Esau K, Magyarosy A C
J Cell Sci. 1979 Aug;38:11-22. doi: 10.1242/jcs.38.1.11.
The compounds crystalloids formed in sieve element nuclei of Amsinckia douglasiana A. DC. (Boraginaceae) during differentiation of the cell become disaggregated during the nuclear breakdown characteristic of a maturing sieve element. The phenomenon occurs in both healthy and virus-infected plants. The crystalloid component termed cy, which is loosely aggregated, separates from the densely aggregated component termed cx and disperses. The cx component may become fragmented, or broken into large pieces, or remain intact after the cell matures. After their release from the nucleus both crystalloid components become spatially associated with the dispersed P-protein originating in the cytoplasm, but remain distinguishable from it. The component tubules of P-protein are hexagonal in transections and are somewhat wider than the 6-sided cy tubules. The cx tubules are much narrower than the P-protein or the cy tubules and have square transections. Both the P-protein and the products of disintegrated crystalloids accumulate at sieve plates in sieve elements subjected to sudden release of hydrostatic pressure by cutting the phloem. The question of categorizing the tubular components of the nuclear crystalloid of a sieve element with reference to the concept of P-protein is discussed.
在道格拉斯勿忘草（紫草科）筛管分子细胞核中，细胞分化过程中形成的化合物晶体在成熟筛管分子典型的核解体过程中会解体。这种现象在健康植株和病毒感染植株中均会发生。被称为cy的晶体成分松散聚集，与被称为cx的紧密聚集成分分离并分散。cx成分可能会破碎成碎片，或分成大块，或者在细胞成熟后保持完整。从细胞核释放后，两种晶体成分在空间上都与源自细胞质的分散P蛋白相关联，但仍与P蛋白有区别。P蛋白的组成微管在横切面上呈六边形，比六边的cy微管稍宽。cx微管比P蛋白或cy微管窄得多，横切面呈方形。通过切割韧皮部使筛管分子静水压力突然释放时，P蛋白和晶体解体产物都会在筛板处积累。文中讨论了根据P蛋白的概念对筛管分子核晶体的管状成分进行分类的问题。
