拟南芥种子萌发及幼苗生长对干旱和NaCl胁迫的响应

Responses of seed germination and seedling growth of Arabidopsis thaliana to drought and NaCl stress

为获得胁迫因子处理拟南芥的最佳浓度及其生长的临界胁迫浓度,以期进一步采用拟南芥基因缺失突变体,以PEG模拟干旱胁迫和NaCl作为盐胁迫因子,在室内培养条件下探讨了拟南芥种子萌发、幼苗生长、根长及渗透调节物质丙二醛和脯氨酸含量的变化。结果发现:干旱和高盐胁迫影响种子萌发的半抑制浓度分别为10%(PEG-6000)和150 mmol/L;幼苗生长的临界值分别为25%(PEG-6000)和250 mmol/L NaCl。随着干旱胁迫和NaCl胁迫程度的增加,丙二醛及脯氨酸的含量均明显增加。表明随着胁迫条件的加重,拟南芥幼苗质膜受到氧化性伤害,并通过合成脯氨酸等渗透调节物质的机制对胁迫因子产生响应。

This paper studies the polyethylene glycol （PEG-6000） employed as osmoticum for simulating drought and NaCl for salt stress to identify the seed germination and seedling growth of Arabidopsis. Results showed that drought stress or high salinity retards seed germination of Arabidopsis in the early stage. The rate of seed germination and seedling growth decreased significantly and semi-inhibitory concentration was 10% （PEG-6000） and 150 mmol/L. The critical value of seed growth was 25 % （PEG-6000） and 250 mmol/L NaCl respectively. The contents of malondialde- hyde （MDA） and proline increased remarkably with the increase of PEG or NaCl concentration. These findings indicate that the osmoticum and salt stress might damage the cell membrane of the seedling and the plants responded to stress by compounded proline contents.