Abstract:

Oxalic acid is a toxin produced when plant is attacked by Sclerotinia sclerotiorum. An oxalic acid insensitive mutant named 275-7 was screened from the T-DNA insertion mutant library of Arabidopsis thaliana (about 1 000 lines) using 1/2 MS with 3 mmol/L oxalic acid. In vivo leaf inoculation test was undertaken, in order to assess the resistance to Sclerotinia sclerotiorum of mutant 275-7. The result indicated that mutant 275-7 exhibited a higher resistance to S. sclerotiorum than the wild type Arabidopsis (P<0.05). Fluorescence real-time quantitative PCR result showed that the expression of jasmonic acid (JA)-responsive marker gene PDF1.2 in 275-7 were significantly up-regulated (12 fold) in comparison with the wild type plants, but the expression level of salicylic acid (SA)-responsive marker gene PR1 was not significantly different from the wild type. This suggested that the enhanced resistance to S. sclerotiorum in mutant 275-7 might be mediated through JA signal pathway.

Key words: Arabidopsis thaliana, mutant, Sclerotinia sclerotiorum, resistance, oxalic acid

摘要：

草酸是核盘菌致病过程中产生的毒素因子。以菌核病菌毒素草酸（3 mmol/L）为筛选压,从1 000个拟南芥T-DNA插入突变体中筛选出了1个草酸不敏感突变体,命名为275-7。通过拟南芥活体接种对突变体275-7进行菌核病抗性鉴定,与野生型相比,突变体275-7对菌核病的抗性显著增强（P<0.05）;荧光定量PCR检测结果表明,275-7中茉莉酸途径的标志基因PDF1.2的表达量是野生型的12倍,而水杨酸途径的标志基因PR1基因的表达量与野生型比较无差异。推测拟南芥突变体275-7可能通过增强水杨酸介导的防卫反应,从而表现出对菌核病的抗性。

关键词: 拟南芥;突变体;菌核病 ;抗性;草酸