Invasive Galega officianalis (Goat’s rue) plants in Canada form an association with the symbiotic bacterium, Neorhizobium galegae, from Eurasia

Citation

Eden Bromfield, Sylvie Cloutier, Catherine Robidas and Stephen Darbyshire (2017)
Invasive Galega officianalis (Goat’s rue) plants in Canada form an association with the symbiotic bacterium, Neorhizobium galegae, from Eurasia. 14th Symposium on Bacterial Genetics and Ecology, Aberdeen, Scotland, 4-8 June 2017

Plain language summary

The toxic legume plant, Galega officinalis is native to the Caucasus. This legume represents a threat to grazing animals and its establishment in Canada may have resulted from ornamental planting. In its native range, a symbiotic association with the host specific bacterium, Neorhizobium galegae, is required for normal growth.
Our purpose was to determine the species and symbiotic variety (symbiovar) identity of the nitrogen fixing bacteria associated with invasive plants of G. officinalis established at five sites in Canada. Sequence analysis of four housekeeping (16S rRNA, atpD, glnII and recA) and two symbiotic (nodC and nifH) genes showed that 50 bacterial isolates from G. officinalis at the five Canadian sites were strains of N. galegae symbiovar officinalis originating from Eurasia.
Axenic plant tests with G. officinalis indicated that soils collected from four Canadian sites without a history of agriculture or presence of G. officinalis were deficient in symbiotic bacteria capable of eliciting nodules on this plant.
Collectively these data support our hypothesis of co-introduction of exotic plant host and symbiotic bacterium into Canada most likely through transport of seed and soil material.

Abstract

The toxic legume plant, Galega officinalis is native to the Caucasus. This legume represents a threat to grazing animals and its establishment in Canada may have resulted from ornamental planting. In its native range, a symbiotic association with the host specific bacterium, Neorhizobium galegae, is required for normal growth.
Our purpose was to determine the species and symbiotic variety (symbiovar) identity of the nitrogen fixing bacteria associated with invasive plants of G. officinalis established at five sites in Canada. Sequence analysis of four housekeeping (16S rRNA, atpD, glnII and recA) and two symbiotic (nodC and nifH) genes showed that 50 bacterial isolates from G. officinalis at the five Canadian sites were strains of N. galegae symbiovar officinalis originating from Eurasia.
Axenic plant tests with G. officinalis indicated that soils collected from four Canadian sites without a history of agriculture or presence of G. officinalis were deficient in symbiotic bacteria capable of eliciting nodules on this plant.
Collectively these data support our hypothesis of co-introduction of exotic plant host and symbiotic bacterium into Canada most likely through transport of seed and soil material.

Publication date

2017-06-05