Cloning of genes concerned in pathogenicity of plant pathogens

本项目的目的是从分子水平上分析植物病原菌的致病性，为病害防治奠定基础.刺蛾刺入力的要素分析。C. lagenarium，附着胞不能穿透硝化纤维。扫描电镜观察结果表明，在Czapek液体培养基中，一个突变体（83182）形成了一个穿透钉，并恢复了附着胞的穿透，而没有形成晕。因此，发现突变体83182缺乏纤维素酶分泌系统。将scytalon转化为THN的黑色素生物合成酶的纯化。从宫边旋孢霉（Cochliobolus miyabeanus）菌丝体中纯化了一种黑色素生物合成酶，即将鲨烯酮转化为THN的鲨烯酮转化酶。该酶的最适pH值为8.2，分子量为23,000 Da，用氨基酸分析仪和序列分析仪测定了该酶N-末端的氨基酸序列 ...更多信息 合成对应于氨基酸序列的氨基酸序列。利用该引物筛选mRNA的cDNA，得到12个克隆.宫城旋孢霉黑色素生物合成相关基因的遗传分析。色突变体C.分离黑色素生物合成缺陷的Miyabeanus。虽然野生型菌株KU-13形成深绿色菌落，但颜色突变体形成白色、棕色和灰色或白色菌落，并分泌红色色素。从分泌红色素的白色突变株scy中分离出一种能恢复白化病突变株alm-1黑化的黑色素前体，经鉴定为scytalone。这表明scy突变体在scytalone向THN的转化中存在缺陷，并且该真菌的黑色素是由1，8-DHN形成的pentaketide来源。突变株brm不能将1，3，8-THN转化为耶美隆。还分离了白化病突变体alm-2，其着色不能通过施用scytalone而恢复。通过颜色突变体间的杂交试验表明，alm-1。ALM-2和BRM是相似的，并且Scy分离独立地调节Pentaketide环化和Scytalone的转化。少

The aim of this project is to analyze the pathogenicity of plant pathogens at molecular lecel, and to lay the foundation of disease control.1. The analysis of essential factors for penetration of colletorichum laqenarium. Three mutants of C. lagenarium, with appressoria that could not penetrate nitrocellulose. From the results of scanning electron microscopic observation, one mutant (83182) formed a penetration peg and restored appressorial penetration swithout halo formation in the presence of Czapek liquid medium. Therefore, it found that mutant 83182 is deficient in secretion system for cellulase.2. Purification of a melanin biosyunthesis enzyme converting scytalon to THN. a melanin biosynthe-tic enzyme, scytalone dehydratase, which converts scytalone to thn was purified from mycelia of cochliobolus miyabeanus. This enzyme had an optimum pH near 8.2 and mol w 23,000 Da. The amino acid sequence of N"terminal of this enzyme was decided using an amino acid analyzer and origonucleotides … More corresponded to the amino acid sequence were synthesized. The origonucleotide was used for screening of cDNA of mRNA and 12 clones were obteined.3. Genetic analysis of genes involved in melanin biosynthesis of cochliobolus miyabeanus. color mutants of C. miyabeanus defective in melanin biosynthesis were isolated. Although the wild-type strain KU-13 formed dark green colonies, color mutants formed white,brown, and gray or white colonies with red pigment secretion. From the white mutant which secreted red pigment, designated scy, a melanin precoursor which restored melanization of albino mutants alm-l was isolated and identified as scytalone. This indicated that scy mutant was defective in the convertion of scytalone to THN and that melanin of this fungus is of pentaketide origin formed from 1,8-DHN. Grown mutant brm were considered to be defective in the convertion of 1,3,8-THN to yermelone. Albino mutant alm-2 whose coloration was not restored by application of scytalone were also isolated. From crossing experiments among the color mutants, it was indicated that alm-1. alm-2 and brm were liked and that scy segregates independently regulating the pentaketide cyclization and vonversion of scytalone. Less