研究证实,在地面上,植物细胞必须消耗能量来维持位置平衡对抗重力。在微重力条件下,这样的能量可以被保存用于其他过程,例如用于生长的有益代谢物的生物合成。在烟草细胞系(Nicotianatabacumcv。伯利21)。用2-Dclinostat连续处理细胞1周。暴露于倾斜旋转条件会增加生物量和总蛋白质。可溶性糖的总含量也增加,这可能为克雷布斯循环和三磷酸腺苷(ATP)生产提供更多的前体。在二维倾斜旋转的情况下,谷氨酸产生酶的表达和活性,谷氨酸脱氢酶(GDH)增加,而谷氨酸脱羧酶(GAD)的活性降低。关于GAD在启动γ-氨基丁酸(GABA)分流中的作用,在倾斜旋转条件下,烟草细胞将其新陈代谢导向为克雷布斯循环节省能量和更多的ATP生产,而不是转移到GABA分流等辅助路径。改善自由基清除酶的活性,增加酚类化合物和某些过氧化物中和氨基酸的含量,例如,他的,Pro,Ser,和Asp在倾斜条件下降低了膜脂过氧化并保持了烟草细胞的生长潜力。
Studies have confirmed that on the ground, the plant cells must expend energy to maintain positional homeostasis against gravity. Under microgravity conditions, such energy may be saved for other process such as biosynthesis of beneficial metabolites for growth. This hypothesis was examined on a cell line of tobacco (Nicotiana tabacum cv. Burley 21). The cells were continuously treated with 2-D clinostat for 1 week. Exposure to
clinorotation conditions increased biomass and total protein. Total content of soluble sugar also increased which may provide more precursors for Krebs cycle and adenosine triphosphate (ATP) production. In the case of 2-D
clinorotation, the expression and activity of glutamate producing enzyme, glutamate dehydrogenase (GDH) increased, whereas the activity of glutamate decarboxylase (GAD) decreased. Regarding the role of GAD in initiation of gamma amino butyric acid (GABA) shunt, it is plausible that under
clinorotation condition, the tobacco cells directed their metabolism toward saving energy for Krebs cycling and more production of ATP rather than shifting to side paths such as GABA shunt. Improvement of radical scavenging enzymes activity and increase of the contents of phenolic compounds and certain peroxide neutralizing amino acids, e.g., His, Pro, Ser, and Asp under
clinorotation conditions decreased membrane lipid peroxidation and maintained the growth potential of tobacco cells.