An attempt to introduce nitrogen fixing ability into non-leguminous plants

将固氮结瘤能力引入非豆科植物是可能的，因为它们拥有与根瘤有关的大部分基因，并且非常容易产生假结瘤，随后进行几种处理。在本研究中，我们分离了植物与根瘤相关的各种基因，如早期结瘤蛋白基因、钙依赖蛋白激酶、热休克蛋白等，其中早期结瘤蛋白enod40和enod12基因是从田菁中分离出来的。Enod40的序列异质性由四种同源物组成。在几种植物中已经发现了两个enod40的同源物，我们在S.rostrata中发现了四个同源物，这是不寻常的。对enod40和enod12进行了原位杂交。在根瘤形成的早期，这些基因在根瘤原基周围表达。然而，尚未发现enod40的四个同源物之间的基因表达差异。接下来，我们得到了钙依赖蛋白激酶，它们的基因表达对结节的形成有反应。这些钙依赖蛋白激酶受细菌入侵和结节成熟的控制，但这些基因的作用尚不清楚。接下来，我们建立了罗氏葡萄球菌的细胞培养体系。该细胞培养物生长非常迅速，至少持续两年，该培养物将用于研究更准确地揭示根瘤菌与豆科植物之间的分子相互作用水平。与结瘤相关的基因很多，其分子机制仍处于黑暗的幕后。

It will be possible to introduce nitrogen fixing nodule-forming ability into non-leguminous plants because they have most of genes associated with root nodulation and very easily produce pseudonodules followed by several kinds of treatments. In this study we isolated various kinds of genes of plants, which are associated with root nodulation, such as early nodulin genes, calcium dependent protein kinases, heat shock proteins, etc. As early nodulins enod40 and enod12 genes were isolated from Sesbania rostrata. The enod40 showed sequence heterogeneity consisted of four kinds of homologs. Two homologs of enod40 has been found in several plant species, and our finding of four homologs in S.rostrata was unusual. In situ hybridization was carried out for the enod40 and enod12. These genes were expressed around the nodule primordia during the early stage of nodule formnation. However differences of gene expression among the four homologs of enod40 have not been revealed. Next, we got calcium dependent protein kinases of which gene expression responded to nodule formation. These calcium dependent protein kinases were controlled by the invasion of bacteria and maturation of nodules, but the roles of these genes has not been revealed. Next, we established cell culture of S.rostrata. The cell culture grows very rapidly and continuously for at least two years, and this culture will be used for the study to reveal more accurate level of molecular interaction between rhizobia and leguminous plants. So many genes are associated with the nodule-formation, and the molecular mechanism is still behind dark curtain.