豌豆根瘤发育中侵染细胞核的超微结构变化

Nuclear Ultrastructural Changes of Infected Cell during the Development of Pea Root Nodules

用透射电镜研究了豌豆根瘤发育中侵染细胞核的超微结构变化。早期发育的侵染细胞核较大 ,近似圆形或椭圆形 ,核膜开始内陷。随着细胞的发育 ,细胞核变小 ,形状趋向扁平 ,核膜内陷增加 ,逐渐出现浓的染色质。在细胞衰老后 ,细胞核再度减小 ,核膜内陷加剧 ,浓的染色质增多。在早期的解体细胞中 ,虽然细胞质、细胞器和类菌体已经消失 ,但细胞核仍然清晰可见 ,只是浓的染色质进一步增多 ,常常位于核膜附近和核膜上。还讨论了侵染细胞核超微结构的特征和对细胞衰老的稳定性。

The nuclear ultrastructural changes of infected cell were studied by using transmission electron microscopy (during) the development of pea root nodules. We found that the features of nucleus in morphology were changed a lot during the development of infected cells. At the early phase of infected cell development, the nuclei were larger and approximated round-shaped or ellipse-shaped, a number of invagination appeared on nuclear envelopes. With cell development, the nuclei became smaller and flat-shaped. At the same time, invagination on nuclear envelopes was increased and the condensed chromatin in the nuclei gradually appeared. In cell senescence, the nuclei progressively became small and more invagination on their envelopes, the condensed chromatin was also increased in infected cells. In disintegrated cells, although their cytoplasm, organelles and bacteroids were lost, there still was an intact nucleus with a clear nuclear envelope and perinuclear space. However, the condensed chromatin was further increased and often located near by and on nuclear envelopes. The features of nuclear ultrastructure in infected cells and nucleus stability during infected cell senescence were discussed also.