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

点击翻译按钮获取中文摘要

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.