POLYAMINES IN NODULES FROM VARIOUS PLANT-MICROBE SYMBIOTIC ASSOCIATIONS

Polyamine compositions of root or stem nodules collected from varietie s of nitrogen-fixing leguminous (22 species) and non-leguminous (5 spe cies) plants were investigated. Relatively high concentrations of homo spermidine were observed in root or stem nodules of all the leguminous plants. Based on the ratio of homospermidine to spermidine, legume no dules were generally characterized into two major groupes; one contain ing almost equal amounts of homospermidine and spermidine, and the oth er a high homospermidine/spermidine ratio. Root nodules from pigeon pe a (Cajanus cajan L. Millsp) was the only exception which exhibited ver y low homospermidine/spermidine ratio. Amongst the legumes, nodules of adzuki bean (Vigna angularis), siratro (Macroptilium atropurpureum DC . Urb.), pea (Pisum sativum L.), and hairly vetch (Vicia hirsuta S.F. Gray) were rich in diamine putrescine. Such characters of nodule polya mine composition were inherent characteristics of each legume species, and not related to the type of infected rhizobia (Rhizobium or Bradyr hizobium). In contrast to herbaceous leguminous plants, nonleguminous woody plants, which symbiotically associate with actinomycete Frankia species, contained little polyamines in their root nodules. Root nodul es of non-leguminous Parasponia andersonii infected by bradyrhizobia w ere found to contain large quantities of putrescine and homospermidine . No significant differences in polyamine composition were observed be tween root and stem nodules both in Aeschynomene indica and Sesbania r ostrata.