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感兴趣。近年来，我们从甜菜炭疽菌中发现了几种具有生理活性的化合物，包括甜菜单胞菌甜菜烯酮类化合物和除草剂APHIPDICONES类化合物，茄子交链格孢菌中的茄尼酮类化合物，芦笋中的Altiloxins类化合物，以及小豆中的异黄酮类和酚类化合物。马铃薯-蔗糖介质中茄那皮酮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)(+)-二倍体毒素的全合成和(-)-甜菜烯酮C的全合成为制备各种类似物提供了可能，这些类似物可用于结构-生物活性关系的研究和生物合成中间体的掺入。对赤霉素A的植物毒性代谢产物和合成中间体进行了抗毒素细胞的筛选，以获得抗性愈伤组织。(3)从小豆经头孢子菌B处理后的根部分离鉴定了抗真菌胁迫化合物。这些化合物主要是异黄酮类化合物。

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.