Sterols and polyamines in IPT-transformed tobacco plants

Abstract

Free sterol and free polyamine contents were determined in the apex and the leaves of control and Pssu-ipt transformed tobacco (Nicotiana tabacum L. cv. Petit Havana SR1). The older leaves of ipt-transformed plants contained a much higher putrescine (put) content than those of control SR1 plants, whereas no significant differences for spermidine (spd) or spermine (spm) were found between control and ipt plants. Putrescine content corresponded well with endogenous cytokinin (free-bases) content and with ornithine- and ornithine-decarboxylose (ODC and ADC) activities. Plants transformed with ipt were characterized by a higher sterol content in the leaves and by a delay in the increase in the stigmasterol/sitosterol ratio that occurs from the upper to the lower leaves. Copyright (C) 1997 Elsevier Science Ltd.