Studies on the water/nutrient delivery system and the control of root growth for growing vegetable crops in space.

研究太空蔬菜作物的水/养分输送系统和根系生长控制。

• 批准号: 05660022
• 负责人: TAKAHASHI Hideyuki
• 金额: $ 1.34万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05660022/
• 关键词: Space; Hydrotropism; Root; Water potential; Calcium; Water; nutrient delivery system; Cell wall; Gravity; 宇宙環境; 微小重力; 塊茎形成; 養水分供給システム; 重力反応; クリノスタット

To grow plants under microgravity conditions in space, it is necessary to develop a water/nutrient delivery system and to establish a method for the control of root growth, which solve problems caused by weightlessness environment. In the present study, we have studied the control mechanism of root hydrotropism and its relation to the gravitropic response, aiming at the use of root hydrotropism on the water/nutrient delivery system in space.On Earth, hydrotropism in roots is interfered by gravitropism, and the interaction between the two tropisms differ depending on plant species. This diversity of the responsiveness to gravity and moisture gradient was also confirmed in the roots of wheat plant. Simulation experiments suggested that normal gravitropic roots show strong hydrotropic response under a microgravity condition in space. We have developed a model system to establish moisture gradients for the study of hydrotropism. It was found that the root cap senses a moisture gradient of less than 1% RH mm^<-1> and a water potential gradient as small as 0.5 MPa mm^<-1>. The hydrotropic response, differential growth in the elongation zone, occurred following perception of water potential gradient by the root cap. The differential growth occurred due to a difference in cell wall extensibility between the dry side and the humid side of the tissue. It was also found that calcium was required for the induction of hydrotropism and that abscisic acid promoted the hydrotropism in roots. Some information that causes a difference in cell wall extensibility in the elongation zone may transmit from the root cap, and calcium and abscisic acid may be involved with the signal transduction or signal transmission mechanism. To screen and obtain plant species more suitable for the water/nutrient delivery system in space environment, we will clarify the genetic mechanism for hydrotropism in roots.

为了在空间微重力条件下种植植物，需要开发一种水/养分输送系统，并建立一种控制根系生长的方法，以解决失重环境引起的问题。在本研究中，我们研究了根向水性的控制机制及其与向重力反应的关系，旨在利用根的向水性在空间的水/养分输送系统。在地球上，根的向水性受到向重力性的干扰，这两种向性之间的相互作用取决于植物物种。小麦根系对重力和水分梯度的响应也存在差异。模拟实验表明，正常向重力性根系在空间微重力条件下表现出强烈的向水反应。我们已经开发了一个模型系统，以建立水分梯度的研究向水性。结果发现，根冠感测小于1%RH mm^的水分梯度<-1>和小至0.5MPa mm^的水势梯度<-1>。向水性反应，在伸长区的差异生长，发生以下感知水势梯度的根冠。由于组织的干侧和湿侧之间的细胞壁延展性的差异，发生了差异生长。钙是诱导向水性化所必需的，脱落酸促进了根的向水性化。引起伸长区细胞壁伸展性差异的某些信息可能是从根冠传递过来的，钙和脱落酸可能参与了信号传导或信号传递机制。为了筛选和获得更适合空间水分/养分输送系统的植物品种，我们将阐明根系向水性的遗传机制。

项目成果

Takahashi,H.: "Intensity of hydrostimulation for the induction of root hydrotropism and its sensing by the root cap." Plant,Cell and Environment. 16. 99-103 (1993)

Takahashi,H.：“诱导根向水性的水刺激强度及其通过根冠的感知。”

森田・阿部 編(分担執筆): "根のハンドブック" 根研究会, 232 (1994)

森田和安倍编（合着）：《根的手册》根研究组，232（1994）

Hirasawa,T.: "Control mechanism of differential growth in hydrotropism of pea roots." (発表予定).

Hirasawa, T.：“豌豆根向水性差异生长的控制机制”（待介绍）。

Takahashi, H.: "Hydrotropism and its interaction with gravitropism in roots." Plant and Soil. 165. 302-308 (1994)

Takahashi, H.：“向水性及其与根部向地性的相互作用。”

Takahashi,H.: "Gravitropic mutants in studying plant growth in space" Advances in Space Biology and Medicine. 4. 127-158 (1994)

Takahashi,H.：“研究太空植物生长的向重力突变体”太空生物学和医学进展。