Purification and Bioassay of Host-Selective AT-toxin from Alternaria alternata Causing Brown Spot of Tobacco
Purification and Bioassay of Host-Selective AT-toxin from Alternaria alternata Causing Brown Spot of Tobacco
复制标题
引起烟草褐斑病的链格孢菌宿主选择性 AT 毒素的纯化和生物测定
DOI：
10.3186/jjphytopath.56.628
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
S. Nishimura
中科院分区：
文献类型：
--
作者：
M. Kodama;Toshimasa Suzuki;H. Otani;K. Kohmoto;S. Nishimura
烟草赤星病的致病菌互隔交链孢（Alternaria alternata）在培养液和孢子萌发液中产生一种寄主选择性毒素（AT毒素）。用离子交换、柱层析、凝胶过滤和薄层层析等方法从该菌培养液中分离纯化了毒素。提纯的毒素在0.2μg/ml浓度下对感病和中抗品种烟草幼苗根系生长均有抑制作用，而在1和20μg/ml浓度下则分别引起叶片坏死。该毒素选择性地影响烟草叶片原生质体的活力，并引起叶片组织的氧吸收增加。在测试的几种植物中，只有属于烟草属的物种对毒素敏感。所有A.在孢子萌发液中产生毒素的烟草赤星病菌引起烟草褐斑病。用该毒素接种非致病性链格孢菌孢子，可使其成功侵染烟草叶片。这些结果表明，AT-毒素是烟草A属的一种寄主识别因子。互隔致病系统
Alternaria alternata tobacco pathotype, the causal organism of brown spot disease of tobacco, produced a host-selective toxin (named AT-toxin) in culture filtrates and spore-germination fluids. The toxin was purified from culture filtrates of this pathogen by a serial use of ion exchange, silicic acid and gel filtration columns, and thin layer chromatography. Purified toxin inhibited the seedling root growth of both susceptible and moderately resistant cultivars of tobacco at 0.2μg/ml, whereas the toxin induced necrosis on each leaf at 1 and 20μg/ml, respectively. The toxin selectively affected the viability of protoplasts derived from tobacco leaves, and caused an increase in the oxygen uptake by leaf tissues. Among several plants tested, only species belonging to the genus Nicotiana were sensitive to the toxin. All isolates of A. alternata that produced the toxin in spore-germination fluids caused brown spot disease of tobacco. Successful infection by nonpathogenic Alternaria on tobacco leaves was obtained when spores were inoculated with the toxin. These results indicate that AT-toxin is a host recognition factor in the genus Nicotiana-A. alternata pathosystem.