PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “root development”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources
PubMed1973

Changes in certain aminoacyl transfer ribonucleic Acid synthetase activities in developing pea roots.

Tyrosyl-, arginyl-, leucyl-, and phenylalanyl-tRNA synthetase activities were measured in extracts from three root sections of 3-day-old pea seedlings. The sections 0 to 2, 3 to 7, and 8 to 22 millimeters from the root tip were chosen to represent the regions of cell division, elongation, and maturation, respectively. The specific activity for each aminoacyl-tRNA synthetase was highest in the 0- to 2-millimeter section and lowest in the 8 to 22 millimeter section. The changes in specific activity between the sections, however, varied with the particular synthetase. Tyrosyl-tRNA synthetase from each section was fractionated into two activity regions on a diethylaminoethyl cellulose column. Approximately 10, 22, and 44% of the total tyrosyl-tRNA synthetase activity in the 0 to 2, 3 to 7, and 8- to 22-millimeter sections, respectively, were associated with the first tyrosyl-tRNA synthetase region; the remaining activity was located in the second tyrosyl-tRNA synthetase region. Only one activity region for arginyl-tRNA synthetase was detected by diethylaminoethyl cellulose column fractionation.

Journal Article↗
PubMed1980

Electrophoretic comparison of polypeptides from enriched plasma membrane fractions from developing soybean roots.

The polypeptide complement of enriched soybean (Glycine max [L.] Merr. cult. wells) root plasma membrane fractions was studied by two-dimensional gel electrophoresis. Good resolution was obtained when polypeptides were solubilized in sodium dodecyl sulfate and when butylated hydroxytoluene was included in the vesicle isolation and solubilization media. The pattern obtained on the two-dimensional slab gel for root plasma membrane was characteristic for that membrane. The polypeptide complements from mitochondrial membranes and from enriched fractions of three other endomembrane components were solubilized and electrophoresed for comparison. Each membrane preparation was identifiable on the basis of its characteristic electrophoretogram. Electrophoresis of protein solubilized from plasma membrane fractions isolated from meristematic and mature root tissue revealed both qualitative and quantitative differences in the respective protein complements.

Journal Article↗
PubMed1987

Effects of Rhizobium meliloti nif and fix mutants on alfalfa root nodule development.

Ineffective alfalfa nodules were examined at the light and electron microscope level after inoculation with Rhizobium meliloti strains with mutations in nif and fix genes. All the mutant strains induced nodules that contained elongated bacteroids within the host cells, but the bacteroids quickly senesced. The nodules were small and numerous, and the host cells also exhibited symptoms of an ineffective symbiosis. nifB, fixA, and fixB bacteroids appeared to be completely differentiated (by ultrastructural criteria), i.e., as bacteroids developed, they increased in diameter and length and their cytoplasm underwent a change from homogeneous and electron dense to heterogeneous and electron transparent after enlargement. In contrast, nifA bacteroids rarely matured to this state. The bacteroids degenerated at an earlier stage of development and did not become electron transparent.

Medicago sativa↗
PubMed1980

Changes in the outer cell wall of Rhizobium during development of root nodule symbiosis in soybean.

Treatment of soybean root nodule tissue with a nonionic detergent. Nonidet P-40, after aldehyde fixation, results in a selective solubilization of membranes. The cell wall membrane of bacteroids and of free-living Rhizobium is resistant to this treatment. Fragments of "extra" membrane present inside the membrane envelope enclosing the bacteroids are also resistant to the detergent and are morphologically similar to the outer membrane of the cell wall of Rhizobium grown in broth culture. These observations, along with electrophoretic profiles of detergent resistant membranes from nodules, free-living Rhizobium, and isolated nodule bacteroids, suggest that the Rhizobium cell wall membrane undergoes significant changes during establishment of the root nodule symbiosis.

Cell Membrane↗
PubMed2007

Hidden branches: developments in root system architecture.

The root system is fundamentally important for plant growth and survival because of its role in water and nutrient uptake. Therefore, plants rely on modulation of root system architecture (RSA) to respond to a changing soil environment. Although RSA is a highly plastic trait and varies both between and among species, the basic root system morphology and its plasticity are controlled by inherent genetic factors. These mediate the modification of RSA, mostly at the level of root branching, in response to a suite of biotic and abiotic factors. Recent progress in the understanding of the molecular basis of these responses suggests that they largely feed through hormone homeostasis and signaling pathways. Novel factors implicated in the regulation of RSA in response to the myriad endogenous and exogenous signals are also increasingly isolated through alternative approaches such as quantitative trait locus analysis.

Adaptation, Physiological↗
PubMed1987

Lupin leghemoglobins during root nodule development.

Two yellow lupin leghemoglobins, Lb I and Lb II, were purified to homogeneity using the HPLC technique for final separation. Lb I and Lb II were identified by the N-terminal sequences and their reaction with antibodies against electrophoretically pure leghemoglobin. The third Lb species was detected by the combined method of isoelectrofocusing and PAGE of Lb I. It seems that Lb III represents a posttranslational modification of Lb I. Developmental changes in Lb multiple forms were examined using the Western blotting method. The content of leghemoglobin, first detectable approximately 3 weeks after infection, increased up to 6-7 weeks, and then it remained at the same level until 8-9 weeks after the infection. At the early stages of nodule formation Lb I prevailed over Lb II, while later Lb II became the predominant form. This suggests physiological role of particular forms and precise regulation of the expression of Lb genes.

Amino Acid Sequence↗
PubMedDate not supplied

[Medical informatics: historical roots and development since the 60's].

From the start, the development of the industrialized countries required observations in order to get informations on the demographic, administrative and health situation. In the course of centuries, methods of collecting and evaluating data improved. On the other hand, there was a stepwise development of auxiliary technical devices which allow to keep proven components and compose them with new ones under higher angles. Individual pioneers contributed to develop computers of high calculating capacity. The semi-conductor technique, its ongoing improvement and use in microelectronic industry gave rise to a revolution of information engineering. There was a tremendous development since the early sixties with an expanded use of computers in medicine. In a first phase, they helped overtaking auxiliary functions in clinical administration and measuring equipment in laboratories. Then, patient oriented systems with large data bases were created. In recent years, electronic telecommunication connecting hospital information systems (e.g. in university hospitals), but also other information centres on a national and international level, is of growing importance. The development of information techniques with broadened fields of application--e.g. medical image processing, handling of linguistic problems--is a challenge for medicine. Medical thinking has to channel information techniques properly with the aim of getting useful results, conserving privacy and avoiding irrelevant decision making.

History, 15th Century↗