To elucidate a mechanism for enhancing mung bean seedlings’ growth under microgravity conditions, we measured growth, gene expression, and enzyme activity under clinorotation (20 rpm), and compared data obtained to those grown under normal gravity conditions (control). An increase in fresh weight, water content, and lengths were observed in the clinostat seedlings, compared to those of the control seedlings. Real-time PCR showed that aquaporin expression and the amylase gene were upregulated under clinorotation. Additionally, seedlings under clinorotation exhibited a significantly higher amylase activity. Near-infrared image showed that there was no restriction of water evaporation from the seedlings under clinorotation. Therefore, these results indicate that simulated microgravity could induce water uptake, resulting in enhanced amylase activity and seedling growth. Upregulated aquaporin expression could be the first trigger for enhanced growth under clinorotation. We speculated that the seedlings under clinorotation do not use energy against gravitational force and consumed surplus energy for enhanced growth.

为了阐明在微重力条件下促进绿豆幼苗生长的机制，我们测量了在回转 (20 rpm) 下的生长、基因表达和酶活性，并将获得的数据与在正常重力条件下生长的数据（对照）进行了比较。与对照幼苗相比，在 clinostat 幼苗中观察到鲜重、含水量和长度增加。实时 PCR 显示水通道蛋白表达和淀粉酶基因在斜向旋转下上调。此外，在单向旋转下的幼苗表现出显着更高的淀粉酶活性。近红外图像显示，在偏转下，幼苗的水分蒸发没有限制。因此，这些结果表明模拟微重力可以诱导吸水，导致增强的淀粉酶活性和幼苗生长。上调的水通道蛋白表达可能是在回转条件下促进生长的第一个触发因素。我们推测，斜旋下的幼苗不使用能量来对抗重力，而是消耗了多余的能量来促进生长。