A fundamental study on the new technique for production of Al-tolerant plants.

本研究旨在阐明铝毒和耐铝机理，为耐铝植物的生产提供基础资料。研究结果如下：1.铝毒和耐铝机理（1）植物对铝的吸收和转运特性因种而异，铝主要沉积在根尖、根的外部和细胞壁中，而与植物的耐铝性差异无关。(2)Al通过代谢抑制剂或在厌氧条件下大量扩散到根细胞中。维持根系质膜的排铝能力是植物耐铝的主要途径。(3)pH根系的上行能力或植物对低养分的耐受性不是耐铝性的原因。（4）铝离子形态对植物的毒性大小顺序为羟基铝聚合体离子>单体铝离子> AlSCr^+。根原生质体质膜表面负性与耐铝性的关系。（1）切片中根细胞的质膜被碱性染料高度染色，即，对铝敏感的植物中的亚甲蓝（用多功能图形分析仪测定）。（2）耐铝植物根原生质体亚甲基蓝染色值低，Zeta电位高。(3)Al各种碱性染料聚集原生质体并破坏质膜。（4）根由耐铝范围内的原生质体组成。耐铝植物的根由大量的耐铝原生质体组成.耐铝原生质体的分离与培养（1）利用耐铝原生质体的质膜负性，有可能发展从原始原生质体群体中分离耐铝原生质体的新技术。证明了番茄原生质体的培养条件。

The objectives of the present study are to clarify the mechanisms of Al-toxicity and Al tolerance and to offer fundamental information for the production of Al-tolerant plants. Results are summarized as follows.1. Mechanisms of Al toxicity and Al tolerance(1)Characteristics of Al uptake and translocation differ among plant species, and do not correlate with the differential Al tolerance among plant species.Al is highly deposited in the tip and the outer portions of roots, and in the cell wall. (2)Al considerably diffuses into root cells by metabolic inhibitors or in anaerobic conditions. Metabolically maintained Al excluding power of root plasmalemma is main strategy for Al tolerance.(3)pH ascending power of roots or the tolerances of the low nutrients in plants are not the cause of Al tolerance. (4)Phytotoxicity of Al ion species is in the order of hydroxy-Al polymer ions > monomeric Al ions > AlSCr^+_.2. Relationship between Al tolerance and the surface negativity of plasmalemma of root protoplasts.(1)Plasmalemma of root cells in the section is stained highly with basic dyes,i.e., methylene blue, in Al-sensitive plant species (measuring with multi-purpose graphic analyzer). (2)Methylene blue stainability of root protoplasts is low and zeta potential of them is high in Al-tolerant plant species. (3)Al and various basic dyes aggregate protoplasts and destroy the plasmalemma. (4)Root is composed of protoplasts of a range of Al tolerances. Root of Al-toleraht plant is composed of a large number of Al-tolerant protoplasts.3. Separation and culturing of Al-tolerant protoplasts(1)New technique for the separation of Al-tolerant protoplasts from original protplast population may be able to be developed by utilizing the plasmalemma negativity of Al-tolerant protoplasts. Conditions for culturing of tomato protoplasts are certified.