水稻胚性悬浮细胞玻璃化冻存中的超微结构变化

Ultrastructural Changes in Rice Embryogenic Suspension Cells Cryopreserved by Vitrification

用透射电镜技术研究了水稻胚性悬浮细胞玻璃化冻存过程中细胞超微结构的变化规律。预培养降低了细胞的液泡化程度，线粒体嵴变得更为发达。过渡处理后，该细胞器开始膨大，其基质变得稀薄。脱水处理引起核周隙扩张和膜性物质小泡化。冷冻这一环节基本上不产生新的损伤。恢复生长时，水稻细胞重新获得正常的超微结构。预培养中的超微结构变化是抗冻力和抗脱水力提高的标志；过渡、脱水和冷冻中的超微结构变化是可逆损伤。讨论了上述变化的可能机制。

Ultrastructural changes in rice embryogenic suspension cells cryopreserved by vitrification were assessed using transmission electron microscopy. Preculture decreased the degree of vacuolation and the cristae mitochondriale became well developed. Swelling of mitochondria together with reduced matrix density were observed inthe loaded cells. After dehydration, expansion of nucleus cisternal space and vesiculation of membranous materialswere examined. No significant alterations occurred subsequently in the cooling step. During recovery culture, ricecells regained the normal ultrastructure. Molphological alterations during preculture step may be used as markers .ofimproved desiccation and freeze tolerance. Morphological alterations during loading, dehydration and cooling stepwere reversible injuries. The possible mechanisms for those results were discussed.