BIOLOGICAL ACTIVITIES OF AK-TOXINS I AND II HOST-SPECIFIC TOXINS FROM ALTERNARIA-ALTERNATA JAPANESE PEAR PATHOTYPE
BIOLOGICAL ACTIVITIES OF AK-TOXINS I AND II HOST-SPECIFIC TOXINS FROM ALTERNARIA-ALTERNATA JAPANESE PEAR PATHOTYPE
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DOI：
10.3186/jjphytopath.51.285
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发表时间：
1985-01-01
期刊：
影响因子：
--
通讯作者：
FUKAMI H
中科院分区：
文献类型：
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作者：
OTANI H;KOHMOTO K;FUKAMI H
对赤星病菌AK毒素I、II进行了生物活性测定。两种制剂对感病的日本梨品种均有毒害作用，但对抗病品种和非寄主植株无毒害作用。AK-毒素I和II在5倍。10~(-9)M和10~(-7)M分别诱导感病梨叶片特有的叶脉坏死和迅速的钾流失。剂量-反应关系表明，AK-毒素II的活性约为AK-毒素I的十分之一。AK-毒素I和AK-毒素II在10~(-4)M时不影响抗病叶片。在AK-毒素I和AK-毒素II处理的感病梨细胞中，在电子显微镜下观察到质膜内陷和细胞壁降解。当AK-毒素I或II加入到互隔交链孢子的无毒孢子中时，该孢子和致病孢子一样能侵入感病组织。这些结果表明，AK毒素I和II的纯样品符合宿主特异性毒素的标准，并具有与我们以前的半纯化AK毒素制剂相同的生物学活性。
Pure samples of chemically characterized AK-toxins I and II from Alternaria alternata Japanese pear pathotype were examined for their biological activities. Both preparations were toxic to Japanese pear cultivars susceptible to the pathogen, but were harmless to resistant pear cultivars and non-host plants tested. AK-toxins I and II at 5 .times. 10-9 M and 10-7 M, respectively, induced characteristic veinal necrosis and rapid K- loss on susceptible pear leaves. The dose-response relationship revealed that the activity of AK-toxin II was about one-tenth that of AK-toxin I. AK-toxins I and II at 10-4 M did not affect resistant pear leaves. In susceptible pear cells treated with AK-toxin I or II, invagination of the plasma membrane and degradation of the cell wall were observed under an electron microscope. When AK-toxin I or II was added to avirulent spores of A. alternata, the spores could invade susceptible tissues, just as did the virulent spores. These results show that pure samples of AK-toxins I and II fall under the criteria of host-specific toxin, and have the same biological activity as our previous semipurified AK-toxin preparation.