Dynamic Molecular aspects on Plant Disease and Defense Mechanism

本项目从分子水平上研究了病原菌入侵植物过程中所涉及的植物毒素和植物抵抗入侵微生物的防御物质（胁迫化合物）。研究结果总结如下.阐明了茄链格孢菌毒素代谢产物链格孢酸的立体化学结构，完成了该毒素的全合成。从该菌培养滤液中分离得到了几种与链格孢酸有关的植物毒素.确定了腐烂病菌中植物毒性化合物的结构.从豆科植物中分离得到了许多抗逆化合物，并对其生物有机化学进行了研究.云杉长喙壳菌代谢产物的结构为（3R，5 R）-（+）-3-羟基十四烷-5-酮及其衍生物。从冷杉隐孢子虫中分离得到的脱落甾醇的结构经核磁共振谱和圆二色性实验确定为21-去甲-24-亚甲基-5 α-胆甾-7，17（20）-E-二烯-4 β; 19-环氧-3 β-01. AAL毒素（一种宿主特异性毒素）的降解和模型氨基三醇的合成使我们能够确定绝对构型为2S、4S和5 R。

This project was undertaken to investigate in molecular level on the phytotoxins involved in the invasion of plants by pathogens and defense substance (stress compounds) involved in the resistance of plants to the invading microorganisms. Summary of research results are as follows.1. Stereochemistry of alternaric acid, a phytotoxic metabolite of Alternaric solani, have been elucidated, and total synthesis of the phytotoxin has been completed. Several phytoxines related to alternaric acid have been isolated from culture filtrate of the fungus.2. The structures of phytotoxic compounds from Valsa ambiens have been determined.3. Many stress compounds were isolated from Leguminosae and their bioorganic chemistry has been studied.4. The structures of the metabolites of Ceratocystis piceae were revealed to be (3R, 5R)-(+)-3-hydroxytetradecan-5-olide and its derivatives. The structure of abscisterol isolated from Cryptosporiopsis abietina has been determined as 21-nor-24-methylene-5alpha-cholesta-7,17(20)-E-diene-4beta ; 19-epoxy-3beta-01 from NMR spectra and CD experiments.5. Degradation of AAL-toxin, a host-specific toxin and synthesis of model aminotriols allowed us to determine the absolute configuration as 2S, 4S and 5R.