Response of rice (Oryza sativa) with root surface iron plaque under aluminium stress
Response of rice (Oryza sativa) with root surface iron plaque under aluminium stress
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DOI：
10.1093/aob/mcl110
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发表时间：
2006-08-01
期刊：
影响因子：
4.2
通讯作者：
Ma, Jian Feng
中科院分区：
文献类型：
--
作者：
Chen, Rong Fu;Shen, Ren Fang;Ma, Jian Feng
水稻（Oryza sativa）是一种水生植物，其根表具有形成铁膜的特性。它被认为是谷类作物中最耐铝的物种。研究了水稻根表铁膜对铝转运、积累的影响以及铝胁迫下水稻生理反应的变化。9方法以粳稻品种越光为材料，在生长箱中进行水培试验。将水稻根暴露于30 mg L-1亚铁（Fe（II）-EDTA营养液中6 d，方法I）或FeSO 4水溶液中12 h，诱导铁膜形成。根分泌物中的有机酸被保留在阴离子交换树脂中，用2 M HCl洗脱，然后经适当的预处理后用高效液相色谱（HPLC）分析。结果与结论两种方法（Ⅰ和Ⅱ）均能诱导水稻根表铁膜的形成。DCB可提取的铁和铝的根表面上的量要高得多，在铁菌斑的存在下比在没有铁菌斑。铁膜处理显著降低了根尖Al含量，显著降低了AT从根向地上部的转运。铝诱导的柠檬酸盐分泌，铁菌斑可以大大抑制柠檬酸盐的分泌。这些结果表明，水稻根表铁膜可以作为铝的固定库，铁离子可以使根尖铝结合位点预饱和，从而在一定程度上保护根尖免受铝胁迫的伤害。
Background and Aims Rice (Oryza sativa) is an aquatic plant with a characteristic of forming iron plaque on its root surfaces. It is considered to be the most Al-tolerant species among the cereal crops. The objective of this study was to determine the effects of root surface iron plaque on Al translocation, accumulation and the change of physiological responses under Al stress in rice in the presence of iron plaque. 9Methods The japonica variety rice, Koshihikari, was used in this study and was grown hydroponically in a growth chamber. Iron plaque was induced by exposing the rice roots to 30 mg L-1 ferrous iron either as Fe(II)-EDTA in nutrient solution (6 d, Method I) or as FeSO4 in water solution (12 h, Method II). Organic acid in root exudates was retained in the anion-exchange resin and eluted with 2M HCl, then analysed by high-performance liquid chromatography (HPLC) after proper pre-treatment. Fe and Al in iron plaque were extracted with DCB (dithionite-citrate-bicarbonate) solution.Key Results and Conclusions Both methods (I and II) could induce the formation of iron plaque on rice root surfaces. The amounts of DCB-extractable Fe and Al on root surfaces were much higher in the presence of iron plaque than in the absence of iron plaque. Al contents in root tips were significantly decreased with iron plaque; translocation of At from roots to shoots was significantly reduced with iron plaque. Al-induced secretion of citrate was observed and iron plaque could greatly depress this citrate secretion. These results suggested that iron plaque on rice root surfaces can be a sink to sequester Al onto the root surfaces and Fe ions can pre-saturate Al-binding sites in root tips, which protects the rice root tips from suffering Al stress to a certain extent.