Mechanisms on the Al tolerance and accumulation of plants adapted to low pH soils

低pH土壤植物对铝的耐受和积累机制

基本信息

批准号：
09460035
负责人：
OSAKI Mitsuru
金额：
$ 2.5万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09460035/
关键词：
Aluminum sensitive plants Aluminum excluder plants Aluminum require plants Al accumulator plants low pH adapted plants low pH tolerant plants Al感受性植物 Al排除植物 Al要求性 Al集積植物

项目摘要

The effects of N-source and Al on the growth of seedlings of Melastoma malabathricum, Acacia mangium and Melaleuca cajuputi, which are tropical woody plants and are very tolerant to Al, and barley (Hordeum vulgare), which is a typical Al-sensitive plant, were investigated. The Al and N treatments consisted of the application of either 0 or 0.5 mM Al, and 2 mM NH_4^+ or NO_3^-, respectively. Growth of the tropical plants was enhanced by Al and NH_4 application. Excised roots of M.malabathricum dissolved insoluble Al with NH_4 application and absorbed Al mainly from root tips. Al did not affect the leaf N concentration except in the case of barley. Roots of M.cajuputi exuded a large amount of citrate, which slightly increased by the +Al treatment. In A.mangium, the reactivity of soluble Al to PCV (pyrocatecholviolet) decreased in the culture solution of the +Al+NH_4 treatment and Al concentration of roots in this treatment was very low. Roots of M.malabathricum released H+ along with Al uptake as well as NH_4^+ uptake. It is concluded that Al and NH_4^+ exert beneficial effects on the growth of tropical tree seedlings.Al appeared mostly in apoplastic fraction in excised melastoma roots treated with 0.1 mM Al for 180 min, and CCCP did not affect the Al uptake, indicating that Al uptake in the excised roots occurs mostly through passive accumulation in the apoplast. The Al ion displaced 3H^+ on carboxyl groups in the melastoma root apoplast when it was taken up, a finding not observed in barley. This adsorption site had a higher affinity to the Al ion compared with Ca^<2+> or La^<3+>. On the other hand, three months after Al exposure, Al concentration in the symplastic and residual fractions of the melastoma roots was very high and surpassed that in the apoplastic fraction. From the results in the present and previous studies, a hypothesis of the Al uptake mechanism in melastoma roots was proposed.

N源和Al对Melastoma malabathricum，Acacia angacium和Melaleuca cajuputi的幼苗生长的影响，它们是热带木本植物，对Al非常耐受，而大麦（Hordeum vulgare）是典型的Al-Al-sens敏感的植物，研究了。 AL和N处理分别由0或0.5 mM Al的应用和2 mM NH_4^+或NO_3^ - 组成。 AL和NH_4的应用增强了热带植物的生长。 M.Malabathricum溶解的不溶性Al的根部通过NH_4施加，主要是从根尖吸收的。除大麦外，Al不影响叶子n浓度。 M.cajuputi的根散发了大量柠檬酸盐，通过 +Al治疗略有增加。在A.Mangium中，在 +Al +NH_4处理的培养溶液中，可溶性Al对PCV（pyocatecholviolet）的反应性降低，而在这种处理中，根的浓度非常低。 M.Malabathricum的根与Al摄取以及NH_4^+摄取一起释放了H+。结论是，Al和NH_4^+对热带树幼苗的生长产生了有益的影响。AL主要出现在用0.1 mM Al处理的切除的绿色绿色根中，持续180分钟，CCCP并没有影响Al的摄取，表明这表明这表明切除根中的Al摄取主要通过凋亡中的被动积累发生。静脉瘤根凋亡中的羧基上的Al离子在被吸收时偏移了3H^+，这一发现未在大麦中观察到。与ca^<2+>或la^<3+>相比，该吸附位点对Al离子具有更高的亲和力。另一方面，在Al暴露后三个月，梅拉斯瘤根的符号和残留部分的Al浓度非常高，并且在占主体分数中的浓度超过了。从目前和以前的研究的结果中，提出了梅拉斯瘤根中Al摄取机制的假设。