Aqueous silicate complexes in wheat, Triticum aestivum L.
Aqueous silicate complexes in wheat, Triticum aestivum L.
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DOI：
10.1046/j.0016-8025.2003.01124.x
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发表时间：
2004-01-01
影响因子：
7.3
通讯作者：
Epstein, E
中科院分区：
文献类型：
--
作者：
Casey, WH;Kinrade, SD;Epstein, E
小麦木质部分泌物中硅的化学形态研究通过Si-29 NMR光谱检查。使小麦植物在无硅营养培养基中生长至成熟，然后转移至含有0.02mM富含Si-29的油酸的溶液中。30分钟后，切除芽并收集木质部渗出物。在10分钟内，木质部渗出物的Si浓度达到大大超过起始营养液的Si浓度的值，最终达到高达8 mM的水平。Si-29核磁共振谱表明木质部渗出物中仅存在两种含Si物质，单和二硅酸（H4 SiO 40和（HO）（3）Si（μ-O）Si（OH）（3）（o）），比例约为7：1。值得注意的是，没有有机硅酸盐复合物的证据。然而，植物浓缩水溶性硅的效率表明硅穿过根细胞膜的运输的积极机制。
The chemical speciation of silicon in xylem exudate from wheat (Triticum aestivum L.) was examined by Si-29 NMR spectroscopy. Wheat plants were grown to maturity in silicon-free nutrient medium, and then transferred to a solution containing 0.02 mM Si-29-enriched silicic acid. After 30 min the shoots were excised and xylem exudate was collected. Within 10 min the Si concentration of the xylem exudate reached values greatly in excess of that of the starting nutrient solution, eventually reaching levels as high as 8 mM. Silicon-29 nuclear magnetic resonance spectra indicated the existence of only two Si-containing species in the xylem exudate, mono and disilicic acid (H4SiO4o and (HO)(3)Si(mu-O)Si(OH)(3)(o)) in a ratio of approximately 7 : 1. Significantly, there was no evidence of organosilicate complexes. Nevertheless, the efficiency by which the plant concentrates aqueous silicon indicates active mechanisms of silicon transport across root cell membranes.