Role of root hairs and lateral roots in silicon uptake by rice
Role of root hairs and lateral roots in silicon uptake by rice
复制标题
DOI：
10.1104/pp.010271
复制
发表时间：
2001-12-01
期刊：
影响因子：
7.4
通讯作者：
Ichii, M
中科院分区：
文献类型：
--
作者：
Ma, JF;Goto, S;Ichii, M
水稻（Oryza sativa L.）cv Oochikara）是一种硅积累植物，但其根系对硅的高吸收机制还不清楚。利用两个水稻突变体，一个是根毛形成缺陷型（RH 2），另一个是侧根形成缺陷型（RM 109），研究了根毛和侧根在水稻硅吸收中的作用。在短期（12 h）和相对长期（26 d）的营养液中的吸收实验表明，RH 2和野生型（WT）之间的Si吸收没有显著差异，而RM 109的Si吸收远低于WT。在淹水条件下，RH 2第3叶硅体形成数量与WT相近，而RM 109硅体形成数量仅为WT的40%。在高地土壤中生长时，WT和RH 2之间的地上部Si浓度也没有差异。使用多室运输箱，在根尖（0-1厘米，没有侧根和根毛）的硅吸收被发现是相似的WT，RH 2，和RM 109。但成熟区（距根尖1- 4cm）的硅吸收量RM 109显著低于WT，而WT与RH 2之间的硅吸收量差异不显著。这些结果表明，水稻侧根对硅的吸收有贡献，而根毛对硅的吸收无贡献。对RM 109和WT间的F-2群体的分析表明，硅吸收与侧根的存在相关，控制侧根形成和硅吸收的基因是显性基因。
The rice plant (Oryza sativa L. cv Oochikara) is known to be a Si accumulator, but the mechanism responsible for the high uptake of Si by the roots is not well understood. We investigated the role of root hairs and lateral roots in the Si uptake using two mutants of rice, one defective in the formation of root hairs (RH2) and another in that of lateral roots (RM109). Uptake experiments with nutrient solution during both a short term (up to 12 h) and relatively long term (26 d) showed that there was no significant difference in Si uptake between RH2 and the wild type (WT), whereas the Si uptake of RM109 was much less than that of WT. The number of silica bodies formed on the third leaf in RH2 was similar to that in WT, but the number of silica bodies in RM109 was only 40% of that in WT, when grown in soil amended with Si under flooded conditions. There was also no difference in the shoot Si concentration between WT and RH2 when grown in soil under upland conditions. Using a multi-compartment transport box, the Si uptake at the root tip (0-1 cm, without lateral roots and root hairs) was found to be similar in WT, RH2, and RM109. However, the Si uptake in the mature zone (1-4 cm from root tip) was significantly lower in RM109 than in WT, whereas no difference was found in Si uptake between WT and RH2. All these results clearly indicate that lateral roots contribute to the Si uptake in rice plant, whereas root hairs do not. Analysis of F-2 populations between RM109 and WT showed that Si uptake was correlated with the presence of lateral roots and that the gene controlling formation of lateral roots and Si uptake is a dominant gene.