Control of leghaemoglobin synthesis in snake beans

Abstract

1. The finding that the plant is the genetic determinant of leghaemoglobin production in legume nodules was further tested by inoculating snake beans with two strains of Rhizobium selected to give large genetic differences. Carbohydrate requirement patterns, immunological techniques and DNA base ratio determinations were used to demonstrate genetic differences between the two rhizobial strains. 2. Partially purified preparations of the haemoglobins from the nodules produced by the two strains showed no differences when examined by electrophoresis, isoelectric focusing or ion-exchange chromatography. 3. Two different leghaemoglobins from each type of nodule were separated by chromatography on DEAE-cellulose. One of these was isolated in the Fe3+ form and accounted for two-thirds of the total leghaemoglobin. When it was examined in the analytical ultracentrifuge and by amino acid analysis, this major component did not vary with the inoculant rhizobial strain. The molecule had an s20,w of 1.88S, a diffusion coefficient of 10.7×10-7cm2·s-1 and a mol. wt. of 16700. 4. These results strongly support the hypothesis that the mRNA for leghaemoglobin is transcribed from plant DNA.

Ribosomal protein biomarkers provide root nodule bacterial identification by MALDI-TOF MS

“…Nodulation assays were carried out in Magenta jars containing vermiculite (Lewin et al 1987) with B&D nitrogen-free nutritive solution (Broughton and Dilworth 1971). Once surface-sterilized, seeds of C. cajan (pigeon pea) and Vigna unguiculata cv.…”

Ascorbate oxidase: The unexpected involvement of a ‘wasteful enzyme’ in the symbioses with nitrogen-fixing bacteria and arbuscular mycorrhizal fungi

“…Afterwards, seeds were again washed six times in sterile water and then placed onto sterile wet filter paper in a Petri dish. Seeds were germinated for at least 3 days at 16/8 h day/night cycle and 22 °C before being transferred onto squared Petri dishes containing ¼ B&D medium [36] for sterile cultivation or into pots containing quarz sand. Plants were grown for two weeks before being inoculated with M. loti.…”

The amino acid sequence of leghaemoglobin I from root nodules of broad bean (Vicia faba L.)

“…Gin Gl",Ala Le" Val:As";Ser Ser Se= Gl" le" Phe Lys of such polymorphisms are not apparently detected by ion-exchange chromatography, but may be the reason for the multiple bands seen when purified Lb preparations are subjected to isoelectric focussing electrophoresis in polyacrylamide gels [9]. That they occur in a Lb preparation which may contain material from 600 different plants is not surprising in view of the obvious scope for differences between even closely related plants such as soybean and kidney bean.…”