Elucidation of the systemic mechanism which controls root nodule formation in soy bean plants

1.控制大豆超结突变体根瘤形成的叶源材料的筛选以大豆超结突变体NOD 1 -3的第一片三叶为材料，进行了大豆超结突变体根瘤形成的叶源材料筛选。从大豆品种（cv.将Williams 82或NOD 1 -3连续导入插穗叶片中，并评价其控制生根的活性。结果表明：1）Williams 82叶片提取物中含有抑制NOD 1 -3扦插苗超枝的目标物质，该物质具有半极性和分子量小于10^4的特点。2）在HPLC分析中，上述物质被检测为两个不同的峰。在Williams 82扦插中没有发现诱导超结的物质，目前HPLC中两个峰不同的物质正在提纯中，不久将进行鉴定.通过Williams 82特异的茎衍生材料寻找NOD 1 -3根基因当不仅Williams 82而且日本大豆栽培品种的野生型接穗嫁接到NOD 1 -3的砧木上时，嫁接植物不显示超结性状。因此，使用嫁接了Williams 82和NOD 1 -3的接穗的NOD 1 - 3砧木的根，通过mRNA消减法，检索了野生型大豆中特异性产生的芽来源材料所靶向的NOD 1 -3根基因，结果可知，通过获得Williams 82接穗，在NOD 1 -3砧木根中存在新表达的基因和表达停止的基因。

1. Search of the leaf derived materials which control root nodule formation of a supernodulation mutant of soybeanA soy bean rooting cuttage made from the first triplet leaf of a supernodulation mutant, NOD1-3, was used for screening target materials. Leaf extract or its fraction prepared from soybean cv. Williams82 or NOD1-3 was continuously introduced into the leaflet blades of the cuttage and evaluated its activity of controlling root nodulation. As a result, the next points became clear.1) Target material restraining supernodulation of the NOD1-3 cuttage is contained in the leaf extract of Williams82, and it shows trait of semipolarity and low molecular weight of less than 10^4.2) The material mentioned above is detected as two different peaks in HPLC analysis.3) In leaf extract of NOD1-3, there was no material inducing supernodulation in Williams82 cuttage.Now, the materials caught by HPLC as different two peaks are under refinement, and we are going to identify near future.2. Search of NOD1-3 root genes to be targeted by the shoot derived materials specific to Williams82When the wild type scion of not only Williams82 but also Japanese soybean cultivars is grafted onto a stock of NOD1-3, the graft plant does not show supernodulation trait. Therefore, NOD1-3 root genes to be targeted by the shoot derived materials produced specifically in the wild type soybean were searched by a mRNA subtraction method using roots of NOD1-3 stocks onto which scions of Williams82 and NOD1-3 were grafted.As a result, it became clear that there are both genes newly expressed and stopped to be expressed in NOD1-3 stock roots by getting Williams82 scion.