冰川两种藓在超低温胁迫与恢复生长状态下叶肉细胞的超微结构

Ultrastructure of mesophyll cells of two species of mosses under ultra-low temperature stress and restored growth from glacier

为了探讨高寒冰缘区的藓类植物在超微水平的抗寒机制,该文对一号冰川下不同基质两种藓类植物水中土生的金黄银藓(Anomobryum auratum)和岩面土生的刺叶墙藓(Tortula desertorum)在常温、超低温胁迫和经胁迫后的恢复状态的超微结构进行对比。结果表明:室温下藓类植物叶肉细胞结构完整、清晰。-80℃超低温胁迫处理后叶肉细胞的超微结构的变化为两种藓类植物叶肉细胞大多数未出现质壁分离,但会出现质壁结构模糊,细胞质收缩;细胞器遭到破坏甚至解体的情况;淀粉粒、脂滴和液泡数量大大增加。在室温恢复过程中,线粒体数量增加,各个细胞器结构比超低温胁迫状态下完整性增加。根据该文的亚显微结构的分析推测这些变化是为了适应细胞迅速恢复生理功能,-80℃超低温胁迫没有完全使藓类植物丧失生理功能,还可以进行恢复。岩面土生刺叶蔷藓的叶细胞胞壁厚度为1100~1300 nm,大于水中土生金黄银藓的叶细胞胞壁厚度(200~700 nm),刺叶墙藓叶细胞胞壁比金黄银藓更厚,分析推断刺叶墙藓细胞器的抗胁迫能力也更强。综上结果表明:一号冰川的这两种藓类植物抗寒能力极强,它们独特的抗寒机制不仅与超微结构下植物淀粉粒、细胞器的结构和功能完整有关,还与其生境有关。

To study Anomobryum auratum in native water and Tortula desertorum in rocky face of two species of mosses in different substrates under the No.1 glacier.Ultrastructural comparison of desertorum at room temperature under ultra-low temperature stress and recovery after stress.The mechanism of cold resistance of the mosses in the alpine ice margin was observed at the ultra-low level.After ultrasonic cleaning with ultrasonic analyzer,it was divided into-80℃ultra-low temperature stress,room temperature recovery culture and normal temperature three groups,and ultra-thin sections were prepared by treatment with glutaraldehyde,phosphate buffer,citric acid,ethanol,acetone and other reagents.To observe and analyze the ultrastructure after dyeing.The results were as follows:The mesophyll of the mosses were intact and clear at room temperature.The ultrastructural changes of mesophyll cells under ultra-low temperature stress were as follows:Most of the mesophyll cells of the two mosses did not have plasmolysis,but the structure of the wall was blurred,the cytoplasm contracted;The organelles were destroyed or even disintegrated;The number of starch granules,lipid droplets and vacuoles were greatly increased.During the recovery at room temperature,the number of mitochondria increased,and each organelle structure was more complete than conditions of ultra-low temperature stress.According to the analysis of the ultrastructure in this paper,these changes are presumed to adapt to the rapid recovery of physiological functions of cells.The ultra-low temperature stress at-80℃does not completely lose the physiological function of the mosses,and those functions can also be restored.The thickness of mesophyll cell wall in the natural silver carp was 1100-1300 nm.The thickness of mesophyll cell wall in the rocky spurs was 200-700 nm.The cell wall of the rocky spurs wall was thicker than the natural silver carp.It is inferred that the resistance to stress of the thorn wall organelle is also stronger.These two species of mites have strong cold resistance,and their unique cold-resistance mechanism is not only related to the structure and function of plant starch granules and organelles under ultrastructure,but also related to their habitat.