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。我们试图将Ac和D诱导到莲花和紫花苜蓿中。对于圆锥花，我们得到了一个DS诱导的植株，但没有得到一个Ac诱导的植株。对于横纹夜蛾，我们不能确定Ac和DS诱导的适宜条件。然后，我们尝试用基因枪法和直接电穿孔法将DS和Ac导入圆锥花。2)对凯撒松亚科的一些成员进行结瘤。然而，一些成员，如Chamaecrista Nomame是节点化的。揭示节生和非节生物种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节的雪莲和番泻叶。非结瘤物种显然从它们的种子和根中分泌出更多的类黄酮类化合物。我们发现，番泻叶在液体培养时形成了结节状结构。对番泻根中分泌的黄酮类化合物进行了分析，试图弄清细菌接种是否诱导出一些特殊的黄酮类化合物。3)结瘤因子的化学合成根瘤菌产生的结瘤因子是结瘤的触发分子。我们开发了一种高效的该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.