摘要
用由稻瘟病菌gp d基因启动子和终止子序列控制的、以粗糙脉孢菌的微管蛋白β-tubu lin(Bm 1)突变基因为选择标记的表达载体,转化稻瘟病菌0742野生型菌株,获得了两株具有苯菌灵抗性的菌株M 1和M 2。但Sou thern杂交表明,这两个菌株并不是由于质粒转化而获得苯菌灵抗性。对稻瘟病菌0742野生型及突变体M 1、M 2的β-tubu lin基因的序列比对分析表明,突变体M 1在内源β-tubu lin基因的第56、178、1704位置上发生了点突变,M 2在第56、899、1040、1389、1704位置上发生了点突变,导致M 1的352位氨基酸由苏氨酸变成了丙氨酸,M 2的107、154、270、352位氨基酸分别由苏氨酸、赖氨酸、苯丙氨酸、苏氨酸变为丙氨酸、谷氨酸、丝氨酸、丙氨酸。计算机分析显示M 1和M 2突变体β-tubu lin基因编码的蛋白质疏水性发生了微弱改变,结构域没有受到影响。该发现为开发新的稻瘟病菌遗传选择标记提供依据。
A transformation vector with the mutated Bml gene from Neurospora crassa as the selectable marker to benomyl and under the transcriptional control of the gpd promoter and terminator from the rice blast fungus, Magnaporthe grisea （isolate 0742）, was used to transform M. grisea spheroplasts and two benomyl-resistant transformants （M1 and M2） were obtained. However, Southern analysis showed that the resistance of the transformants was not linked to the vector plasmid. Sequence comparison of the gene encoding β-tubulin from the wild-type and the mutants revealed 3 point mutations at position 56, 178, 1704 of the coding strand for mutant M1 and 5 point mutations at position 56, 899, 1040, 1389, 1704 of the coding strand for mutant M2. These resulted in the substitution of amino acid in M1, from threonine to alanine （position 352）, and in M2, from threonine to alanine （position 107）, from lysine to glutamic acid （position 154）, from phenylalanine to serine （position 270）, and from threonine to alanine （position 352）. The finding of benomyl-resistant mutation may lead to the development of a new genetic marker for M. grisea.
出处
《广西农业生物科学》
CAS
CSCD
2006年第1期11-17,共7页
Journal of Guangxi Agricultural and Biological Science
基金
国家攻关重大专项"稻瘟病菌致病性功能基因组学"资助项目(2002BA711A15)
