Dynamics of plant hormones in plant tumor formation and cell division

植物根瘤、遗传肿瘤、冠瘿等植物瘿的形成与植物生长激素含量的变化之间的关系主要通过生物测定和/或分析仪器进行分析。然而，由于采样的限制，这些方法不足以分析植物激素的特殊和时间变化的细微方面。本项目除上述方法外，还采用了结合GUS报告基因构建植物激素响应启动子的方法，如生长素DR5-GUS。所获得的主要结果总结如下1。将DR5-GUS导入肿瘤易感烟草F1植株（Nicotiana glauca x N.langsdorffii）。利用转化子分析发现，伤口诱导肿瘤发生的途径是生长素含量增加，生长素诱导基因如ngrob .2的表达增加。在体外无菌萌发时，下胚轴与根之间的部位自发发生肿瘤。由于对拟南芥DR5-GUS转化体幼苗的分析表明，在相似位点有生长素的积累，因此我们尝试用DR5-GUS对Lactuca sp.进行转化。所获得的转化子将有助于分析肿瘤的形成过程。气相色谱-质谱分析表明，在莲根瘤发育早期，生长素含量增加。为了进一步分析生长素在根瘤发育过程中的作用，我们成功分离了DR5-GUS转化体。GC-MS分析表明，在莲根瘤发育早期，GA含量显著增加。GA生物合成抑制剂抑制根瘤形成。然而，GA恢复了抑制作用。这些结果表明，赤霉素在根系发育早期参与了根瘤的形成。在水稻细胞中检测到吲哚-3-乙酰胺水解酶的高活性，该酶参与了水稻冠瘿生长素的生物合成。对酶活性进行了部分纯化，澄清了酶的性质。NgORF13在烟草遗传肿瘤中的表达也受到创伤的促进。茉莉酸盐被证明参与了这种促进。少

The relation between plant gall formation, such as root nodule, genetic tumor, crown gall and etc., and changes of the content of plant growth hormones has been analyzed mainly by bioassay and/or analytical instruments. However, these methods aren't enough to analyze minute aspects of special and temporal changes of plant hormones due to the restriction of sampling.In this project, in addition to these methods, the construct of plant-hormones-responsive promoter combined with GUS reporter gene, such as DR5-GUS for auxin, was used. The obtained major results are summarized below.1. DR5-GUS was introduced into tumor-proned tobacco F1 plant (Nicotiana glauca x N.langsdorffii). The analysis using the transformants showed the tumors will be induced by wound via increase of auxin content followed the promotion of expression of auxin-induced genes such as NgrolB.2. When the seeds of Lactuca sp. were germinated aseptically in vitro, tumors developed spontaneously at the site between hypocotyl … More and root. As analysis of the seedling of DR5-GUS transformants of Arabidopsis showed the accumulation of auxin at the similar site, transformation of Lactuca sp. by DR5-GUS was attempted. The obtained transformants will be useful for analysis of tumor formation processes.3. GC-MS analysis showed that the content of auxin increased at the early stage of root nodule development in Lotus japonicus. For further analysis of auxin function in the development of root nodule, DR5-GUS transformants were successfully isolated.4. GC-MS analysis showed that in the early stage of the development of, root nodules in Lotus japonicus, GA content increased remarkably. Inhibitors of GA biosynthesis inhibited the root nodule formation. However, the inhibition was recovered by GA. These results suggest that GA involved in root nodule formation at early stage of development.5. High activity of indole-3-acetamide hydrolase, which involve in auxin biosynthesis of crown gall, was detected in rice cells. The enzymatic activity was partially purified and the nature of enzyme was clarified.It was also found that the expression of NgORF13 in tobacco genetic tumor was promoted by wound. Jasmonate was shown to be involved in the promotion. Less