权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Function of polyamines in growth regulation of rhizobia in host and rhizosphere

多胺在宿主和根际根瘤菌生长调节中的作用

基本信息

批准号：
06660082
负责人：
OZAWA Takashi
金额：
$ 0.96万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

1.Soybean plants accumulated sufficient putrescine and spermidine in their nodules to inhibit the growth of Bradyrhizobium japonicum.2.Another substance that inhibits the growth of B.japonicum strains was isolated from soybean roots, and was identified as 4,7-dihydroxyisoflavone, daizein. The growth inhibition of bacteroids by daizein was depressed by spermidine.3.The following results suggest that H_2O_2 derived from the oxidative deamination of spermidine is responsible for the inhibitory effect of spermidine.1) Bacterois were sensitive to H_2O_2.2) The addition of catalase depressed the growth inhibition of spermidine.3) There was a correlation between the tolerances to H_2O_2 and spermidine in many B.japonicum strains.4) Spermidine resistant mutants of B.japonicum gained resistance to the inhibitory efrect of H_2O_2.4.The results in this study suggest that spermidine is concerned in the inhibition of nitrogen fixation activity of nodules by nitrate.5.Amine oxidase was purified from soybean seedling roots. This enzyme was classified into the type I amine oxidase. The experiments using this purified enzyme suggest that amine oxidase located on the surface of bacteroids catalyzes the oxidative deamination or polyamines, and the produced H_2O_2 cases the growth inhibition of bacteroids.6.Bacterial density in the homogenate of nodules did not decrease during the incubation of the homogenate, although there was enough amine oxidase and polyamines in the homogenate to inhibit the growth of bacteroids.The results obtained in this study suggest a mechanism regulating amine oxidase activity to control the density of bacteroids in the host plant.

1.大豆根瘤中积累的腐胺和亚精胺足以抑制慢生型大豆根瘤菌的生长。2.从大豆根中分离到另一种抑制慢生型大豆根瘤菌生长的物质，经鉴定为4，7-二羟基黄酮，即大豆黄素。3.亚精胺的抑制作用可能是由亚精胺氧化脱氨产生的H_2O_2引起的，1）拟杆菌对H_2O_2敏感，2）过氧化氢酶的加入可抑制亚精胺对拟杆菌的生长抑制作用，3）拟杆菌对H_2O_2的耐受性与亚精胺的耐受性有关4）抗亚精胺突变体获得了对H_2O_2抑制效应的抗性。4.本研究结果表明亚精胺与硝酸盐对根瘤固氮活性的抑制有关。这种酶被归类为I型胺氧化酶。用纯化的酶进行的实验表明，位于类杆菌表面的胺氧化酶催化氧化脱氨或多胺，产生的H_2O_2抑制类杆菌的生长。6.根瘤匀浆中的细菌密度在培养过程中没有降低，虽然匀浆中有足够的胺氧化酶和多胺抑制类菌体的生长，但本研究结果表明，调节胺氧化酶活性是控制类菌体生长的一种机制寄主植物中类杆菌的密度。