We have performed a seed-to-seed experiment in the cell biology experiment facility (CBEF) installed in the Kibo (Japanese Experiment Module) in the International Space Station. The CBEF has a 1 × g compartment on a centrifuge and a microgravity compartment, to investigate the effects of microgravity on the vegetative and reproductive growth of Arabidopsis thaliana (L.) Heynh. Seeds germinated irrespective of gravitational conditions after water supply on board. Thereafter, seedlings developed rosette leaves. The time of bolting was slightly earlier under microgravity than under space 1 × g. Microgravity enhanced the growth rate of peduncles as compared with space 1 × g or ground control. Plants developed flowers, siliques and seeds, completing their entire life cycle during 62-days cultivation. Although the flowering time was not significantly affected under microgravity, the number of flowers in a bolted plant significantly increased under microgravity as compared with space 1 × g or ground control. Microscopic analysis of reproductive organs revealed that the longitudinal length of anthers was significantly shorter under microgravity when compared with space 1 × g, while the length of pistils and filaments was not influenced by the gravitational conditions. Seed mass significantly increased under microgravity when compared with space 1 × g. In addition, seeds produced in space were found not to germinate on the ground. These results indicate that microgravity significantly influenced the reproductive development of Arabidopsis plants even though Earth's gravitational environment is not absolutely necessary for them to complete their life cycle.

中文翻译：

---

太空中微重力条件下拟南芥的营养和生殖生长。

我们已经在国际空间站Kibo（日本实验模块）中安装的细胞生物学实验设施（CBEF）中进行了种子到种子的实验。CBEF在离心机上有一个1 g的隔室，还有一个微重力隔室，用于研究微重力对拟南芥（L.）Heynh营养生长和生殖生长的影响。船上供水后，不论重力条件如何，种子都会发芽。此后，幼苗发育出莲座叶。在微重力作用下的锚固时间比在空间1×g下的锚固时间稍早。与空间1×g或地面对照相比，微重力提高了花序梗的生长速度。植物培育出花朵，长角果和种子，在62天的耕种过程中完成了整个生命周期。尽管在微重力作用下开花时间没有受到显着影响，但与空间1×g或地面对照相比，在微重力作用下，螺栓植物的花数显着增加。生殖器官的显微镜分析表明，与微距1×g相比，在微重力作用下，花药的纵向长度明显缩短，而雌蕊和细丝的长度不受重力条件的影响。与1×g的空间相比，在微重力作用下，种子质量显着增加。此外，发现在太空中产生的种子不会在地面上发芽。这些结果表明，微重力严重影响了拟南芥植物的生殖发育，即使地球