A SECONDARY EFFECT OF TRANSFORMATION IN RHIZOBIUM-LEGUMINOSARUM TRANSGENIC FOR BACILLUS-THURINGIENSIS SUBSPECIES TENEBRIONIS DELTA-ENDOTOXIN (CRYIIIA) GENES

By introducing Bacillus thuringiensis subspecies tenebrionis delta-end otoxin genes (cryIIIA) into Rhizobium leguminosarum we have produced s trains for the biological control of Sitona larvae. Comparisons betwee n a transgenic and the parent: strain show that transformation has ind uced changes not associated with the intended function of the transgen e. Although growth rates in laboratory cultures are similar for both s trains, the ability to compete for nodule occupancy is greater in the transgenic than in the son-transformed parent strain. This result demo nstrates the importance of studying ecological and agronomic character s of transgenic micro-organisms that could have a bearing on the safet y and success of their release into the environment, even if they are not thought to be connected with the transgenes introduced.