Studies on the Production of Phytotoxins and Their Application for Plant Protection

植物病原真菌产生许多植物毒素，目前人们对它们在致病性中的作用以及它们的化合物和衍生物在农用化学品中的应用很感兴趣。近年来，我们陆续发现了几种具有生理活性的化合物，包括槟榔科植物中的甜菜烯酮和芹菜烷类化合物，茄花属植物中的茄酮类化合物，天门冬属植物中的altiloxins，以及赤豆中经b型头孢菌处理过的异黄酮和酚类化合物。(1)甜菜糖汁培养基中蚜虫烷的产量增加。在马铃薯-蔗糖培养基上对茄奈酮A的生物合成研究表明，该植物毒素是通过八肽途径生物合成的。(2)通过(+)-双藻毒素和(-)-倍烯酮C的全合成，制备了多种类似物，可用于研究其结构-生物活性关系和在生物合成中间体中的掺入。对抗毒素细胞进行了抗阿替洛辛A植物毒性代谢物和合成中间体的筛选，以获得抗愈伤组织。(3)从小豆经B型头孢菌（Cephalosporium B）处理后的根中分离鉴定出抗真菌胁迫化合物。B型头孢菌是一种引起寄主植物褐腐病的致病真菌。这些化合物主要是异黄酮。

Plant Pathogenic fungi produce a number of phytotoxins and there is current interest in their roles in pathogenicity as well as in the use of their compounds and derivatives for agrochemicals. Recently, we have found several physiologically active compounds, betaenones and aphidicolanes from Phoma Betae, solanapyrones from Alternaria Solani, altiloxins from Phoma Asparagi, and isoflavonoids and phenolic compounds from azuki bean treated with Cephalosporium gregatum Type B. Outline of research work is summarized as follows.(1) Production of aphidicolanes increased in the culture medium of beet sugar juice. Biosynthetic study of solanapyrone A on potato-sucrose medium revealed that the phytotoxin is biosynthesized through octaketide pathway.(2) Total synthesis of(+)-diplodiatoxin and then (-)-betaenone C have made possible to prepare various analogues which are useful for the studies of structure-bioactivity relationship and incorporation in biosynthetic intermediates. Selection of toxin- resistant cells for phytotoxic metabolites and synthetic intermediates of altiloxin A has been carried out to give resistant calli.(3) Antifungal stress compounds were isolated and identified from the roots of adzuki bean that had been treated with Cephalosporium type B, which is an avirulent strain of a pathogenic fungus causing brown stem rot disease on the host plant. These compounds were mainly isoflavones.