Druart N, De Roover J, Van den Ende W, Goupil P, Van Laere A, Rambour S
Laboratoire de Physiologie et Génétique Moléculaire Végétales, Université des Sciences et Technologies de Lille, France.
Planta. 2001 Feb;212(3):436-43. doi: 10.1007/s004250000414.
The activities of enzymes of both sucrose and fructan metabolism were measured in chicory (Cichorium intybus L. cv. Turbo) plants during early vegetative growth. From 21 to 42 d after sowing (phase I), carbohydrates were used for structural growth and sucrose was predominantly cleaved by acid invertase whereas neutral invertase (EC 3.2.1.26) and sucrose synthase (EC 2.4.1.13) activities were low. From 49 to 63 d after sowing (phase II) a cambium formed producing secondary tissues, concomitant with induced sucrose:sucrose 1-fructosyl transferase (1-SST; EC 2.4.1.99) and fructan:fructan-1-fructosyl transferase (EC 2.4.1.100) activities, and fructan synthesis in the roots. Accumulation of 1-SST mRNA occurred at the onset of thickening, indicating that 1-SST is controlled at a transcriptional level. Acid invertase activity gradually increased during phase I and remained high during early phase II. It subsequently decreased. The pattern of invertase mRNA accumulation correlated with the enzyme activities, indicating that acid invertase is controlled at the transcriptional level. Both acid invertase and 1-SST probably contributed to the sink strength in the root at the beginning of phase II.
在菊苣（菊苣品种Turbo）植株营养生长早期，对蔗糖和果聚糖代谢相关酶的活性进行了测定。播种后21至42天（阶段I），碳水化合物用于结构生长，蔗糖主要由酸性转化酶裂解，而中性转化酶（EC 3.2.1.26）和蔗糖合酶（EC 2.4.1.13）的活性较低。播种后49至63天（阶段II），形成了产生次生组织的形成层，同时诱导了蔗糖：蔗糖1-果糖基转移酶（1-SST；EC 2.4.1.99）和果聚糖：果聚糖-1-果糖基转移酶（EC 2.4.1.100）的活性，以及根中的果聚糖合成。1-SST mRNA在增厚开始时积累，表明1-SST在转录水平受到调控。酸性转化酶活性在阶段I逐渐增加，并在阶段II早期保持较高水平。随后其活性下降。转化酶mRNA积累模式与酶活性相关，表明酸性转化酶在转录水平受到调控。在阶段II开始时，酸性转化酶和1-SST可能都对根中的库强有贡献。
