Isolation of nodulation genes of leguminous plants by trasposon tagging

我们进行了以下实验。1)转座子标记我们尝试将Ac和Ds诱导到冠状荷花和苜蓿中。我们获得了一株Ds诱导植株，但没有获得Ac诱导植株。对于棘球蚴，我们无法确定适宜的Ac和Ds诱导条件。然后，我们尝试用粒子枪法和直接电穿孔法将Ds和Ac引入到龙螺中。2)杉科部分成员的结瘤。该科的成员通常在田间不结瘤。然而，一些成员如Chamaecrista命名为结节状。揭示结瘤和非结瘤植物之间的差异，将为创造固氮作物提供有用的信息。我们比较了在自然环境中未结瘤的樟子叶和樟子叶。不结瘤的物种显然从它们的种子和根分泌更多的类黄酮化合物。结果表明，在液体培养基中培养的番泻叶形成结节状结构。通过对番泻根分泌的黄酮类化合物的分析，试图阐明细菌接种是否诱导了一些特殊的黄酮类化合物。从本实验中可以看出，结瘤植株中黄酮类成分的变化明显，而非结瘤植株中黄酮类成分的变化不明显。根瘤菌产生的结瘤因子是根瘤形成的触发分子。我们开发了一种高效的这种分子的化学合成方法。

We carried out the following experiments.1) Transposon taggingWe tried to induce Ac and Ds into Lotus coroniculatus and Medicago trancatula. For L.cononiculatus we got one Ds induced plant, but did not get Ac induced one. For M.trancatula we could not determine suitable condition of Ac and Ds induction. Then, we are trying to introduce Ds and Ac into L.cononiculatus by the particle gun-method and direct electroporation-method.2) Nodulation of some members of family Caesalpineae.The members of family Caesalpineae usually are not nodulated in the field. However, some members such as Chamaecrista nomame are nodulated. To reveal the differences between nodulated and not-nodulated species will give useful information to create nitrogen fixing crops. We compared Chamaecrita nomame and Senna obtusifolia, which in not nodulated in the natural environments. Not-nodulating species apparently secreted much more flavonoid-like compounds from their seeds and roots. We found that Senna obtusifolia formed nodule-like structure when it was cultivated in the liquid medium. We analyzed flavonoid compositions secreted from roots of Senna obtusifolia and tried to clarify wheather bacterial inoculation induces some special flavonoids. From this experiment, the flavonoid composition was apparently changed in the nodulating plant but not in the not-nodulating plant.3) Chemical synthesis of nod factorNod factor produced by rhizobia is a trigger molecule of nodulation. We developed a highly efficient chemical synthesis method of this molecule.