Host Influence on the Ultrastructure of Root Nodules of Lupinus luteus and Ornithopus Sativus

Abstract

SUMRlARYThe ultrastructure of Lupinus luteus L. and Ornithopus sativus Brot. root nodules derived from infection by Rhizobium lupini strain ~2 5 was examined. In both cases the associations produced completely effective nodules but their gross morphology was markedly different. Bacteria within the 0. sativus nodules were enclosed in groups by a membranous envelope, and the bacteria had electron translucent regions. Bacteria within the L. luteus nodules were enclosed singly and did not exhibit similar electron translucent regions. Starch granules were observed within infected cells of L. luteus but not within uninfected cells; the reverse was observed in 0. sativus cells.

Invertase and Disulphide Bridges in the Yeast Wall

“…It is conceivable that retention of extracellular enzymes by an impermeable wall is not peculiar to yeasts; the evidence that wall permeability is involved in Neurospora was mentioned earlier. Bacterial walls also offer similar possibilities since wall permeability (Mitchell, 1959 ;Gerhardt & Judge, 1964) appears to be limiting for particles of protein size. The release of surface enzymes from bacteria (Heppel, 1967;Neu & Chou, 1967;Rogers, 1968) may reflect wall impermeability.…”

“…Electron microscopy. Material for sectioning was fixed according to the Glauert & Thornley (I 966) modification of the Ryter-Kellenberger technique and embedded in Epon (Kidby & Goodchild, 1966), except that prefixation with glutaraldehyde was omitted for half of the material sampled. This omission appeared to yield a better definition of intracellular detail but this distinction was not critically examined.…”

Nucleic Acid Changes in Bacteroids of Rhizobium lupini During Nodule Development

“…The morphology of the lupin nodule has been discussed by Kidby & Goodchild (1966). Because only a collar of nodule tissue is formed from the initial inoculation, it is possible to obtain material of uniform age and development.…”

Inhibition of Protein Synthesis by D-threo-chloramphenicol in the Laboratory and Nodule Forms of Rhizobium lupini

“…If permeability differences do exist then they are likely to be important in the maintenance of the legumerhizo bium symbiosis. In situ, bacteroids (or small groups of bacteroids) are surrounded by a plant membrane within the cytoplasm of the central nodule tissue (Dart & Mercer, 1963;Jordan et al 1963;Kidby & Goodchild, 1966). The success of the rhizobium is therefore dependent on the interactions between the two symbiotic partners, with the host cell providing the environment in which the bacterial form can change to the N,-fixing form.…”