莲子草假隔链格孢毒素的致病机理研究

The pathogenic mechanism of toxin from Nimbya alternantherae to Alligator alternanthera

就莲子草假隔链格孢（Nimbya alternantherae）毒素Vuculic acid对空心莲子草（Alligaror alternanthera）的致病机理进行了研究．分别用不同含量的毒素溶液处理空心莲子草离体叶片，测定其对叶片组织细胞膜透性、丙二醛（MDA）含量、细胞内Na^＋、K^＋渗漏量以及过氧化物酶（POD）、抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT）活性的影响．结果表明，空心莲子草叶片组织浸出液的相对电导率随毒素含量的增高和处理时间的增加而增大；Na^＋的渗漏量高于对照；叶片组织MDA的含量也高于对照；空心莲子草叶片组织内CAT和POD活性在处理前、中期（1～6h），均随时间的延长呈上升趋势，但酶活性都低于对照；APX活性高于对照．

The pathogenic mechanism of toxin, vuculic acid from Nimbya alternantherae to alligatorweed （ Alligator altemanthera ） were studied. After A. altemanthera leaves were treated with different concentrations of the toxin from Nimbya altemantherae, its effects on cell membrane permeabihty, contents of malondidehyde （MDA）, Na^＋ and K^＋ leakage, and activities of peroxidase （POD）, ascorbatic peroxidase （APX）, and catalase （CAT） in A. altemanthera leaves in vitro were determinated. The results showed that relative conductivity increased with increase of toxin concentration and treatment time, Na^＋ leakage and MDA contents were higher than those of control （untreated with the toxin）. Activities of POD and CAT in treated leaves rised with lengthening of time within 6 hours after treatment, but they were lower than those in control leaves. However, the activity of APX in treated leaves was higher than that in control.