Hellwege E M, Czapla S, Jahnke A, Willmitzer L, Heyer A G
Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Golm, Germany.
Proc Natl Acad Sci U S A. 2000 Jul 18;97(15):8699-704. doi: 10.1073/pnas.150043797.
The ability to synthesize high molecular weight inulin was transferred to potato plants via constitutive expression of the 1-SST (sucrose:sucrose 1-fructosyltransferase) and the 1-FFT (fructan: fructan 1-fructosyltransferase) genes of globe artichoke (Cynara scolymus). The fructan pattern of tubers from transgenic potato plants represents the full spectrum of inulin molecules present in artichoke roots as shown by high-performance anion exchange chromatography, as well as size exclusion chromatography. These results demonstrate in planta that the enzymes sucrose:sucrose 1-fructosyltransferase and fructan:fructan 1-fructosyltransferase are sufficient to synthesize inulin molecules of all chain lengths naturally occurring in a given plant species. Inulin made up 5% of the dry weight of transgenic tubers, and a low level of fructan production also was observed in fully expanded leaves. Although inulin accumulation did not influence the sucrose concentration in leaves or tubers, a reduction in starch content occurred in transgenic tubers, indicating that inulin synthesis did not increase the storage capacity of the tubers.
通过组成型表达菊芋（Cynara scolymus）的1-SST（蔗糖：蔗糖1-果糖基转移酶）和1-FFT（果聚糖：果聚糖1-果糖基转移酶）基因，将合成高分子量菊粉的能力转移到马铃薯植株中。如高效阴离子交换色谱以及尺寸排阻色谱所示，转基因马铃薯植株块茎的果聚糖模式代表了菊芋根中存在的菊粉分子的全谱。这些结果在植物体内证明，蔗糖：蔗糖1-果糖基转移酶和果聚糖：果聚糖1-果糖基转移酶足以合成特定植物物种中天然存在的所有链长的菊粉分子。菊粉占转基因块茎干重的5%，在完全展开的叶片中也观察到了低水平的果聚糖产生。虽然菊粉积累不影响叶片或块茎中的蔗糖浓度，但转基因块茎中的淀粉含量有所降低，这表明菊粉合成并未增加块茎的储存能力。
