链格孢菌毒素细交链孢菌酮酸对空心莲子草叶片生理生化特性的影响

Physiological Effects of Tenuazonic acid from Alternaria alternata on Alternanthera philoxeroides Leaves

以空心莲子草(Alternanthera philoxeroides)成株为材料,采用植物抗性生理分析测定技术研究了链格孢菌毒素细交链孢菌酮酸对空心莲子草叶片细胞膜透性、叶片内MDA含量、SOD、POD和CAT酶活性变化的影响。结果表明,空心莲子草叶片经细交链孢菌酮酸处理后,细胞膜透性随着细交链孢菌酮酸浓度的增加而增高,MDA含量在500μg/ml以下,随着毒素浓度的增加而升高,500μg/ml以上,又有所下降;随着细交链孢菌酮酸浓度的升高,SOD、POD、CAT活性下降,与对照相比,在1 000μg/ml时,SOD、POD和CAT活性达到最低,分别比对照(CK1)活性降低了86.24%、72.72%和82.05%。可见,细交链孢菌酮酸可严重降低空心莲子草叶片的生理生化活性,显示了其生防潜力。

Effects of tenuazonic acid from Alternaria alternata on membrane permeability,MDA content,SOD,POD and CAT activities in cells of Alternanthera philoxeroides leaves were studied by the analytical techniques in resistance physiology.The results showed that tenuazonic acid produced by Alternaria alternata could increase the membrane permeability and MDA content in cells of A.philoxeroides leaves.There was a positive correlation between the toxin concentrations and the change of permeability in cells,the higher the concentration,the higher the permeability in cells.MDA content increased with the increasing concentrations below 500 μg/ml,but decreased above 500 μg/ml.The changes in the activities of SOD,POD and CAT in cells were similar.They all decreased with the increasing toxin concentration.Compared with control,SOD,POD and CAT activities were the lowest at 1 000 μg/ml,decreased by 86.24%,72.72% and 82.05%,respectively.It could be concluded that tenuazonic acid could effectively depressed the physiological activities of A.philoxeroides leaves,which showed its potential for the biocontrol on A.philoxeroides.