up to three generations. Both in the field and greenhouse trials, a significant level of variation in PSD were observed among accessions/genotypes. However, a few of them showed relatively consistent results across sites and years. The gene bank accessions 32454 and 235002 had consistently <40 % PSD. These accessions had 17 and 33 % PSD, respectively, at a site where the highest and overall mean PSD were 92 and 75 %, respectively. Also, promising genotypes with consistently low levels of seed damage were identified in accessions 226037 and 32410. The incorporation of such promising accessions/genotypes into pea breeding programs may lead to the development of field pea varieties with enhanced resistance against pea weevil and consequently contribute to sustainable field pea production in Ethiopia and beyond.

Developments in Plant Pathology, 1993

ABSTRACT In Poaceae species, cold hardening (1°C for 2 wks), increases the freezing resistance of... more ABSTRACT In Poaceae species, cold hardening (1°C for 2 wks), increases the freezing resistance of the plants, and also increases the resistance to fungal diseases such as snow moulds, leaf spots, rusts and powdery mildews (Tronsmo 1984, and unpublished). In barley, resistance to powdery mildew may be induced by virulent and avirulent isolates of powdery mildew as well as by saprophytes (Bryngelsson and Collinge 1992 ). Are defence mechanisms induced by cold stress the same as those induced by biotic stress ?

Physiological and Molecular Plant Pathology, 1996

The perthotrophic fungus Drechslera teres, the causal agent of net blotch disease in barley, indu... more The perthotrophic fungus Drechslera teres, the causal agent of net blotch disease in barley, induces the accumulation of pathogenesis-related (PR) proteins in barley leaves as shown by isoelectric focusing. The same protein pattern was also found in leaves treated with a toxin extract from the culture filtrate of D. teres as well as after infection with Erysiphe graminis f.sp. hordei or Puccinia hordei. Some of the proteins induced by infection with D. teres were characterized as peroxidases, β-1,3glucanases and chitinases by isoenzyme analysis. Immunodetection following western blots demonstrated that the induced proteins are the same as those that accumulate after inoculation of barley with E. graminis : basic PR-1a and b proteins, thaumatin-like (TL) proteins, β-1,3glucanases and chitinases. The accumulation of PR-1 type proteins, chitinases and TL-proteins was analysed quantitatively by ELISA.

TheScientificWorldJournal, 2012

DNA sequence data from the internal transcribed spacer of nuclear ribosomal DNA and eight chlorop... more DNA sequence data from the internal transcribed spacer of nuclear ribosomal DNA and eight chloroplast DNA regions were used to investigate haplotypic variation and population genetic structure of the Afroalpine giant lobelia, Lobelia rhynchopetalum. The study was based on eight populations sampled from two mountain systems in Ethiopia. A total of 20 variable sites were obtained, which resulted in 13 unique haplotypes and an overall nucleotide diversity (ND) of 0.281 ± 0.15 and gene diversity (GD) of 0.85 ± 0.04. Analysis of molecular variance (AMOVA) revealed a highly significant variation (P < 0.001) among populations (F(ST)), and phylogenetic analysis revealed that populations from the two mountain systems formed their own distinct clade with >90% bootstrap support. Each population should be regarded as a significant unit for conservation of this species. The primers designed for this study can be applied to any Lobelia and other closely related species for population geneti...

Regulatory peptides, Jan 5, 1999

The ECL cells are peptide hormone-producing cells, rich in histamine and chromogranin A (CGA)-der... more The ECL cells are peptide hormone-producing cells, rich in histamine and chromogranin A (CGA)-derived peptides, that operate under the control of gastrin. Gastrin and the ECL cells form a functional unit, the gastrin-ECL-cell axis. The aims of the present study were to examine (1) if calcitonin (CT), parathyroid hormone (PTH) and vitamin D affect the gastrin-ECL-cell axis (by measuring the activity of the histamine-forming enzyme, histidine decarboxylase (HDC), and the expression of HDC mRNA and CGA mRNA in the ECL cells), and (2) if activation of the gastrin-ECL-cell axis affects the parathyroid glands (by measuring plasma PTH and mRNA expression). We also examined the possibility that the oxyntic mucosa harbours vitamin D receptors. Fasted rats received intravenous infusion of PTH and CT with or without gastrin. PTH raised the blood Ca2+ concentration, whereas CT infusion lowered it. Plasma PTH rose in response to CT, while serum gastrin remained unaffected. ECL-cell HDC was activ...

European Journal of Cancer (1965), 1978

European Journal of Cancer (1965), 1975

The levels of (dA) regions in 4 breast tumor DiVAs were compared with the level in normal DNA. Al... more The levels of (dA) regions in 4 breast tumor DiVAs were compared with the level in normal DNA. Although the (dA) regions in normal DNA remained constant in breast tissue, lymphocytes and placenta, (dA) alterations from the normal pattern were observed in the DNA from all four breast tumors. Tumor histology varied and was paralleUed by a corresponding variation in the (dA) alterations following a quantitative analysis of the (dA) rich and (dA) "pure" sequences. The (dA) alterations associated with 2 of the tumor DNAs were distributed into both A + T rich and G+C rich DNAfractions.

European Journal of Cancer (1965), 1976

The ( dA) levels in the D NAs from normal human tissues and from the lymphocytes of five CLL pati... more The ( dA) levels in the D NAs from normal human tissues and from the lymphocytes of five CLL patients were estimated by formation of ribonuclease A-resistant poly(U)-DNA co~Olexes. Alterations in the (dA) levels of all five CLL DiVAs were observed when comp~!rison was made to the normal ( dA) pattern. The type of ( dA) alterations varied among t~e different CLL patients, but the variation correlated to the WBC levels of the patients at the time of study. A specificity of neoplastic-associated (dA) alterations for slow repeated + unique DNA sequences and for main band DNA was demonstrated with two of the CLL DiVAs.