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

在非豆科植物中引入固氮结瘤能力是可能的，因为它们具有大部分根瘤相关基因，并且很容易产生假结节，然后进行几种处理。本研究分离了多种与根结瘤相关的植物基因，如早期根瘤蛋白基因、钙依赖性蛋白激酶、热休克蛋白等。从田菁中分离到早期结瘤蛋白enod40和enod12基因。enod40表现出序列异质性，包括4种同源物。在一些植物中已经发现了两个同源物，而我们在玫瑰草中发现了四个同源物是不寻常的。对enod40和enod12进行原位杂交。这些基因在结节形成早期在结节原基周围表达。然而，目前还没有发现四个同源基因enod40的基因表达差异。接下来，我们得到了钙依赖性蛋白激酶，其基因表达与结节形成有关。这些钙依赖性蛋白激酶受到细菌入侵和结节成熟的控制，但这些基因的作用尚未揭示。接下来，我们建立了rostrata的细胞培养。培养的细胞生长速度非常快，至少可以持续2年以上，该培养将用于研究根瘤菌与豆科植物之间更准确的分子相互作用水平。如此多的基因与结节的形成有关，其分子机制仍处于黑暗之中。

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.