Su Jin-Wei, Wang Xiang-Ping
Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Zhi Wu Sheng Li Yu Fen Zi Sheng Wu Xue Xue Bao. 2005 Apr;31(2):190-8.
The ultrastructural changes of meristematic cell during the degeneration of gynoecium primordium leading to the formation of staminate flower of litchi were followed. Degradation of the cells and transport of the dissolved cytoplasmic components were well ordered. Configurations of rough endoplasmic reticulum (RER) changed significantly. ER played an important role in degenerative processes of gynoecium primordiuml cells. The degenerative processes started with the appearance of long RER cisternae throughout the cytoplasm. Some long RER cut or enclosed the cytoplasm. Some RER connected nucleus and mitochondria of adjacent cells, formed a ridge-like connection. Later the RER formed concentric patterns and then became irregular stacks. RER and golgiosome produced many vesicles, which were importance to protoplasmic degradation and intercellular transport of the cellular debris. The number of mitochondria increased up to the time when they began to degrade in batches. Peroxisomes appeared temporarily at the middle stage near the nucleus. The nucleolus disintegrated at the beginning of degeneration of nucleus. Then fragments of chromatin aggregated at the periphery of nuclear membrane and diffused outward. In some nuclei the perinuclear membrane became dilated and puffs were formed. As cell degeneration progressed, the protoplasm disintegrated and dissipated in an orderly fashion, i.e. ribosomes became disorganized first, followed by peroxisomes, ER, golgiosoms, mitochondria and nucleus. Eventually, gynoecium primordium cells digested all of the cytoplasm, leaving only cell wall with high electron density. Most of the products of degeneration of gynoecium primordium cells were removed through either symplastic or apoplastic pathways. Programmed cell death (PCD) may be involved in the degeneration of meristematic cells at the gynoecium primodium.
对荔枝雌蕊原基退化形成雄花过程中分生组织细胞的超微结构变化进行了跟踪观察。细胞的降解以及溶解的细胞质成分的转运过程井然有序。粗面内质网（RER）的形态发生了显著变化。内质网在雌蕊原基细胞的退化过程中发挥了重要作用。退化过程始于细胞质中出现长的内质网池。一些长的内质网切割或包围细胞质。一些内质网连接相邻细胞的细胞核和线粒体，形成脊状连接。随后内质网形成同心模式，然后变成不规则的堆叠。内质网和高尔基体产生许多小泡，这对原生质降解和细胞碎片的细胞间转运很重要。线粒体数量增加，直至开始分批降解。过氧化物酶体在中期暂时出现在细胞核附近。核仁在细胞核退化开始时解体。然后染色质片段聚集在核膜周边并向外扩散。在一些细胞核中，核周膜扩张并形成泡状。随着细胞退化的进展，原生质以有序的方式解体和消散，即核糖体首先解体，接着是过氧化物酶体、内质网、高尔基体、线粒体和细胞核。最终，雌蕊原基细胞消化了所有细胞质，只留下具有高电子密度的细胞壁。雌蕊原基细胞的大部分退化产物通过共质体或质外体途径被清除。程序性细胞死亡（PCD）可能参与了雌蕊原基分生组织细胞的退化。
