Bultynck L, Geuns J M, Van Ginkel G, Caubergs R J
Ruca, Antwerp, Belgium.
Phytochemistry. 1997 Aug;45(7):1337-41. doi: 10.1016/s0031-9422(97)00171-4.
Application of 10 successive daily heat shocks reduced the growth of control tobacco (Nicotiana tabacum L. cv. Petit Havana SR1) plants by about 15%; for Phsp 70-ipt transformed plants this is about 48%. The shoot diameter of these ipt-transformed plants increased by about 75%. In addition, in heat shock treated ipt-plants (IPT-HS) the upper lateral buds grew out due to a reduction of apical dominance. The older leaves of IPT-HS plants had a higher chlorophyll content. In spite of the observed effects due to a higher endogenous cytokinin content in the IPT-HS plants, no significant changes were observed on the plasma membrane fatty acid composition, nor on its fluidity as determined from the steady-state fluorescence anisotropy of DPH. Only a minor change in the plasma membrane free sterol composition was found as evidenced by a 20% decrease in the stigmasterol to sitosterol ratio in IPT-HS, indicative for a possible anti-senescence effect of enhanced endogenous cytokinins, but without significant effects on the plasma membrane function.
连续10天每日进行热激处理，使对照烟草（烟草品种 Petit Havana SR1）植株的生长降低了约15%；对于转Phsp 70-ipt基因的植株，生长降低约48%。这些转ipt基因植株的茎直径增加了约75%。此外，在热激处理的ipt植株（IPT-HS）中，由于顶端优势减弱，上部侧芽生长出来。IPT-HS植株的老叶叶绿素含量更高。尽管观察到IPT-HS植株中由于内源性细胞分裂素含量较高而产生了一些效应，但在质膜脂肪酸组成及其流动性方面未观察到显著变化，质膜流动性是通过DPH的稳态荧光各向异性测定的。仅发现质膜游离甾醇组成有微小变化，IPT-HS中豆甾醇与谷甾醇的比例降低了20%，这表明内源性细胞分裂素增强可能具有抗衰老作用，但对质膜功能无显著影响。
