Analysis of the Bradyrhizobium nod gene-inducers from soybean super/hypernodulating mutants

抄録

In the soybean-Bradyrhizobium symbiosis, the initial stage of nodule formation is triggered by the release of the bacterial nod gene-inducing isoflavonoids from soybean plant. Analysis of the isoflavonoid contents in the seeds and root extracts of 12-day-old uninoculated soybean cultivars and their super/hypernodulating mutant using HPLC revealed that isoflavonoids daidzein, genistein, and coumestrol were present in the roots but only daidzein and genistein could be detected in the seeds. Moreover, all the super/hypernodulating soybean mutants showed lower isoflavonoid contents in the seeds and roots than their parent cultivars. These results suggest that in all the parent cultivars the genes which are probably responsible for controlling the isoflavonoid production are both affected during mutation despite the differences in the mutagen used and background of the seed materials.