Sprouting of the fructan- and starch-storing geophyte Lachenalia minima:: Effects on carbohydrate and water content within the bulbs
Sprouting of the fructan- and starch-storing geophyte Lachenalia minima:: Effects on carbohydrate and water content within the bulbs
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DOI：
10.1034/j.1399-3054.2001.1130302.x
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发表时间：
2001-11-01
影响因子：
6.4
通讯作者：
Orthen, B
中科院分区：
文献类型：
--
作者：
Orthen, B
Lachenalia minima W.F. 球茎内的碳水化合物库Barker（风信子科）含有相似量的果聚糖和淀粉。这项研究的目的是检查田间条件下发芽过程中非结构碳水化合物库中发生的变化。球根被浇水 23 天，以模拟雨季的到来。尽管总果聚糖含量没有显着变化，但球茎不同叶鳞内果聚糖组分的分布和组成在发芽过程中发生了变化。主要变化发生在最内层鳞片，总果聚糖含量从300（第0天）增加到607（第23天）g kg(-1)干质量，高效阴离子交换色谱分析显示低聚合度（DP）果聚糖显着增加。就淀粉而言，伴随生长转变的最显着差异也在最里面的鳞片中。与果聚糖相反，淀粉含量从241（第0天）减少到60（第14天）g kg(-1)干质量。这些结果表明，淀粉而不是果聚糖被用作发芽的碳和能源。含水量数据表明果聚糖参与水关系。低DP果聚糖和蔗糖在最内部鳞片内的优先积累将水流引导至生长最需要的地方。干燥土壤中的球茎也发生了类似的变化，但转化速度要慢得多，而且发生的程度也较小，表明这些反应不是被触发的，而是被水加速了。
The carbohydrate pool within the bulbs of Lachenalia minima W.F. Barker (Hyacinthaceae) consists of similar amounts of fructans and starch. This study was conducted to examine the changes within the pool of non-structural carbohydrates that occur during sprouting under field conditions. The bulbs were watered over a period of 23 days to simulate the onset of the rainy season. Even though there was no significant change of the total fructan content, the distribution and the composition of the fructan fraction within the different leaf scales of the bulbs altered during sprouting. The major changes occurred in the innermost scales, the total fructan content increased from 300 (day 0) to 607 (day 23) g kg(-1) dry mass and high-performance anion-exchange chromatography analysis revealed a significant increase of fructans with low degree of polymerization (DP). With respect to starch, the most pronounced difference accompanying the transition to growth was also in the innermost scales. In contrast to fructans, starch content decreased from 241 (day 0) to 60 (day 14) g kg(-1) dry mass. These results demonstrate that starch, and not fructan, is used as the carbon and energy source for sprouting. The water content data suggest the involvement of fructans in water relations. The preferential accumulation of low DP fructans and sucrose within the innermost scales directs the water flow to where it is most needed for growth. Similar changes were obtained for bulbs in the dry soil, but transformation rates were much slower and occurred to a lesser extent, indicating that these reactions were not triggered but were accelerated by water.