Chapleo S, Hall J L
The Biology Department, Building 44, The University, Southampton, SO9 5NH, UK.
New Phytol. 1989 Mar;111(3):369-379. doi: 10.1111/j.1469-8137.1989.tb00699.x.
Acid invertase (EC 3.2.1.26) is present in soluble and insoluble preparations from root and shoot tissue of Ricinus communis L. Greatest activity is found in expanding tissue, whilst very low activity is found in vascular and in Phloem-enriched tissue from stem internodes. In most tissues less than 20% of the total acid invertase activity is insoluble, the exception being extrafloral nectariess where 65-82% is insoluble. The activity of sucrose synthase (EC 2.4.1.13) is low in leaves and apical regions of the primary root; the root stele contains greater activity than the cortex. Considerable diel variations in leaf carbohydrate content were demonstrated and the results suggest that variations for the young sink leaves might be out of phase with those of source leaves by as much as one Photoperiod. The results are discussed m relation to the metabolism and transport of sucrose, particularly in roots.
酸性转化酶（EC 3.2.1.26）存在于蓖麻根和茎组织的可溶性及不溶性制剂中。在正在生长的组织中活性最高，而在茎节间的维管组织和富含韧皮部的组织中活性非常低。在大多数组织中，总酸性转化酶活性的不到20%是不溶性的，花外蜜腺除外，其中65 - 82%是不溶性的。蔗糖合酶（EC 2.4.1.13）的活性在叶片和初生根的顶端区域较低；根中柱的活性高于皮层。叶片碳水化合物含量呈现出明显的昼夜变化，结果表明幼嫩库叶的变化可能与源叶相差多达一个光周期。本文讨论了这些结果与蔗糖代谢和运输的关系，特别是在根中的情况。
