Free-living soybean rhizobia and Bradyrhizobium spp. (lupine) have the ability to catabolize ethanol. Of the 30 strains of rhizobia examined, only the fast- and slow-growing soybean rhizobia and the slow-growing Bradyrhizobium sp. (lupine) were capable of using ethanol as a sole source of carbon and energy for growth. Two strains from each of the other Rhizobium species examined (R. meliloti, R...

We determined the sequences for a 260-base segment amplified by the polymerase chain reaction (corresponding to positions 44 to 337 in the Escherichia coli 16s rRNA sequence) from seven strains of fast-growing soybean-nodulating rhizobia (including the type strains of Rhizobium fredii chemovar fredii, Rhizobium fredii chemovar siensis, Sinorhizobium fredii, and Sinorhizobium xinjiangensis) and ...

Mineral oil, peanut oil and soybean oil were compared with water and gum arabic for their suitability as adhesives for seed inoculation with peat inoculants. Inoculated seeds were stored at 4, 28 and 34°C, and sampled after 1, 3 and 9 days to determine the survival of rhizobia. Germination and nodulation tests were performed on the inoculated seeds. Results showed that oils were suitable adhesi...

Why do rhizobia expend resources on fixing N(2) for the benefit of their host plant, when they could use those resources for their own reproduction? We present a series of theoretical models which counter the hypotheses that N(2) fixation is favoured because it (i) increases the exudation of useful resources to related rhizobia in the nearby soil, or (ii) increases plant growth and therefore th...

Lumichrome and riboflavin are novel molecules from rhizobial exudates that stimulate plant growth. Reported studies have revealed major developmental changes elicited by lumichrome at very low nanomolar concentrations (5 nM) in plants, which include early initiation of trifoliate leaves, expansion of unifoliate and trifoliate leaves, increased stem elongation and leaf area, and consequently gre...

Survival of Rhizobium trifolii on white clover seed before sowing is adversely affected by both drying and a water-soluble toxin which di f fuses f rom the seed coat dur ing the inocula t ion process . Survival of rhizobia is increased by removal of the toxin by seed washing or the suppress ion of i t s inhib i tory ef fec t by t rea tment of seed wi th phenol ic adsorbents . Surv iva l o f rh ...

Symbiotic root nodules arise from a well-coordinated interaction between leguminous plants and diazotropic soil bacterial collectively termed rhizobia. Legume roots release specific flavonoid compounds that are recognized by compatible rhizobia species. The rhizobia respond by producing lipochitooligosaccharide “nod factors” that are in turn recognized by LysM domain receptor-like kinases of co...

Despite the importance of mutualism as a key ecological process, its persistence in nature is difficult to explain since the existence of exploitative, "cheating" partners that could erode the interaction is common. By analogy with the proposed policing strategy stabilizing intraspecific cooperation, host sanctions against non-N(2) fixing, cheating symbionts have been proposed as a force stabil...

6-Phospho-D-gluconate:NAD+ 2-oxidoreductase (decarboxylating) (NAD+-6PGD) was detected in several slow-growing strains of rhizobia, and no activity involving NADP+ was found in the same extracts. By contrast, fast-growing strains of rhizobia had NADP+-6PGD activity; most of them also had NAD+-6PGD activity. NAD+-6PGD was partially purified from the slow-growing strain Rhizobium japonicum 5006. ...

Based on our previous study, cereal crop wheat (Triticum aestivum L.) could be infected by rhizobia Azorhizobium caulinodans ORS571, and form para-nodules with the induction of 2.4-dichlorophenoxyacetic acid, a common plant growth regulator. To enhance this infection and the potential agricultural application, we compared six different infection methods (Direct seed dip; Seed germination dip; P...