Analysis of Biosynthesis and Physiological Activity of Lepidimoide-like Substance in Arabidopsis thaliana

本论文以拟南芥为材料，研究了新的植物生长调节物质lepidimoide的合成及其生理活性.我们通过高效液相色谱法和薄层层析法对Lepidimoide-like substance（LM）进行了分析，明确了拟南芥生长植物和鹰嘴豆种子的几乎所有器官（种子、莲座叶、茎、根、花序和未成熟的果实）都含有LM。2.我们明确了LM在拟南芥中表现出双面活性，即：e.促进下胚轴伸长、子叶生长和子叶-叶柄伸长，但抑制根的伸长。LM降低了莲座叶的生长量、株高、单株鲜重、角果数、种子产量。但LM在不减少莲座叶数的情况下促进了开花，表明LM在较短的时间内促进了叶片的发育。LM的这种效应加速了植物的生命周期。从“仙台拟南芥种子库”的大量生态型中寻找拟南芥的敏感品系，筛选出2个下胚轴伸长和子叶生长显著促进的品系（Aa-0，Bur-0）.紫云英科种子的种皮细胞具有中央隆起的分化结构，LM可能是从种皮细胞中分泌出来的。因此，我们研究了新的相关芸苔属物种的中央隆起的形态。观察到的10种植物都具有分泌粘液的中央突起。而缺失中央突起的突变体种子分泌LM的量也只有野生型的一半左右。我们对各种草本植物的幼苗进行LM处理，并根据植物种类和生长条件识别各种相反的效果。

We studied on the synthesis and the physiological activities of the novel plant growth regulating substance, lepidimoide, using Arabidopsis thaliana.1. We analyzed lepidimoide-like substance (LM) by means of HPLC and TLC, and clarified that almost organs (seeds, rosette leaves, stems, roots, inflorescences and immature fruits) of growing plants of A.thaliana, and the seeds of Capsella Bursa-pastris included LM.2. We made clear that LM showed the two-faced activity in A.thaliana, i. e. promotion of hypocotyl elongation, cotyledon growth and cotyledon-petiole elongation, but inhibition of root elongation. LM reduced the growth of rosette leaves, plant heights, fresh weights of plants, pod number, yield of seeds. However, LM hastened flowering without decreasing number of rosette leaves suggesting LM accelerates the development of leaves within a shorter period. This effect of LM hastens the life cycle of plants.3. We made a search for sensitive lines of A.thallana from a large number of ecotypes in "The Sendai Arabidopsis Seed Stock Center", and selected 2 lines (Aa-0, Bur-0), hypocotyl elongation and cotyledon growth of which were markedlypromoted.4. The cells of seed coat of Brassicaceae have a differential structure, central elevation, from which LM seemed to be secreted. Therefore, we investigated the morphosis of the central elevations of newly related Brassica species. We recognized that all the plants (10 species) observed have the central elevation which secreted mucilage. However, the seeds of a mutant lacking the central elevation also secreted LM at about half amount of that in wild types.5. We treated LM to the seedlings of various herbaceous plants, and recognized various opposite effects according to plant species and growth conditions.