PubMed Health⌕ Search

Biomedical subjects

T Bisseling

Publications and source records attributed to T Bisseling.

62 records · Page 4Linked to original sources

Development of the nitrogen-fixing and protein-synthesizing apparatus of bacteroids in pea root nodules.

Some aspects of root nodule development of Pisum sativum inoculated with Rhizobium leguminosarum were examined. 1. Nitrogenase activity (measured as acetylene reduction) appears to be preceded by leghemoglobin synthesis (measured immunologically). 2. Syntheses of component I and component II of nitrogenase are not strictly coordinated. Synthesis of component I starts before component II. 3. Plant and bacteroid protein synthesis (measured by [35S]sulfate labeling) in root nodules declines rapidly during nodule development. Corresponding with this decline is a decrease in quantity and quality of rRNA.

Fabaceae↗

The effect of ammonium nitrate on the synthesis of nitrogenase and the concentration of leghemoglobin in pea root nodules induced by Rhizobium leguminosarum.

The effects of NH4NO3 on the development of root nodules of Pisum sativum after infection with Rhizobium leguminosarum (strain PRE) and on the nitrogenase activity of the bacteroids in the nodule tissue were studied. The addition of NH4NO3 decreased the nitrogenase activity measured on intact nodules. This reduction of nitrogen fixation did not result from a reduced number of bacteroids or a decreased amount of bacteroid proteins per gram of nodule. The synthesis of nitrogenase, measured as the relative amount of incorporation of [35S]sulfate into the components I and II of nitrogenase was similarly not affected. The addition of NH4NO3 decreased the amount of leghemoglobin in the nodules and there was a quantitative correlation between the leghemoglobin content and the nitrogen-fixing capacity of the nodules. The conclusion is that the decrease of nitrogen-fixing capacity is caused by a decrease of the leghemoglobin content of the root nodules and not by repression of the nitrogenase synthesis.

Enzyme Precursors↗

RNA synthesis in puff 2-48BC after experimental induction in Drosophila hydei.

Puffs induced by treatment with vitamin B6 at locus 2-48BC in salivary gland cells of Drosophila hydei were isolated by micromanipulation, and the puff RNA was analyzed electrophoretically. The main RNA species migrated with a mobility of 40S. A similar RNA species was found in this puff after its induction by temperature treatment, except that in this case material with a higher mobility was also found, presumably due to the presence of growing chains. No evidence was found for polyadenylation of the RNA contained within the puff. The RNA profile of nucleoplasm of cells from glands either treated with vitamin B6 or subjected to a temperature shock also displayed a prominent peak with a mobility of 40S which was absent in extracts of nucleoplasm from control glands.

Animals↗

Prebiotic nucleotide synthesis-demonstration of a geologically plausible pathway.

Mineral phosphate (apatite) is activated for the synthesis of nucleotides when dilute solutions containing nucleoside and ammonium oxalate are evaporated in its presence. A natural, igneous fluorapatite was found to be even more effective in nucleotide synthesis than the more soluble hydroxylapatite. The phosphorylation is considerably more efficient if urea of cyanamide is also present. Hydrolysis of solutions of cyanogen to form oxalate and urea among other products is a spontaneous process that provides a geologically plausible model for necleotide synthesis on the primitive earth.

Apatites↗

The relationship between nodulin gene expression and the Rhizobium nod genes in Vicia sativa root nodule development.

The role of the Rhizobium nod genes in the induction of nodulin gene expression was examined by analyzing nodules formed on vetch roots by bacterial strains containing only the nod region. Introduction of an 11-kb cloned nod region of the R. leguminosarum sym plasmid pRL1JI into sym plasmid-cured rhizobia conferred on the recipient strains the ability to induce nodules in which all nodulin genes were expressed. This proves that from the sym plasmid only the nod region is involved in the induction of nodulin gene expression. A transconjugant of Agrobacterium carrying the same nod region induces nodules in which only early nodulin gene expression is detected. Thus, the nod region is essential for the induction of early nodulin gene expression. In this case, nodule cytology may indicate that a defense response of the plant interferes with the induction of late nodulin gene expression. Indirect evidence is presented that indeed the Rhizobium nod genes are also in some way involved in the induction of the expression of late noduling genes. The combination between histological data and pattern of nodulin gene expression furthermore reveals a correlation between nodule structure and nodulin gene expression. This correlation may aid in speculations about the functions of nodulins.

Blotting, Western↗

[Pea (Pisum sativum) genes participating in symbiosis with nitrogen-fixing bacteria. II. Nucleotide sequence of cDNA and parts of the late nodulin-6 (PsNod6) gene].

Certain characteristics of late noduline gene from pea-Nod6 were investigated as part of works of characterization of higher plant genes taking part in symbiotic nitrogen fixation. The complete 450 b.p. long cDNA was sequenced, it's coding sequence includes the open reading frame. The part of DNA containing the corresponding gene from the genomic clone was also sequenced. The predicted Nod6 amino acid sequence has been analyzed and do not reveal the significant homology with any known protein.

Amino Acid Sequence↗