Behavior of organic acids and their importance on detoxication of aluminum in soils in forest ecosystem

森林生态系统土壤中有机酸的行为及其对铝解毒的重要性

• 批准号: 10660143
• 负责人: TAKENAKA Chisato
• 金额: $ 2.24万
• 依托单位: NAGOYA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10660143/
• 关键词: organic acid; Hinoki (Chamaecyparis obtusa); stemflow; Kunugi (Quercus serrata Thumb); rhizosphere; aluminum; detoxication; 樹木根

The purpose of this research is to clarify the role organic acids contained in stem flow and a secretion from tree root with respect to the detoxication of aluminum, which has various effects on plant growth.The data of pH, EC, TOC and ion balance in the stemflow of Hinoki (Chamaecyparis obtusa) show that those values of the initial stemflow were different from those of bulk samples and that the stemflow contains some organic anions. However, the results from the analysis of low molecular oorganic acid comfirmed that their contents in the stemflow were negligible. It was sugested that the organic anions contained in stemflow were various phenol substances originated from the bark constituents. The complexation abilityof organic substances in stemflow was evaluated by extraction experimentusing soils. As the results, no extra extraction of ions by using stemflow was observed. However, the possibility of complexation role of organic substancesin the stemflow was still expected because of the existence of various high molecular organic substances in the stemflow.The excretion of organic substances from roots of Kunugi (Quercus serrata Thumb) affected by aluminum was measured. The TOC concentration in the culture solution after Al treatments was lower that of control. The suppression of excretion of organic substance was not caused by deficiency of nutrients such as P or Ca but by direct Al effect. On the other hand, The tendency of the increase in the excretion of citric acid and malic acid was observed by Al addition. Therefore, it is concluded that Al in rhizospher causes the excretion of organic substances to both increase and decrease depending on the species.

本研究旨在阐明树干茎流和树根分泌物中所含的有机酸对铝毒害的解毒作用，铝对植物生长有多种影响。扁柏树干流中TOC和离子平衡的研究（Chamaaparis obtusa）的测定结果表明，初始茎流中的有机阴离子含量与大量样品中的有机阴离子含量不同，茎流中含有一定的有机阴离子。而低分子有机酸的分析结果表明，它们在茎流中的含量可以忽略不计。推测茎流中的有机阴离子是来源于树皮成分的各种酚类物质。采用土壤浸提实验研究了树干茎流中有机物的络合能力。作为结果，没有观察到通过使用茎流的额外的离子提取。但由于茎流中存在多种高分子有机物质，因此仍预计有机物质在茎流中具有络合作用的可能性。铝处理后培养液中TOC浓度低于对照。有机质排泄的抑制不是由于缺乏磷、钙等营养物质，而是由于铝的直接作用。另一方面，柠檬酸和苹果酸的排泄量随着铝的添加有增加的趋势。因此，可以得出结论，铝在根际引起的有机物质的排泄增加和减少取决于物种。

项目成果

Tomioka, R. and Takenaka C.: "Effect of aliminum stress on tree roots"Proceeding of International Symposium on oxidants/acidic species and forest decline in east Asia. (in press). (2000)

Tomioka, R. 和 Takenaka C.：“铝胁迫对树根的影响”东亚氧化剂/酸性物种和森林衰退国际研讨会论文集。

Tomioka, R. and Takenaka, C.: "Effects of aliminum stress on tree roots"Proceeding of International Symposium on Oxidants/acidic species and forest decline in east Asia. (印刷中). (2000)

Tomioka, R. 和 Takenaka, C.：“铝胁迫对树根的影响”东亚氧化剂/酸性物种和森林衰退国际研讨会论文集（2000 年出版）。

Tomioka,R.and Takenaka,C.: "Effects of aliminum stress on tree roots."Proceeding of International Symposium on Oxidants/acidic species and forest decline in east Asia. (印刷中). (2000)

Tomioka, R. 和 Takenaka, C.：“铝胁迫对树根的影响”。东亚氧化剂/酸性物种和森林衰退国际研讨会论文集（2000 年出版）。