回转器模拟微重力对拟南芥生物特性的影响

Effects of Simulated Microgravity with Clinostat on Biological Characteristics of Arabidopsis thaliana

目的研究模拟微重力条件对拟南芥生长过程中生理、生化特性以及亚显微结构的影响。方法通过回转仪模拟微重力环境,利用激光共聚焦扫描显微镜和Ca2+荧光探针对生长7 d的拟南芥幼苗进行细胞微管骨架变化、Ca2+分布以及相关酶活力进行研究测定。结果在模拟微重力条件下拟南芥植株生长慢于对照;拟南芥叶片细胞的微管骨架有序性降低,微管数量显著增加,其排列模式呈现多样化,叶绿体含量有所减少;根尖Ca2+分布趋向均匀化,并且Ca2+向叶片组织的转运增加;过氧化物酶、过氧化氢酶活力以及抗坏血酸含量显著增加,超氧化物歧化酶活力有所增加,匀浆蛋白含量有所减少。结论模拟微重力环境对拟南芥的生物特性有显著影响,拟南芥幼苗应激反应明显。

Objective To study the effects of simulated microgravity on physiological and biochemmal charac- teristics and cell submicroscopic structure of Arabidopsis thaliana. Methods Clinostat was used to simulate the microgravity environment. The changes in microtubules of the leaf cells, Ca2 ＋ distribution and enzyme activi- ties of Arabidopsis thaliana that had grown for 7 days in the simulated microgravity conditions were investigated with Laser scanning confocal microscope and Fluo-3/AM. Results The plant grew slower and much smaller under the simulated microgravity condition as compared with the control. Microtubule skeleton of the leaf cells became scattered and disordered, the number of microtubules increased significantly, the arrange mode be- came diversified, and the number of chloroplasts reduced; Ca2＋ in root tip cells distributed evenly and had a trend of transferring to the leaf tissue cells of Arabidopsis thaliana ; The activities of POD, CAT, Vc and SOD were increased while the homogenate protein concentration was decreased under simulated microgravity condi- tion. Conclusion Biological characteristics of the Arabidopsis thaliana are affected profoundly by the simulated microgravity condition and the stress response of the seedling is obvious.