Naturally occurring levels of putrescine, spermidine, and spermine were analyzed in female gametophyte (nonfertilized) and reproductive tissues (cystocarps) at two different stages of development in the marine red algae Gracilaria cornea J. Agardh. Endogenous polyamine levels changed at differential stages of cystocarp maturation. Highest polyamine values were found on tissue from the early post‐fertilization stage, decreasing as the cystocarp matured. Incubation experiments revealed that exogenous polyamines induced cystocarp maturation and promoted carpospore liberation, developing cell masses within 4 to 7 days in treatments with spermine. This is the first report on the effect of polyamines on cystocarp maturation in marine algae.

growth and morphogenesis and also increased the free and The levels of putrescine (Put), spermidine (Spd) and spermine bound PA levels in the sporelings. Tracer experiments using 70 (Spm) were analyzed in naturally collected samples of the marine macroalgae Dyctiota dichotoma, Gelidium canariensis kBq [U-14 C]-glycerol showed significant quantities of radioactivity in Put, Spd and Spm after 20 h of incubation. The effects and Grateloupia doryphora. Polyamines (PAs) appeared in free (35-134 mg g − 1 fresh weight) and bound TCA-insoluble of glycerol on growth were inhibited by the ornithine decarboxylase (EC 4.1.

The levels of putrescine (Put), spermidine (Spd) and spermine (Spm) were analyzed in naturally collected samples of the marine macroalgae Dyctiota dichotoma, Gelidium canariensis and Grateloupia doryphora. Polyamines (PAs) appeared in free (35–134 μg g−1 fresh weight) and bound TCA‐insoluble form (1 667–2 624 μg g−1 fresh weight). Axenic in vitro cultures of sporelings from G. doryphora were established in the medium containing glycerol. This medium promoted growth and morphogenesis and also increased the free and bound PA levels in the sporelings. Tracer experiments using 70 kBq [U‐14C]‐glycerol showed significant quantities of radioactivity in Put, Spd and Spm after 20 h of incubation. The effects of glycerol on growth were inhibited by the ornithine decarboxylase (EC 4.1.1.17) inhibitor α‐difluoromethylornithine (DFMO). The presence of DFMO in the incubation medium with [U‐14C]‐glycerol also reduced the radioactivity in PAs.

The levels of the polyamines putrescine, spermidine and spermine were analysed in different tissues of nature-collected samples of the seagrass Cymodocea nodosa. The highest accumulation of polyamines was found in the apical section of the rhizome. The putrescine/spermine ratio was highest in the senescent tissue of the leaf.

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