Morphological and histological differences among three types of component roots and their differential contribution to water uptake in the rice root system
Morphological and histological differences among three types of component roots and their differential contribution to water uptake in the rice root system
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DOI：
10.1080/1343943x.2020.1730701
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发表时间：
2020-02
影响因子：
2.5
通讯作者：
Yumika Watanabe;Takuya Kabuki;Takahiro Kakehashi;Mana Kano‐Nakata;Shiro Mitsuya;A. Yamauchi
中科院分区：
文献类型：
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作者：
Yumika Watanabe;Takuya Kabuki;Takahiro Kakehashi;Mana Kano‐Nakata;Shiro Mitsuya;A. Yamauchi
水稻根系由主根、L型侧根和S型侧根组成。这些组成根在形态和组织学上是不同的，这被称为heterorhizy。根系水力结构与组成根系的独特性有关。我们假设，每个组成根在不同程度上有助于整个根系的水分吸收。水稻品种IRAT 109和台中65在连续淹水（CWL）和干旱（CD）条件下在装满土壤的盆中生长，直到抽穗后两周。比较了三种组分根的形态和组织结构，它们可能调节水分的径向运动。此外，用压力室测定了根系的导水率（Lpr），它代表了根系的吸水能力。基于一个模型，整个根系的Lpr是Lpr的每个组成部分的根和它们的表面积的产品，我们发现，在两个品种之间的Lpr的差异和植物生长在不同的土壤水分条件下的任何组成部分的根不支持相应的差异，在整个根系的Lpr的测量。与此相反，整个根系的Lpr和S型LR的表面积的百分比之间的显着和正相关，但不为其他组成部分的根。这些结果表明，S型LR对整个根系Lpr的贡献可能高于其他组分根。图形摘要
ABSTRACT The rice root system consists of three types of roots; main root, L-type and S-type lateral root (LR). These component roots are morphologically and histologically different, which is termed as heterorhizy. Root system hydraulic architecture is related to the unique features of component roots. We hypothesized that each component root contributes in different degrees to water uptake of the whole root system. Rice varieties IRAT 109 and Taichung 65 were grown in pots filled with soil under continuous waterlogged (CWL) and drought (CD) conditions until two weeks after heading. Morphology and histological structures of roots, which may regulate radial water movement, were compared among the three component roots. Moreover, hydraulic conductivity (Lpr) of the root system, which represents the water uptake ability, were measured with a pressure chamber. Based on a model that Lpr of the whole root system is a product of Lpr of each of the component roots and their surface areas, we found that the differences in Lpr between the two varieties and the plants grown under different soil water conditions for any of the component roots did not support the corresponding differences in the measured Lpr of the whole root system. In contrast, a significant and positive correlation was found between Lpr of the whole root system and the percentage of surface area of S-type LR but not for the other component roots. These results indicate S-type LR might have a higher contribution to Lpr of the whole root system than the other component roots. Graphical Abstract