Polyamines in Nodules from Various Plant-Microbe Symbiotic Associations

Polyamine compositions of root or stem nodules collected fromvarieties of nitrogen-fixing leguminous (22 species) and non-leguminous(5 species) plants were investigated. Relatively high concentrationsof homospermidine were observed in root or stem nodules of allthe leguminous plants. Based on the ratio of homospermidineto spermidine, legume nodules were generally characterized intotwo major groupes; one containing almost equal amounts of homospermidineand spermidine, and the other a high homospermidine/spermidineratio. Root nodules from pigeon pea (Cajanus cajan L. Millsp)was the only exception which exhibited very low homospermidine/spermidineratio. Amongst the legumes, nodules of adzuki bean (Vigna angularis),siratro (Macroptilium atropurpureum DC. Urb.), pea (Pisum sativumL.), and hairly vetch (Vicia hirsuta S.F. Gray) were rich indiamine putrescine. Such characters of nodule polyamine compositionwere inherent characteristics of each legume species, and notrelated to the type of infected rhizobia (Rhizobium or Bradyrhizobium).In contrast to herbaceous leguminous plants, nonleguminous woodyplants, which symbiotically associate with actinomycete Frankiaspecies, contained little polyamines in their root nodules.Root nodules of non-leguminous Parasponia andersonii infectedby bradyrhizobia were found to contain large quantities of putrescineand homospermidine. No significant differences in polyaminecomposition were observed between root and stem nodules bothin Aeschynomene indica and Sesbania rostrata. (Received June 13, 1994; Accepted August 17, 1994)