Esau K, Magyarosy A C
J Cell Sci. 1979 Aug;38:1-10. doi: 10.1242/jcs.38.1.1.
The presence of usually single, elongated, compound crystalloids in nuclei of sieve elements is an outstanding characteristic of the phloem of Amsinckia douglasiana A. DC. (Boraginaceae). The crystalloid consists of two components forming alternating panels, or blocks, that extend through the entire length of the crystalloid and radiate from the centre where one of the components predominates. Three to seven panels for each component were recorded. One component consists of 4-sided tubules closely packed in highly ordered aggregates, the other of wider 6-sided tubules rather loosely arranged in paracrystalline aggregates. The crystalloid arises at the beginning of sieve element differentiation. Aggregates of 4-sided tubules appear first. In plants infected with the curly top virus, the crystalloids do not differ from those in non-infected controls in structure and conformation. But because the phloem in infected plants is hyperplastic, with most of the cells differentiating as sieve elements, the crystalloids are far more abundant in diseased than in healthy plants.
在道格拉斯琴颈草（Amsinckia douglasiana A. DC.，紫草科）韧皮部中，筛管分子细胞核内通常存在单个、细长的复合晶体，这是其突出特征。该晶体由两个组分构成，形成交替的板层或块体，贯穿晶体全长，并从其中一个组分占主导的中心向外辐射。每个组分记录到三至七个板层。一个组分由紧密排列成高度有序聚集体的四边形小管组成，另一个组分由排列较为松散的平行晶体聚集体中的较宽六边形小管组成。晶体在筛管分子分化开始时出现。四边形小管的聚集体首先出现。在感染卷叶病毒的植物中，晶体在结构和构象上与未感染对照植物中的晶体并无差异。但由于感染植物的韧皮部增生，大多数细胞分化为筛管分子，所以患病植物中的晶体比健康植物中的丰富得多。
