Structure and function of a new plant growth substance, lepidimoide.

本研究从四个方面研究了一种新的化感物质——幻二醇酯的结构和功能。本文的研究结果如下：1)研究了化感物质异戊二醇在植物界的分布。所有被研究的植物（24种）的渗出物中都广泛含有槲寄生素。2)通过苋菜下胚轴伸长试验，研究了槲皮苷及其类似物的构效关系。lepidimoide促进植物生长活性的结构要求是-，- -不饱和羧酸上的糖醛酸衍生物通过-糖苷键和糖醛酸c -4,5位置的双键与鼠李糖结合。3)采用高效液相色谱法和生物测定法测定萌发期种子及其渗出液中戊二醇的含量。萌发的种子在吸胀后6小时内开始分泌大麻素，分泌的大麻素在4天内降解或代谢。此外，渗吸后还新合成了一部分渗出物。4)研究了异戊二酯对一些生理现象的影响。槲皮苷具有促进叶绿素和5-氨基乙酰丙酸合成和抑制衰老（如衰老或脱落）的作用。

In this research, we studied about the structure and function of a new allelopathic substance, lepidimoide at four other aspects. The results of this research are demonstrated as follows.1) The occurrence in the plant kingdom of the allelopathic substance, lepidimoide, was studied. Lepidimoide is widespread in the exudates from all plant species studied (24 species).2) The structure-activity relationship of lepidimoide and its analogues was investigated by means of Amaranthus hypocotyl elongation test. The structural requirements of lepidimoide for plant growth-promoting activities are the uronic acid derivatives on the alpha, beta-unsaturated carboxylate bonded to the rhamnose through an alpha-glucoside linkage and a double bond in the C-4,5 position in uronic acid.3) The contents of lepidimoide in the germinating seeds and their exudates were determined by HPLC and bioassay analysis during the germination period. The exudation of lepidimoide from germinating seeds began within 6 hr after imbibition and exuded lepidimoide degraded and/or metabolized within 4 days. Furthermore, a part of exuded lepidimoide was newly synthesized after imbibition.4) The effects of lepidimoide were studied on some physiological phenomena. Lepidimoide shows the effect for chlorophyll and 5-aminolevulinic acid synthesis and inhibition of aging (e.g.senescence or abscission).