Study on effects of pseudo-microgravity (PMG) environment to soybean root growth and symbiosis for R/D of space agriculture

在本项目中，比较了大豆在三维回转器产生的拟微重力(PMG)环境下的植株形态变化，并与地面种植的对照样品进行了比较。结果表明，种植PMG的大豆根长、侧根数和根细胞的增殖活性均有所增加。这些观察结果与arf8和pgp1的基因表达密切相关。此外，PMG生长的样品的根瘤原基数量也有所增加。为了开发一种通过电容检测来现场测量根伸长的方法，需要两个电极；一个连接到茎上，另一个插入土壤中。在干土和湿土中成功地测得了电容值随根伸长深度的变化。

In this project, changes of plant morphology of Soybean under pseudo-microgravity (PMG) environment produced by a 3-D clinostat were compared with ground-grown control samples. As a result, root length, number of lateral root and proliferation activity of root cells for PMG-grown soybean were increased. These observation were close relationship to gene expressions between arf8 and pgp1. Furthermore, the number of root nodule primordium on PMG-grown sample was increased. To develop an in-situ method for measuring root elongation by capacitance detection, two electrodes; one of them is attached to the stem and the other is inserted in to the soil. The capacitance which changes with depth of root elongation was successfully detected in dry soil and wet soil.