개구리자리 엽병 세포 신장에 대한 폴리아민의 효과를 조사하였다. 외부에서 폴리아민을 처리하면 옥신에 의한 세포신장이 크게 억제되는 반면, putrescine의 생합성 억제제인 α-difluoromethylarginine을 처리하면 옥신에 의한 신장이 증가한다. Spermine은 fusicoccin에 의한 신장도 역시 뚜렷이 억제하였으나 낮은 pH에 의하여 유도되는 생장에는 효과가 없었다. 또한 spermine을 처리하면 옥신이 있는 조건에서 에틸렌에 의한 신장촉진 효과가 사라진다는 결과를 얻었다. 컴퓨터에 연결된 video digitizer system을 이용하여 IAA에 의하여 유도되는 엽병 생장에 미치는 spermine 억제 키네틱스를 분석한 결과, spermine은 초기 신장률과 안정 신장률을 감소시켰으나 잠복기의 길이에는 효과를 미치지 않았다.

Possible roles of polyamines in the inhibition of cell elongation in Ranunculus petioles were investigated. Exogenously applied polyamines greatly inhibited the auxin-induced petiole growth, while treatment of the tissue with α-difluoromethylarginine, the inhibitor of putrescine biosynthesis, further enhanced the growth in the presence of IAA. Inhibitory effect of spermine can also be apparent for fusicoccin-induced elongation, but not for growth induced by a low pH. Spermine also suppressed the ethylene-enhanced growth in the presence of auxin. Using computer-based video digitizer system, the inhibitory effects of spermine on petiole growth were kinetically analyzed. Auxin-induced growth was characterized by an initial and transient growth with a highly elevated rate followed by a steady growth with a slightly reduced rate. Spermine treatment was found to shorten the duration of the initial phase of growth, and to reduce the rates of both the initial and steady growth as well. The latent period for auxin induction was not affected by spermine.